This standard specifies the application for residential and civil construction works, and does not apply to industrial buildings and special works.

1. General rules

1.1. In addition to complying with the provisions of this standard, the construction of finishing works for acceptance of works must also comply with the provisions of occupational safety, fire prevention and fighting as well as other relevant standards promulgated by the State.

1.2. For prefabricated and pre-processed structures in factories, finishing works are carried out right in the manufacturing process and must comply with separate regulations.

1.3. Before carrying out the finishing of each part or the whole work, the following basic tasks must be completed:

– Seal the joints between blocks or assembled panels of the work, especially seal the connecting steel details of reinforced concrete structural members.

– Install and caulk window and door frames, fill mortar into the gaps between the frames and walls.

– Construct the underlayment layers of the floors;

– Construct waterproofing layers for roofs and toilets, bathrooms… to ensure no water leakage or odor escaping through the pipe and drain sealing gaps.

– Install railings and construct waterproofing layers in balcony areas, loggias, etc.

– Install water supply and drainage systems, check the connections and terminals of the piping system.

– Install concealed wiring for lighting, telephone, and broadcasting systems, and embedded electrical outlets.

– When necessary, plastering, tiling, and cladding must be carried out right at the locations where sanitary equipment, steam pipes, heat and water supply will be installed,…

1.4. The finishing works must be carried out in the sequence shown in Table 1, unless the design specifies a different implementation sequence.

1.5. The sequence of finishing works for each room and each work must be clearly recorded in the construction drawings.

1.6. For works under 5 stories, the finishing works should start from the top story down, after completing the installation works on each part or the whole work, except for special cases at the request of the investor.

For works of 5 stories or more, the finishing works should start from the lower story up. In that case, at least two stories of the work must have completed the assembly and the tasks specified in Article 1.3. The design must have safety protection measures for people and equipment during the finishing process on the lower stories and avoid impacts and vibrations that cause damage to the finished surface. It is not allowed to simultaneously carry out the assembly work on the outside of the rooms and the stories where the finishing is being done.

1.7. Interior finishing of the works. If walls, columns and other structures in the works are built with loose masonry materials, plastering can be done right after completing that story.

If using lime mortar, finishing plastering is allowed after completing the ceiling installation of that story.

1.8. For single-story houses and the top stories of multi-story buildings, finishing works can only begin after the roofing is completed.

For walls with wooden frames and assembled planks, construction or finishing can be carried out right after completing the ceiling and roof installation.

1.9. Finishing works in the construction on plaster layers, special paint, tile, and cladding such as: waterproofing, soundproofing, heat-resistant, fireproofing, acid-resistant, alkali-resistant, radiation shielding… must comply with the instructions.

Table 1 – Sequence of interior finishing works

1.10. Materials used for finishing works: Materials and products used in finishing works must comply with the standard requirements as well as specific instructions of the approved design.

1.11. In case the materials and products used for finishing are brought to the site without markings on the packaging or the packaging is no longer intact, it is necessary to test and determine the characteristic indicators of the physical and mechanical properties of that type of material.

It is not allowed to use expired materials or products. If further use is desired, testing must be carried out, and the quality must satisfy the requirements stated in the design.

2. Plastering

2.1. The plaster layer to cover the surfaces of brick and stone structures, concrete and reinforced concrete structures, tower structures (if necessary), bamboo, wood structures… must have specific regulations for each type of structure and mortar type and plastering mortar quality, construction sequence…

2.2. Before plastering, the surface of the structure must be cleaned, washed of dust, moss, oil stains, and wetted; projections, dents, rough spots, lime and mortar lumps stuck on the surface of the structure must be filled or chiseled to make it flat.

2.3. If the surface of the structure does not have enough roughness for the mortar to adhere, such as concrete surfaces cast in steel formwork, metal surfaces, plywood surfaces, planed wood surfaces… before plastering, it must be processed to create roughness by sand blasting or cement mortar processing, splashing sand on the surface of the structure, or making indentations. A few test plasters must be done to determine the necessary adhesion.

2.4. At the junctions between two structures made of different materials, before plastering, a layer of steel mesh must be installed covering the thickness of the joint and extending on both sides for at least 15 to 20cm. The mesh size should not be larger than 4 to 5cm.

2.5. The thickness of the mortar layer depends on the quality of the plastered surface, the type of structure, the type of mortar used, and the plastering method.

The thickness of the ceiling plaster layer is 10 to 15mm; if plastering thicker, there must be measures to prevent sagging by plastering on steel mesh or performing multi-layer plastering.

The thickness of the flat plaster layer for ordinary wall structures should not exceed 12mm when plastering with higher quality – not exceeding 15mm and with particularly high quality – not exceeding 20mm.

2.6. When plastering thicker than 8mm, it must be done in multiple layers, each layer not thicker than 8mm and not thinner than 5mm (when plastering with lime mortar).

Use a trowel to make indentation grids to increase the adhesion between layers. The indentation grid has a side of about 60mm, with a depth of 2 to 3mm.

The plaster layer must be flat. When the previous layer hardens, the next layer is plastered. If the previous layer has dried, it must be wetted before plastering the next layer.

– If plastering with cement mortar, the thickness of each layer must not exceed 5mm. The leveling plaster layer must not be thicker than 2mm. For decorative plaster (polished plaster, washed plaster, chiseled plaster…), the final plaster layer is allowed to be 5mm thick. The outer plaster layer is also done when the base layers have hardened.

2.7. In rooms that are regularly damp such as toilets, bathrooms, the plaster layer must use cement mortar for waterproofing and increasing the adhesion between the plaster layers.

2.8. Mortar used for rough plastering the base layers must be sieved through a 3x3mm mesh; mortar used for the finishing layer with a smooth outer surface must be sieved through a 1.5×1.5mm mesh.

2.9. The slump of the mortar at the beginning of plastering onto the structure depends on the conditions and construction methods specified in Table 2.

Table 2 – Slump of plastering mortar

2.10. Splatter dash – when creating a rough plaster surface (splatter dash), a mortar sprayer can be used to spray the mortar onto the wall, or a brush can be used to splash multiple times. When the previous layer hardens, the next layer is splashed. The splashed mortar must adhere evenly to the plastered surface.

2.11. Exposed aggregate plaster – the exposed aggregate plaster surface is made of cement mortar mixed with pebbles or crushed stone with a grain size of 6-12mm. When the mortar hardens after plastering for about 4-5 hours (depending on time and humidity), the outer mortar layer is cleaned to expose the pebbles or stones.

2.12. Polished plaster – First, a base plaster layer must be made smooth. The thickness of the base layer is 10-15mm, using cement mortar with yellow sand in a 1:4 ratio (cement: yellow sand). Use a trowel to make indentation grids on this base layer and wait for the base layer to dry. The outer plaster layer consists of white cement, fine stone powder, color powder, and aggregates with sizes from 5mm to 8mm. The procedure is as follows: mix the stone powder with white cement, then mix with the color powder. When satisfied with this powder mixture, add the aggregates and mix well. Finally, add water to make a flexible mortar. Use a trowel to vigorously rub this mortar layer onto the plaster surface and make it smooth. After this mortar layer has been set for 24 hours, use a coarse grinding stone to grind and expose the stones and make the surface flat. When grinding, gently pour water to wash away the stone powder. The more thoroughly it is ground, the more beautiful the plaster surface will be later.

During grinding, there may be chipping or dents due to detachment of a few stone particles. Take a mixture of white cement, stone powder, and color to fill the dents on the newly ground surface. Wait 3 or 4 days and then grind again with a fine grinding stone. Let the finely ground stone surface dry, then polish with clear wax to let the wax layer penetrate deeply into the plaster layer.

2.13. Washed plaster – the initial washed plaster work is also carried out similarly to polished plaster. When the plaster mortar has hardened, ensuring the adhesion of the aggregates to the mortar and the inner plaster layer, about 2 hours later, wash with water using a soft brush. The plaster surface must be clean and evenly exposed, without stains or localized mortar lumps. The plaster surface must be carefully preserved until completely dry.

2.14. Chiseled plaster – the plastering work is also done like polished plaster, washed plaster, and with a similar mortar mixture. After plastering for about 6 to 7 days, chiseling is carried out. Before chiseling, it is necessary to draw the border lines, ribs, and decorative patterns according to the design and chisel on the surface bounded by those lines.

The chiseling tool is a pointed hammer. The chiseling direction must be perpendicular to the plaster surface and very even-handed to expose the stone particles and have a uniform color.

2.15. In case of high requirements for the quality of the plaster surface such as flatness, accuracy of curved lines, then before plastering, reference points or thickness control points of the plaster layer must be installed as a standard for construction.

2.16. When the plaster mortar layer is not yet hardened, it must not be impacted or vibrated. Protect the plaster surface from water running through the particles and from sudden and localized heat or cold.

2.17. For interior plaster mortar, it is not allowed to use additives containing chlorine.

2.18. When accepting plastering works, the following requirements must be satisfied:

– The plaster mortar layer must adhere firmly to the structure, without peeling or hollowness. Check the adhesion by lightly tapping on the plaster surface. All hollow-sounding spots must be removed and re-plastered.

– The plaster mortar surface must not have crazing cracks, mortar drip marks, trowel marks, localized bumps, roughness, as well as other defects at corners, edges, wall base moldings, door base moldings, junctions with locations of electrical equipment, sanitary drainage…

– The edge lines of the walls must be straight and sharp. Right angles must be checked with a square ruler. The edges of windows and doors must be parallel to each other. The top surface of the window sill must have a slope according to the design. The plaster mortar layer must be embedded under the frame trim by at least 10mm.

2.19. The allowable deviations of the plaster surface are checked according to the values given in Table 3.

Table 3 – Allowable deviations of finished plaster surfaces

3. Tiling and topping works

3.1. Tiling works

3.1.1. Tiling works can only begin when the construction work on the structure above and around has been completed, including: plastering of ceilings or suspended ceilings, plastering and cladding of walls. The tiled surface must be flat and cleaned.

3.1.2. Tiling materials must be of the correct type and size, color, and create the designed pattern. The tiles or tiling bricks must be square, not warped, chipped at corners, and have no other defects on the surface. Cut bricks must have a flat cut edge.

3.1.3. The tiled surface must be flat, without localized bumps, dents. Check with a 2m long ruler. The gap between the tiled surface and the ruler must not exceed 3mm. The slope and slope direction of the tiled surface must follow the design. Checking the slope is done using a level, water pouring test, or rolling a 10mm diameter steel ball. If there are dents creating water puddles, it must be removed and re-tiled.

3.1.4. Between the tiles and the floor, there must be a full mortar bed. Checking the compactness of the mortar bonding layer is done by lightly tapping on the tiled surface. If there are any hollow spots, remove and re-tile.

3.1.5. The thickness of the bedding cement mortar layer must not exceed 15mm. The joints between tiles must not exceed 1.5mm and be fully filled with pure cement mixed with water into a slurry paste. When the joints have not been filled, walking or strong impacts on the tiled surface causing tile detachment are not allowed. After joint filling, immediately wash to make the joint lines sharp, and at the same time, clean the tiled surface without leaving cement residue.

3.1.6. At locations with waterproofing requirements, before plastering, it is necessary to check the quality of the waterproofing layer and other details (such as sealing joints between assembled components, sealing around the water supply system…). The thickness of the bitumen waterproofing layer must not exceed 3mm.

3.1.7. The junctions between tiled joints, as well as between tiled joints and wall bases, must be fully filled with cement mortar.

3.1.8. The tiled surface must be constructed according to the design in terms of color, pattern, and decorative borders. If the tiled surface is natural stone tiles, adjacent tiles must have harmonious colors and veins, without creating a stark contrast.

3.1.9. When tiling with precious stones, the cut tiles must be pre-processed at the factory. When tiling with glazed ceramic tiles, the cut tiles should be processed on-site. Cutting and grinding the edges must ensure clean cut lines and even joints.

3.1.10. When tiling wooden floors, the floorboards must be nailed onto a solid wooden frame. The dimensions of the frame structure depend on the length and cross-section of the assembled floorboards. Between the floor supporting frame and the building’s base, there must be very stable pads. After assembling the wooden floor surface, it must be planed smooth, then sanded from coarse to fine, and finally polished with wax.

3.1.11. When tiling with synthetic plastic sheets, if the base is plywood, the entire perimeter of the sheet must be stapled with copper or zinc-plated nails, with nails spaced no more than 200mm apart and no more than 20mm from the sheet edge. In the middle of the sheet, nails are driven in a grid pattern spaced 35-40cm apart. Between two adjacent plastic floor sheets, there must be an overlap of at least 40mm. At the wall base moldings, the plastic sheet is fastened with wooden strips. If the floor base is concrete, wooden inserts must be pre-embedded at the nailing locations. If using adhesive to bond the plastic sheets, the bonding surface must be ground flat and brushed clean of dust before applying the adhesive layer. The adhesive is applied to the base perpendicular to the direction of the plastic floor roll. Bonding is done in segments, each 30-40mm long. Pressure must be applied strongly on the newly bonded area to make the plastic sheet adhere tightly to the base. When using adhesive, nailing is not required. If two plastic sheets are bonded adjacent to each other, they must be perfectly parallel and tightly joined, without allowing the sheet edges to overlap.

3.1.12. Do not use wooden flooring for rooms that are regularly damp, rooms that are easily flammable, and have high temperatures. Do not use plastic sheets for floor tiling.

3.1.13. The tiled surface must meet the requirements of height, flatness, slope, and adhesion to the tiled base. The thickness of the bedding mortar layer, the thickness of the mortar joints, color, decorative shapes… must follow the design.

3.2. Topping works

3.2.1. The topping layer is applied on brick, various concrete, or reinforced concrete bases. Before topping, the base structure must be stable and flat, and scrubbed clean of oil stains, moss, and dirt.

3.2.2. To ensure good adhesion between the topping mortar layer and the base, if the base surface is dry, it must be wetted and the surface roughened. If there is a bedding layer, the surface must be scored with a grid pattern having sides of 10 to 15cm.

3.2.3. The final topping layer is made of cement-sand mortar with a maximum aggregate size not exceeding 2mm, troweled smooth according to the designed slope. Depending on the weather, humidity, and air temperature… After completing the final mortar topping layer for about 4 to 6 hours, surface polishing can be carried out by evenly spreading a layer of cement powder or a thin layer of cement slurry on the polished surface.

3.2.4. The polished surface must ensure the glossiness according to the design. The polishing process is carried out simultaneously with repairing localized dents and scratches on the surface.

3.2.5. The marking work is done immediately after finishing the color application. The marking lines need to be even in width, depth, and sharpness. If using a roller with anti-slip particles, it is also rolled immediately when the colored cement layer is not yet hardened.

3.2.6. For long sidewalks or long walkways, every 3-4m segment, an expansion joint is made in the topping layer by cutting across the topping layer. The width of the expansion joint is 20mm and is filled with bitumen No. 3.

3.2.7. For areas and zones with high waterproofing requirements such as toilets, water tanks, water gutters and drains… in addition to normal plastering and topping, waterproofing layers must be implemented according to the design beforehand.

3.2.8. The quality of the topping surface must ensure the requirements of flatness, slope, and other requirements similar to those for the plastered surface.

4. Cladding works

4.1. Protective and decorative cladding works can be carried out before assembling the structure and depend on the characteristics of the cladding material, the technological process of structural fabrication, and the work sequence specified in the construction design of the project.

4.2. For brick-built works and brick, ceramic, or natural stone cladding materials, the cladding of the work surface can be done simultaneously with the wall construction.

4.3. For prefabricated structures manufactured in factories, the cladding work is done right during the casting of the structure.

4.4. When cladding the exterior and interior of the work with wood, ceramic, porcelain, natural or artificial stone, synthetic plastic sheets… it is usually carried out after the structural installation work has been completed.

4.5. The surface of the structure to be decoratively cladded or protectively cladded in the vertical direction must not have a deviation exceeding the allowable value specified for reinforced concrete and masonry structures.

4.6. Before carrying out the cladding of the interior and exterior surfaces of the work, it is necessary to complete the related work to avoid impacts that damage or affect the quality of the cladding surface.

4.7. Before cladding concrete or masonry surfaces with glazed tiles or natural stone slabs, a grid for positioning must be drawn on the base surface.

If the cladding surface has a decorative pattern, each cell must determine the coordinates corresponding to the details of the pattern according to the design. The cell dimensions depend on the complexity of the pattern.

4.8. When cladding large-sized sheets, mechanical means must be used. The scaffolding system for construction must be very solid and not affect the operation of the equipment during cladding.

4.9. For material slabs and products weighing more than 50kg, when moving to the cladding surface position, they should not be handled manually but rather use mechanical or semi-mechanical conveyance means.

4.10. Natural or artificial cladding materials, when brought to the site, must be packaged according to the correct specifications, with labels clearly stating the dimensions, weight, type, color…

4.11. To ensure good adhesion between the cladding sheet and the structure, the back of the cladding sheet must be cleaned. Before cladding, the cladding surface must be roughened (or quickly spread with water), and then the bonding mortar layer is applied.

4.12. For natural stone cladding details, during construction, adjacent slabs must be selected and arranged to match in color, gloss, and harmonize in veins, according to the instructions of the design architect.

4.13. When cladding natural or artificial stone slabs with large dimensions and weighing over 5kg, the fastening to the structure must use metal hooks or adjustable bolts and screws. The mortar joint dimensions are determined by wooden strips and pads. The gap between the structure and the cladding sheet is filled with cement-sand mortar. The joints between the sheets must be filled with cement mortar.

4.14. When cladding large-area structures, the positioning of the cladding sheets must be based on the load-bearing structure. On the steel frame, there are hooks or connecting and adjusting bolts for each cladding sheet. The filling of mortar into the gap between the structure and the cladding sheet must be done immediately with each cladding row.

4.15. When cladding the interior of the work with wood sheets or wood slats, a wooden frame base must be arranged to serve as a connecting and positioning frame for the cladding surface. This frame system is closely connected to the reinforced concrete or masonry load-bearing structure through pre-embedded details. The cladding slats and sheets can be fixed with nails or wood screws.

4.16. Before cladding, the flatness of the cladding surface must be checked. If the cladding surface has unevenness greater than 15mm, it needs to be flattened with cement mortar. In case of using mastic as the bonding material (for glass sheets, synthetic plastic sheets), a 1m ruler must be used to check, at which point the gap between the ruler and the cladding surface must not exceed 3mm.

4.17. Before attaching the cladding sheets to the outside of technical pipelines such as ventilation ducts, vents, chimneys, channels for cooling equipment, and in places with frequent temperature changes, a layer of steel mesh must be wrapped around the cladding surface of the structure.

The wrapped mesh section must suitably extend beyond the technical pipeline area by at least 15cm. Other special structural details need to be mentioned and have specific instructions in the construction drawings.

4.18. The mortar used for cladding works must not use cement with a grade lower than 30N/mm2. To ensure the quality of the cladding mortar in terms of strength and working time, the cement mortar must have a low water/cement ratio and use additional plasticizing additives.

4.19. The plasticity of cement-sand mortar for cladding works must reach 5-6cm.

For cement-sand mortar used to lay natural stone slabs, it needs to have a slump of 6-8cm. Mortar used to fill joints and gaps between the structure and cladding sheets needs to have a slump of 8-10cm.

4.20. When carrying out cladding works, it is necessary to maintain the mortar and its adhesion throughout the cladding process.

The mixed cement mortar needs to be used immediately within one hour. In case the mortar is prepared elsewhere and brought to the site, it must be re-mixed before use and must achieve the necessary plasticity.

4.21. When building brick enclosure walls, if cladding with glazed tiles or ceramic tiles, attention must be paid to the difference in load transfer to the structure and the cladding part. The stone and cladding joints are not the same in terms of shrinkage deformation of the mortar. The horizontal cladding joints need to be fully filled with mortar right during the cladding and masonry process, within the allowable wall height range not exceeding 10m.

In case the cladding wall height exceeds 10m, the lower mortar joints must be left incomplete until the load transferred from the work to the wall reaches 85%, at which point those joints are fully filled with mortar.

The vertical joints of the cladding are fully filled with mortar right during the construction process.

4.22. The flatness of the finished cladding surface must not deviate beyond the values given in Table 4.

4.23. When a part or the entire surface of the structure is finished cladding, dirt stains and mortar on the cladding surface must be cleaned. The cleaning of the cladding surface should only be carried out after the joint bonding mortar has hardened to avoid joint detachment during the cleaning process.

4.24. To avoid the phenomenon of rainwater staining the joints, the edge ribs of roof details, cornice lines, etc. must have a slope directed outward from the work.

4.25. Immediately after completing the cladding work, in addition to cleaning the work surface, other finishing works directly related to the quality of the cladding surface such as grinding, polishing, etc. must be carried out.

4.26. Defects on the cladding surface can be repaired by applying mastic or cement mortar, and the mortar color needs to be mixed to match the color of the cladding base.

4.27. The cladding of interior walls with glazed ceramic tiles, ceramic tiles, porcelain tiles, glass tiles, plastic sheets, various stone sheets, etc. is allowed to be carried out after the load transferred from the work to the wall reaches 65% of the design load.

4.28. When attaching cladding sheets such as glazed ceramic tiles, glass tiles, porcelain tiles, etc. with cement-sand mortar, a thin layer of mortar is applied on the plastered structure, while the back of the cladding sheet is coated with a mortar layer not exceeding 3mm thick. Next, the sheet is cladded onto the structure by pressing or lightly tapping by hand to bring the cladding sheet to the position that has been positioned according to the pre-drawn grid.

4.29. When using mastic to attach porcelain, glass, or synthetic plastic cladding sheets, the structural surface must be flattened. The surface of the colored plaster layer must not be smoothed but rather scored into a diamond grid pattern. The spacing between the scored faces must not exceed 5cm and not be larger than the size of the cladding sheet. The thickness of the mastic layer for attaching the cladding sheet must not exceed 3mm.

4.30. The thickness of the mortar layer for attaching porcelain tiles and similar cladding sheets must not be greater than 15cm and not less than 7mm.

4.31. When cladding the interior surface of the work with natural stone sheets, if the sheet length is less than 10mm, it only needs to be attached with cement-sand mortar having a slump of 9 to 10cm. The cladding is done in horizontal rows. If the sheet thickness is greater than 10cm, metal sheet support hooks need to be arranged.

4.32. Before cladding the work surface, the roofing work and waterproofing work for the enclosure structures above the cladding area must be completed, as well as the installation of window and door frames and other works in hidden places after the wall surface has been cladded. The cladding work must be fully completed before proceeding with color topping.

4.33. After completion of construction, the cladding surface must meet the following requirements:

– The overall cladding surface must ensure the correct geometric shape and dimensions.

– The cladding materials (tiles, various sheets) must have the correct specifications in terms of size and color, not warped, chipped, and the size of defects on the cladding surface must not exceed the allowable values in the standards or design specifications.

– The cladding patterns and decorative lines on the cladding surface must follow the design.

– The color of the cladding surface with artificial materials must be uniform. The cladding surface with natural materials must also be uniform, and the sheets are arranged to harmonize in color and veins.

– The horizontal and vertical mortar joints must be sharp, straight, even, and filled with mortar.

The bedding mortar between the structure and the cladding sheet must be solid. When tapping on the cladding surface, there must be no hollow sound. Hollow tiles must be re-cladded.

– There must be no cracks, paint or lime stains, mortar stains on the cladding surface, and cracks at the corners of the cladding sheets must not exceed 1mm.

– When checking with a 2m long ruler placed against the cladding surface, the gap between the ruler and the cladding surface must not exceed 2mm.

– The allowable error values for the cladding surface during work acceptance inspection are given in Table 4.

5. Embossing works

5.1. Embossed products and details manufactured and brought to the site for attaching to the work must be in a complete state, without requiring further processing.

The surface of the embossed products and details must not have defects, creases, cracks, mortar lumps, or roughness. The shapes and lines must be sharp.

5.2. To decorate the exterior surface of the work, embossed products are usually made from cement mortar.

In special cases, embossed details can be made from gypsum, in which case there must be measures to cover and protect them from the effects of rainwater.

5.3. To decorate the interior surface of the work, embossed details can be made from cement mortar, gypsum mortar, lime mortar, or ground paper pulp. If the indoor humidity exceeds 60%, embossed details made from gypsum must not be used.

5.4. Before attaching embossed details, the construction of the pedestal and attachment base must be completed. The positions of the embossed details must be checked according to the design and marked on the attachment surface of the work or pre-processed for the mounting details of the embossed products.

5.5. The quality of the attachment surface of the embossed product must satisfy the same requirements as for the plastering work.

5.6. The attachment of embossed details must be carried out according to the design and meet the following requirements:

a) Details made from paper pulp mortar are attached with mastic.

b) Small and lightweight details weighing less than 1 kg, made from gypsum mortar, and with a height less than 10cm are attached with cement mortar; if the height is less than 10cm, they are attached with gypsum mortar or cement mortar.

c) Details with an average weight from 1 kg to 5 kg, made from gypsum, with a height not exceeding 10cm are attached with cement mortar; if the height is less than 5cm, they are attached with cement mortar or gypsum mortar combined with hook nails, positioning bolts.

d) For details weighing over 5 kg and manufactured with reinforcement, when attaching the product to the work, it is necessary to connect the reinforcement of the detail with the load-bearing structure of the work.

e) Steel connecting details need to be protected with anti-rust paint or zinc plating.

f) Embossed decorative shapes on the main facade of brick-built works need to be attached to the work simultaneously with the wall construction.

g) It is not allowed to attach details made from gypsum with mastic onto the work surface where the base layer is cement.

5.7. When accepting embossing works, the following requirements must be met:

a) The positional deviation of the details compared to the design must not exceed 1mm over a length of 1m of wall or embossed edge.

b) The deviation of the axis of individual upright details compared to the designed position must not exceed 10mm.

c) The details of a shape must be in the same plane determined by the designed position.

d) The joint lines of the details must not affect the continuity of the lines and create embossed shapes on the work surface.

Table 4 – Allowable errors of cladding surfaces with natural and artificial stone materials (mm)

6. Glass works

6.1. Window frames, door frames, and other structures, before installing glass, need to have primer painting and mastic applied to defective and localized dented areas. The rebates for glass installation need to have the paint cleaned and dried.

6.2. The type of glass and glass fixing trim details must satisfy the design requirements, and steel details must be painted with anti-rust paint. Moving parts (such as hinges, latches, various locks, etc.) must not rub against the glass and the glass frame structure.

6.3. The glass installation mastic must have sufficient plasticity, allowing the glass to be inserted and sealing the gaps between the glass and the frame. After installation into the frame position, the mastic surface must not have cracks. When inserting the mastic, it is not necessary to press hard. The plasticity and fineness of the mastic must allow easy smoothing and create a continuous, non-bumpy joint line that does not stick to the glass or frame and does not slide on the structural surface when smoothing.

When checking the plasticity of the mastic with a 0.5mm thick spread layer on a metal plate, it must not be less than 20mm. The oil mixed with the mastic must be selected to match the quality of the mastic used. The quality of the glass installation mastic needs to be tested in the laboratory.

The manufactured mastic must ensure product quality according to specified standards.

6.4. Glass installation mastic for use in the work must be tightly packaged and have the label of the manufacturing place.

6.5. Glass products brought to the work must be pre-processed according to the ordered dimensions or the design. Along with the glass products, there must be various pads, trims, and positioning nails. Glass cutting must be done by specialized glass cutters. After cutting, the glass products must be packaged by size and arranged into sets for each room, each apartment, or one work.

6.6. The glass must be inserted deep into the frame rebate by a depth equal to 3/4 of the rebate width. Between the glass surface and the sides of the glass rebate, there must be a gap of at least 2mm for inserting mastic. The mastic layer for filling the above-mentioned gaps must be continuous without interruption, smoothed flat, and without bumps or dents.

6.7. Various types of flat glass, decorative patterned glass, frosted glass, wired glass… In addition to the design requirements, they need to be firmly positioned with details suitable for the material and structure of the glass frame such as:

a) Wooden frame – glass is positioned with nails, the spacing between nails must not exceed 300mm.

On each glass edge, there must be at least 2 positioning nails.

If using steel trims, there must be rubber pads between the glass and the trim, and positioning screws are used at a 45° angle to the glass plane.

b) Steel frame – aluminum alloy frame – glass is positioned with rubber pads with zinc-plated steel trims.

The connection between the trim and the frame is made with screws fastened into pre-processed holes. For some types of steel frames or aluminum alloy frames, shaped trims with accompanying rubber pads can be used for positioning the glass.

c) Plastic frame – glass is positioned with plastic trims with screws and mastic attached on both sides.

d) Reinforced concrete frame – glass is positioned with steel rib details embedded in the concrete and steel trims with plastic or rubber pads.

6.9. In residential buildings and other civil works, it is not allowed to install glass with joints (within a glass panel), glass with cracks longer than 10mm, stains that cannot be washed off, glass with foreign objects and other defects…

In case the installed glass panel has joints, it must be agreed upon with the work’s design staff. In that case, a glass panel can be joined with two pieces and overlapped by 20mm. Both sides of the joined glass piece must be firmly positioned with trims with at least 2 screws or nails, and then the joint is filled with mastic on both sides.

6.10. Glass installed in frames belonging to the enclosure structure that takes light from the outside, in addition to ensuring firm positioning and tight connection between the glass and the frame, must also ensure that water does not flow or seep through the joints between the glass and the frame. Steel connecting details must have anti-rust measures with paint or zinc plating. The mastic used must be able to withstand the effects of frequent rain and sun.

6.11. Multi-layer glass installed in wooden frames, steel frames, or reinforced concrete frames must also be firmly fixed with rubber pads, plastic pads with steel trims, or with screws and mastic.

6.12. In works with glass frame structures and skylights, if thermal changes occur during use, the heat-absorbing glass arranged in the frame must be in a free state. Therefore, to position the glass, it is necessary to choose a type of mastic with high plasticity throughout the service life. For glass frames with dimensions exceeding 150 x 80cm, rubber pads must be used.

6.13. High-strength glass used in structures such as elevator shafts, staircases, balconies… needs to be firmly positioned with bolts. At the positions of glass trims in steel or wooden frames, there must be pads made of plastic or elastic rubber.

6.14. The movement and installation of glass with dimensions larger than 1 x 1.5m, as well as the installation of components with pre-installed glass, must be done gently and carefully by hand or with air-pumped equipment. When working with glass, it is particularly important to comply with occupational safety regulations. In case of necessity, the mastic plastering work must have pumping equipment, and the nailing work is done with a specialized nail gun.

6.15. In the winter, the glass installation work for rooms with heating equipment, if the air temperature is below 10°C, is only allowed for fixed frames or structures that cannot be disassembled (such as skylights, glass frames for taking light, decorative window frames, etc.). In this case, the glass installation mastic must be heated to a temperature of +20°C.

6.16. The acceptance of glass works can only be carried out after the glass positioning work has been completed, the mastic has dried, and the glass frame has been painted.

6.17. When accepting glass works, the following requirements must be met:

a) The rebate for glass installation must ensure the dimensions according to the design.

b) The quality of the mastic joint must be flat, smooth, without cracks, without detachment from the glass, and without gaps. In case it is necessary to check the quality of the mastic joint, the mastic joint must be solid and free of defects.

c) The edge line of the mastic joint in contact with the glass must be straight, parallel to the rebate edge. On the glass surface of the joint, there should be no loose or detached mastic debris.

d) The screw caps or nails must be pressed against the glass trim surface and must not protrude beyond the frame surface or be recessed deep into the frame. The connection between the screws and the frame must be firm. The rubber or plastic pads must be pressed tightly against the glass and the edges of the window frame.

e) The rubber pads must be pressed tightly and hold the glass firmly on the inside, while on the outside, the pads are pressed tightly into the frame rebate, and there must be no gap between the pads and the window frame.

f) On the glass surface after installation, there must be no cracks, scratches, or other defects.

g) On the structure as well as on the glass surface after installation, it must be cleaned, with no stains of mud, mastic, paint, mortar, or oil and grease stains.

7. Installation of suspended ceilings

7.1. Before installing suspended ceilings, all other finishing works inside the building must be completed, except for painting and decorative lamination works.

7.2. Suspended ceilings made of decorative panels or panels that combine both decoration and sound absorption need to be firmly connected to the load-bearing structure of the building.

Ceiling beams made of steel or wood must be firmly connected to the suspended ceiling panels with hooks according to the design.

7.3. The position of the suspended ceiling is determined by the frame and ceiling beam system. The position of the frame and ceiling beams must be ensured to be accurate by adjusting the length of the vertical suspension hooks.

The load-bearing components of the suspended ceiling, including the suspension hooks, must be painted with anti-rust paint. For wooden members, they must be treated against termites and wood borers.

7.4. In a room, the installed suspended ceiling panels must have the same dimensions, including length, width, and thickness. The panels must have the same color. The panel surfaces must be flat, without cracks, breaks, chipped corners, stains, etc. The panel dimensions must be checked using standard templates.

For non-standard ceiling panels, the deviation must not exceed the values specified in the design.

Before installation, the ceiling panels must be pre-cut and processed for connecting details or pre-drilled for screw and bolt holes, as well as pre-processed for positions of ventilation grilles and lighting fixtures. Those cutout positions must be protected with paint before installation.

7.5. When starting the suspended ceiling construction, the height of the bottom surface of the ceiling must be marked on the walls and columns. On the walls, studs must be installed corresponding to the positions of the ceiling edge panels adjacent to the walls.

7.6. For ceilings with interlocking grooves, it is recommended to install pairs of adjacent panels, using dowels to prevent slippage between the panels. The joint lines between adjacent panels must be straight.

The width of the joints between ceiling panels must follow the design.

7.7. When installing suspended ceiling panels onto a wooden frame, holes must be pre-drilled for screws or bolts. In case of necessity, steel ceiling panels must be pre-processed with overlapping groove edges and tightly connected using screws or capped nails.

7.8. The sequence of panel installation should be carried out from the center of the room towards the walls. The size and number of screws are determined according to the design and depend on the panel size.

When the ceiling area does not allow full coverage with a whole number of panels, it must be divided so that the ceiling panels are symmetrical.

The last installed ceiling panel is firmly connected with strips inserted through pre-made grooves.

7.9. Checking the flatness of the suspended ceiling must be done in both longitudinal and transverse directions of the room, ensuring levelness in all directions. If the design requires the ceiling panels to have a sound-reflecting slope, tools must be made to check the slope angles, with one edge being horizontal and attached with a water level.

The allowable error in the vertical direction compared to the designed height when installing the suspended ceiling is ±2mm. The deviation within each row of panels compared to the joint axis must not exceed 1mm. The width of the panel joints must follow the design. The joints and dimensions must be even and flat.

7.10 The panel openings for the arrangement of lighting systems or ventilation grilles must ensure the correct positions and dimensions according to the design.

8. Surface coating works.

8.1. Surface coating works include lime solution, cement-lime, and various oil paints. For structures or works with special requirements for the quality of painting works, they will be carried out according to separate instructions or design instructions.

8.2. Before proceeding with painting or lime coating of interior and exterior surfaces of the work, the following tasks must be completed:

– Completion of roofing, eaves, balconies, loggias, railings, floors, waterproofing layers, technical equipment systems in the building such as water supply and drainage pipes, ventilation ducts, telephone and lighting wiring, embedded items…

– Completion of window and door installation.

– Completion of plastering, tiling, cladding, glass installation, ceiling installation and plastering, fire escape stair installation…

– Inspection and repair of defects on the surfaces of structures that need painting or lime coating.

8.3. In case of repainting or lime coating of old works for maintenance or renovation, the old lime layer must be scraped and cleaned, and uneven or defective areas must be flattened with plaster.

8.4. It is not allowed to carry out exterior painting works during rainy weather and when the structure is still wet, or when the wind speed is greater than 10m/s. The color of lime paint on the exterior of the work must be durable, resistant to weather changes, and not fade.

8.5. The design needs to specify the locations that require painting or lime coating and the specific colors. When there are no instructions in the design, the selection of paint, lime, and colors is agreed upon between Party A and Party B according to available samples or similar works.

8.6. Depending on the solvent, the pigment powder must be completely dissolved in the correct proportions. The pigment powder must not change color when dissolved in the solvent.

8.7. All types of pigment powders, color solutions, paint thinners, lime, various paints, as well as other paint semi-finished products (including lime paint, synthetic paint…) must be carefully packaged and accompanied by labels and usage instructions. When the packaging is damaged, the label is lost, and there are doubts about the quality, they need to be tested before use to determine the plasticity, adhesion, viscosity, and other properties of the paint.

8.8. All types of lime paint and cement-lime paint must be filtered through standard mesh screens before applying to the structure. Specialized equipment should be used to stir and filter the lime solution on-site.

8.9. The use of oil paints, synthetic paints, and paint thinning semi-finished products… must be done according to the correct mixing process and ratios as instructed on the packaging labels or specific instructions for each type of paint.

8.10. The structural surface before painting or lime coating must be cleaned of dust, dirt, oil stains, and mortar stains. Locations with stains that cannot be cleaned can be coated with silicate primer or potassium glass solution (ratio 1/3) mixed with white silicate powder. For high-quality painted wood surfaces, the wood surface must be sanded smooth, and cracks or defective dents must be filled with mastic before sanding. The wood surface must be dry before painting.

8.11. At the junctions between partitions and doors, wall cabinets and load-bearing walls, ceilings, and junctions between structures made of different materials, they need to be sealed with a non-lining type of mastic. In some cases, at the connecting joints, auxiliary strips can be used, freely stapled to the walls so that when the work deforms or settles, any cracks that appear will be covered by the strips.

8.12. Rough surfaces of the structure must be flattened by plastering or applying mastic. Allowable cracks on the structure must be filled with mastic to a depth not greater than 20mm.

Depending on the quality, flatness, and smoothness of the structure to be painted, it can be divided into the following 4 groups:

Group I: Surfaces with standard flatness and smoothness, no processing required before painting;

Group II: Surfaces requiring processing of uneven areas and filling cracks with mastic, accounting for 15% of the painting area;

Group III: Surfaces requiring processing of uneven areas and filling cracks with mastic, accounting for 15% of the painting area;

Group IV: Surfaces requiring 100% of the painting area to be processed by coating uneven areas and cracks with mortar or mastic before painting.

The surface of prefabricated reinforced concrete structures manufactured in factories must have the required flatness and smoothness, without the need for reprocessing before painting.

8.13. When carrying out painting in residential rooms, offices… If the paint mixture is toxic and the emitted toxic fumes are harmful to human health, there must be safety equipment, and only after the paint has dried and the toxic fume emission process has ended, people are allowed to use that room.

8.14. When carrying out painting works, it is necessary to follow the painting process for each layer, the drying time between intermediate paint layers and the final paint layer to ensure the paint drying time, increase the surface gloss, and the adhesion of the paint to the structure. Each subsequent paint layer should only be applied after the previous layer has dried and hardened. The painting sequence for works exposed to corrosive environments is carried out according to separate guidance documents.

8.15. Before painting, it is necessary to determine the moisture content of the structural surface. For concrete, reinforced concrete, and gypsum structures, the moisture content must not exceed 8%; for wood structures – not exceeding 12% when using oil paints. When using lime paints, cement-lime paints, and some other types of synthetic paints, a higher moisture content of the structural surface is allowed and must follow the design instructions.

8.16. Sanitary equipment, various pipelines, stoves, and enclosing structures need to be painted according to the design instructions with anti-rust paints and oil paints. When painting water supply and drainage pipes and heating systems, water and steam must be drained from the piping system. The paint color of technical pipes must follow the design instructions. If the piping system has thermal insulation, it must be painted with anti-rust paint before insulation, and the outer insulation layer must be painted with the specified color. The outermost paint layer of the insulation must ensure waterproofing to prevent water from reducing the effectiveness of the insulation layer.

8.17. When polishing wooden floors with varnish, it must be done with at least 2 layers. Before and after polishing each layer, the floor needs to be cleaned and polished.

8.18. The acceptance of painting works is only carried out after the painted surface has completely dried and hardened.

8.19. The quality of painting works after work acceptance must satisfy the following requirements:

– The painted surface must have a uniform color, without stains, the boundary lines between painted areas must not have paint accumulation, dripping, or clumping. On the structural surface, there must be no uneven spots that affect the color and gloss of the work. Traces or lines created by paint brushes are only allowed for structures with rough painting requirements but must not be clearly visible when viewed from a position 3m away from the painted surface. This case is only allowed for lime-coated or cement-lime-coated surfaces.

– The surface of oil paint, synthetic paint, and varnish must be smooth, glossy, and uniform in color, without allowing the color of the underlying primer layer to show through, and there must be no stains, drips, paint accumulation, or color discontinuity, thickness variations, and brush marks…

– The boundary lines between two painted areas with different colors must be sharp, following the design in terms of color, position, and pattern. The allowable deviation in dimensions must not exceed 5mm for rough painting; 2mm – for high-quality painting.

– The color border lines, window frame border lines, or decorative patterns must have the same width and color throughout the length, without interruptions, and the breaks and unevenness must not be clearly visible.

– When painting using spray painting or patterned roller painting methods to create decorative patterns, they must create shapes that are uniform in color and size, without allowing pattern interruptions, stains, and drips from the roller at the junctions or joints between structures.