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Preventing and controlling common project quality problems is an important measure to effectively improve the quality of residential projects and safeguard public interests, so as to achieve practical results. According to the requirements of the "Measures for the Prevention and Control of Common Quality Problems in Residential Projects in Yangzhou" and the "Prevention and Control Plan and Construction Measures for Common Quality Problems in Projects" prepared by the construction unit, and the task book for the prevention and control of common quality problems issued by the construction unit, the following supervision details are prepared based on the characteristics of this project.: 1. Anti-cracking measures for walls (1) During masonry construction, ring beams, structural columns, door and window lintels, wall beams and tie bars must be set up strictly in accordance with the design and specification requirements. ； (2) Arrange the arrangement of hollow bricks according to the locations of water, electricity, pipe fittings and wire boxes. (3) The hollow bricks that have been laid must not be pried at will. If the bricks are moved loose after being laid, the original mortar must be eradicated and rebuilt. (4) Strict quality requirements for the external dimensions of the hollow bricks themselves. Try to improve the craftsmanship of the masonry as much as possible. (5) Use medium-coarse sand for masonry mortar. (6) When the infill wall is built close to the bottom of the beam or slab, a certain gap should be left. After the infill wall is completed and spaced 15 days apart, it can be patched up tightly. ； When repairing, the vertical joints on both sides should be filled tightly with high-grade cement mortar. (7) The full-length cast-in-place reinforced concrete slab should be poured in one go. (8) The spacing between the tie bars of the frame-filled wall should meet the brick (block) module requirements and must not be bent or pressed into the mortar joints. 2. Measures to prevent cracking of cast-in-place slabs (1) The concrete of cast-in-situ slabs should use medium-coarse sand. (2) Concrete should use admixtures with high water reduction rates, good dispersion properties, and small effects on concrete shrinkage. The water reduction rate should be no less than 8%. (3) The sand content of ready-mixed concrete should be controlled within 40%, the amount of coarse aggregate per cubic meter should not be less than 1,000kg, and the amount of fly ash should not be greater than 15%. (4) A concrete slump bucket must be available on site, and the mold slump of ready-mixed concrete must be checked truck by truck when it enters the site. (5) During concrete pouring construction, reliable measures should be taken to control the thickness of the cast-in-place slab and the position of the steel bars in the cast-in-place slab, especially the position of the negative bending moment in the upper layer. (6) The wire pipes in the cast-in-place slab must be arranged on the steel mesh (for double-layer two-way reinforcement, they are arranged between the upper and lower steel bars). Wire boxes should be used at cross wiring locations. The diameter of the wire pipes should be less than 1/3 of the floor thickness. A φ6@150 steel mesh belt with a width of not less than 450mm should be added along the direction of the embedded pipeline. It is strictly prohibited to bury water pipes horizontally in cast-in-place slabs. (7) When pouring the cast-in-place slab, two vibrations should be carried out before the initial setting of the concrete, and two pressure troweling should be carried out before the final setting of the concrete. (8) When pouring the cast-in-place slab, it should be covered and watered for curing within 12 hours, and the curing time should not be less than 7 days. ； For concrete mixed with retarding admixtures, the duration shall not be less than 14 days. (9) During the curing period of the cast-in-place slab, when the concrete strength is less than 1.2Mpa, subsequent construction is not allowed. When the concrete strength is less than 10Mpa, heavy objects shall not be lifted, transported or stacked on the cast-in-place slab. When lifting and stacking heavy objects, the impact on the cast-in-place slab should be reduced. (10) The bottom of the cast-in-place slab should be painted-free. (11) In addition to meeting the strength requirements, the selection of formwork and supports must also have sufficient stiffness and stability. The distance between the side support poles and the wall should not be greater than 300mm, and the distance between the side support poles and the wall should not be greater than 300mm, and the middle should not be greater than 800mm. According to the construction period requirements, a sufficient number of formwork will be equipped to ensure that the formwork is removed according to the specifications. 3. Anti-leakage measures on the floor (1) Leakage in bathrooms is a common problem. We will pay attention to it and strive to overcome it during the construction process. First, each room will be tested for water content after the reinforced concrete construction. After the construction of the hanging formwork and waterproof mortar surface layer of the bathroom pipes is completed, a water content test will be conducted for each room. If problems are found, records will be made and they will be dealt with in a timely manner. (2) Cast-in-place concrete and beams with a height of 200mm should be installed at the bottom of the bathroom infill wall (except door openings). (3) The coordinates of the reserved openings for water pipes and other pipes should be correct, and the shape of the openings should be larger at the top and smaller at the bottom. (4) Before pipe installation, the smooth outer walls of the upper and lower water pipes within the thickness of the floor slab should be roughened first, then evenly coated with a layer of 401 plastic glue, and then sprayed evenly with screened medium-coarse sand. (5) Before filling the reserved holes in the cast-in-place slab, the holes should be cleaned, textured, and glued cement slurry should be applied as a bonding layer. The hole filling is poured in two steps. First, micro-expanded fine stone concrete mixed with anti-crack and anti-seepage agent is poured to 2/3 of the thickness of the floor. After the concrete solidifies, a 4-hour water storage test is performed. ； After there is no leakage, it is filled with cement mortar mixed with anti-cracking and anti-seepage agent. After the pipeline is installed, a 24-hour water storage test should be conducted at the entrance of the hole. (6) Before the construction of the waterproof layer, the surroundings of the floor should be cleaned and the inner corners should be powdered into small arcs. The flashing height of the waterproof layer shall not be less than 300mm. (7) The ground leveling layer should be sloped 1-1.5% toward the floor drain, and the floor drain opening should be 5mm lower than the adjacent ground. (8) After the ground construction with waterproof requirements is completed, a 24-hour water storage test should be carried out, and the water storage height should be 20-30mm. 4. Anti-cracking measures for exterior wall painting (1) Strengthen the surface treatment of the plaster base, remove dirt from the base of the wall and clean it up. Holes left during wall construction and hollow brick wall joints must be plugged and filled. (2) Strictly control the thickness of plastering, try to ensure uniform thickness, and apply plastering in layers. (3) If the beams or columns protrude from the wall, plaster the wall first, then plaster the surface of the beams and columns after the plastering on the wall is dry, and make the surface plaster of the beams and columns press against the plaster layer on the wall so that the shrinkage cracks at the joints are covered by the plaster layer behind the beams and columns. (4) Try to improve the wall plastering technology and strengthen the treatment of weak parts. (5) After the plaster is formed, pay attention to the protection of the finished product and strengthen the maintenance of the plaster layer in a timely manner. (6) Medium-coarse sand with a mud content of less than 2% and a fineness modulus of not less than 2.3 should be used for exterior wall painting. It is strictly prohibited to use stone powder and mixed powder. (7) Expired cement must not be used in plastering projects, and its setting time and safety must be qualified. (8) The holes in the external wall should be left in accordance with the specifications, and they should be blocked twice with half bricks and waterproof mortar, and the surface should be 1: 3. The waterproof mortar must be powdered tightly, and small round holes should be filled and compacted twice with micro-expansion cement mortar. A dedicated person should be responsible for filling holes, and special concealed acceptance procedures should be completed in a timely manner. (9) The base layer of the stucco concrete structure of the exterior wall should be textured with an interface agent and maintained by water spraying. When the flatness deviation of the base layer exceeds the standard, local chiseling should be carried out (no steel bars should be exposed during chisel removal), and then polymer cement mortar should be used for repair. (10) Exterior painting must be done with grid joints according to the design requirements of the drawings. (11) The thickness of exterior wall paint leveling putty should not be greater than 1mm. (12) The drainage slope painted on awnings, overhangs, etc. should not be less than 2%. The paint on the drip line should be dense and straight, and there should be no water creeping or poor drainage. 5. Wind resistance and anti-seepage measures for doors and windows (1) Witness sampling testing of three properties should be carried out before the doors and windows are installed. (2) Before installing and fixing door and window frames, the size of the wall hole should be reserved for review, roughened with waterproof mortar, and then the outer frame should be fixed. The gap between the fixed outer frame and the wall should be determined according to the facing material. (3) Doors and windows should be installed and fixed using galvanized iron sheets. The thickness of the galvanized iron sheets should not be less than 1.5mm, and the spacing between fixed points should be: 180mm at the corner and no more than 500mm at the edge of the frame. It is strictly forbidden to use long expansion bolts to penetrate profiles to fix door and window frames. (4) The door and window openings should be clean and dry before applying the foaming agent. The foaming agent should be continuously applied, formed at once, and fully filled. The foaming agent that overflows outside the door and window frames should be stuffed into the gap before conjunctiva to prevent damage to the outer film of the foaming agent. (5) A 5mm wide glue slot should be left on the outside of the door and window frames. (6) The sealing surface should be clean and dry before applying sealant, and neutral silicone sealant should be used. It is strictly prohibited to apply sealant on the paint surface. 6. Roof anti-leakage measures (1) Before the construction of the roof project, a detailed construction plan must be prepared, and the construction can be organized only after being reviewed and confirmed by the supervisor. (2) Flexible waterproof materials should be used for flashing on pipes extending out of the roof and structures higher than the roof, with a height of not less than 250mm (pipe flashing not less than 300mm) ； The last flashing material should be rolled material, and the top of the rolled material should be pressed tightly with pipe hoops or pressure strips, and then sealed with sealing material. (3) After the construction of the roof waterproof layer is completed, a water storage or water spray test should be carried out. 7. Control of indoor elevation and geometric dimensions (1) Strictly control the thickness of cast-in-place concrete slabs. Cast-in-place concrete slabs are important components of concrete structural projects. In recent years, due to lax quality control in a few projects, the thickness of cast-in-place concrete slabs has been lower than the designed thickness, resulting in serious deviations, which has caused adverse effects on society. In order to prevent similar problems from occurring, our construction unit strictly controls the thickness of cast-in-place slabs in concrete structure projects. a. Perform "dual control" on the thickness and flatness of the cast-in-place concrete slab. Use concrete prefabricated blocks that are 5mm thinner than the slab and have a higher strength level. The thickness of the cast-in-place slab shall be rigidly controlled by no less than 5 blocks per room. b. During the concrete pouring process, strengthen the self-inspection of the concrete slab thickness to solve the problem before the final setting of the concrete, so that the process control can be truly implemented. (2) Measurements must be carried out by dedicated personnel, and various measuring instruments should be calibrated regularly. (3) During the main construction stage, the control lines of elevation and axis (such as the 1m line on the wall, the square control line on the ground, etc.) should be popped up in a timely manner, measured accurately, recorded carefully, and the on-site control lines should be clearly marked. (4) Strictly control the thickness of the cast-in-place slab. Before concrete pouring, a control mark for the thickness of the cast-in-place slab should be placed. One mark should be set up every 1.5-2m2. (5) During the decoration stage, construction should be carried out strictly in accordance with the pop-up elevation and axis control lines, and if any excess is found, it will be dealt with in a timely manner. (6) Measure the indoor elevation and axis of the building according to the inspection batch. After the measurement, carefully fill in the "Building Indoor Elevation, Axis, Floor Thickness, and Flatness Measurement Record". (7) The number of inspections of indoor elevation and axis positions. 10% of the number of rooms and no less than 5 in each inspection batch shall be randomly inspected. (8) Inspection of floor slab thickness. Residential buildings are divided into inspection batches by floor. In each inspection batch, the total number of natural rooms shall be ≥10% and no less than 5 slabs shall be randomly inspected. The flatness shall be tested before the natural rooms are randomly inspected.