Pile foundation and box foundation are suitable for high-rise residential buildings, and strip foundation is suitable for low-rise villas and multi-storey apartments. The quality problems we sometimes see, such as wall cracking, floor deformation, roof seepage, etc., may be due to uneven settlement of foundation, which destroys the rigidity of the house. But after the house is built, we can't see the foundation and other reinforced concrete members. We can ask sales, intermediaries and surrounding residents through multiple channels.
2. Look at that wall.
First check whether there is a lime "explosion point" on the wall. This is because the lime has not matured for enough time or there is too much silt in the cement or the mixing is uneven. The "explosion point" can be hit with iron. If it is found that a large area is loose and falls off, it is a quality problem and may bring great inconvenience to life.
Second, the appearance inspection methods to identify the construction quality of the external wall can be divided into several types: the external wall is tiled, mainly to observe whether there is a phenomenon of falling off and unevenness, whether the joints of the tiles are horizontal and vertical, and whether the colors and textures of the tiles are coordinated. If the exterior wall is cement mortar, then apply waterproof coating on the wall, and observe whether the cement mortar falls off or has cracks; At present, fair-faced brick walls are widely used in low-rise villas. This kind of wall has a classical and solemn meaning. Pay attention to whether the jointing of the brick wall is full and whether the brick is dense.
In addition, if the crack is parallel to the beam of the room, it is a quality problem, but it is not a big problem. If the cracks make an oblique angle of 45 to the corner or are perpendicular to the beam, it indicates that there may be structural quality problems in the house. If it is found that there are penetrating cracks in the external wall, then there must be something wrong with the design or construction of the house, and the house quality appraisal department should be asked to re-appraise it.
3. Look at the floor.
Floor slab includes bottom floor slab and floor slab, and the floor slab is first determined as precast slab or cast-in-place slab. The floors of low-rise and multi-storey houses are mainly prefabricated members. It is necessary to observe whether the floor panel is flat and cracked. There are two reasons for cracks: first, the ring beam of the house is uneven, and the seat slurry is uneven when the board is laid; Second, the quality of precast slab is not enough and the bypass is too large; The floors of middle and high-rise buildings are mainly cast-in-place slabs, which have good integrity and waterproofing. Mainly observe whether there are exposed tendons or honeycomb pits. The strength grade of concrete is invisible to the naked eye, so you can see the quality inspection report. If the quality of concrete is too poor, you can dig out the protruding places by hand, such as the corner of the column is a good place to check.
4. Look at the roof.
The main functions of the roof are waterproof, heat preservation and heat insulation. Check the roof drainage slope, drain and gutter organization is reasonable, downspouts should be installed firmly, interface level off, no leakage. In terms of heat insulation, overhead ventilation layer is generally set on the roof, which is beneficial to air flow and heat dissipation.
Pay special attention when looking at the house: water in the gutter, water in the balcony and bathroom floor, water in the balcony after rain, etc. It will cause water leakage on the floor, and even water from horizontal pipes will cause fecal sewage to flow backwards. One inspection method is to do a drainage test in the bathroom and balcony, that is, pour some water here to see if it can be discharged to the water outlet unimpeded.