4.1 construction process

The flat roof with the most construction technology 2 (with insulation) is used for explanation: Figure 4-1

4.2 construction of base course and leveling layer

The treatment of base leveling layer is the same as that of sloping roof, but there is no need to add waterproof agent in the leveling layer, and the mix proportion is 1:2.5 cement mortar, the thinnest part is 20 mm, and 2% slope shall be found towards the design direction of the drawing. The third layer of the slope making layer is the coating waterproof layer, so the quality of the layer should be improved. The flatness of the leveling layer has a great influence on the quality of the coating waterproof layer, reducing the reliability and durability of the coating waterproof layer.

4.3 construction of polyurethane waterproof layer

2 thick polyurethane waterproof coating is adopted for the flat roof of the project.

4.3.1 construction process

Base course surface cleaning → spraying base course treatment agent → additional treatment of special parts → coating waterproof coating and laying carcass reinforcement material → cleaning, inspection and correction → protective layer or next process

4.3.2 before construction, be familiar with the drawings, and master the construction requirements, node practices and relevant technical requirements in the construction drawings. Arrange reasonable construction sequence.Conduct technical disclosure to the construction team.

4.3.3 after the base course is treated, an additional layer of carcass reinforcement material shall be added at gutter, cornice, gutter, roof outlet pipe, chimney, separable joint and other parts, with a width of 300 mm.

4.3.4 before the construction of polyurethane coating, the base treatment agent shall be brushed for one side, the base treatment agent cold primer oil shall be stirred evenly, and the long handle roller brush shall be applied evenly on the base surface, and the construction shall be started after 4 hours at normal temperature.

4.3.5 the construction of membrane waterproof layer shall follow the principle of "first high then low, first far then near". First coating the parts far from the feeding point, and then coating the near parts. For the same roof, first coating the joint parts such as the gutter, gutter, cornice and so on with concentrated drainage, and then coating the large area.

4.3.6 the lap width of the long side of the carcass reinforcement material shall not be less than 50mm, and the lap width of the short side shall not be less than 70mm.

4.3.7 when the roof coating is applied, it is not allowed to step on the layer that has not been solidified, and the waterproof ability of plastering is easy to cause safety accidents on the slide way.

4.3.8 the thickness of waterproof coating shall be strictly controlled, which shall meet the design requirements of 2 thickness, and the inspection thickness shall not be less than 80% of the design thickness.

4.3.9 before the film waterproof layer is dry, other construction operations shall not be carried out, and articles shall not be directly stacked on the film waterproof layer.

4.3.10 after the completion of waterproof coating, the next process construction can only be carried out after rain or water spraying, and visual quality inspection.

4.4 construction of thermal insulation layer

The flat roof of the insulation layer construction adopts the dry laying method, and the insulation board shall be close to the surface of the base layer, paved and padded stably, and the joints shall be filled with chips of similar materials.The inspection and distribution of quality requirements are the same as the construction of sloping roof, but there is no need to lay reinforcement mesh

4.5 concrete waterproof layer

A 40 thick C30 UEA shrinkage compensating concrete waterproof layer is built on the thermal insulation layer, with a two-way middle distance of 150 μ 6 reinforcement. The concrete is commercial concrete. In addition to the precautions for ordinary concrete construction, the following points shall be paid attention to during the construction of shrinkage compensating concrete:

4.5.1 before pouring concrete, all objects in contact with concrete shall be fully wetted.

4.5.2 the shrinkage compensating concrete is easy to produce early plastic shrinkage cracks due to no bleeding, so it is necessary to pay attention to early maintenance.

4.5.3 if the concrete delays in transportation, the slump loss will cause construction difficulties, but it is not allowed to add mixing water to avoid greatly reducing the strength and expansion rate. In order to ensure the proper amount and proper addition of retarder.

4.5.4 considering that the roof construction is the summer and Autumn Festival, and there may be high temperature or rainstorm weather, it is stipulated that when the temperature exceeds 35 ℃, it is not suitable for construction. If construction, cooling measures must be taken.

4.5.5 it is very important to maintain the moisture of the shrinkage compensating concrete after pouring. Curing shall be started immediately after pouring, and the curing time shall not be less than 7d. Water storage, drying and covering can be used for maintenance.

4.5.6 the setting time of shrinkage compensating concrete is short, and the plastering and calendering time shall be carried out in advance, not too late.

4.6 floor tile construction

The floor tiles are 8-10 thick, 25 thick 1:4 dry hard cement mortar, and the surface is paved with plain cement. Precautions for brick laying:

4.6.1 the base course shall be cleaned and wetted with alcohol.

4.6.2 before paving, the specification, size, appearance quality, color, etc. of bricks shall be preselected, soaked and wet, and then dried for use.

4.6.3 dry and hard cement mortar shall be used for paving, and the facing brick shall be tight, solid and full, and the elevation shall be strictly controlled.

4.6.4 the gap width of face brick shall meet the design requirements of 5-8mm.

4.6.5 the joint wiping, pointing and pressing work shall be carried out within 24 hours for the paving and pasting of face bricks. The depth of the joint should be 1 / 3 of the thickness of the brick; the cement of the same type, grade and number should be used for joint wiping and pointing, and the cement should be cleaned as soon as it is done, and maintained and protected.