Main points of roof waterproof construction
1. Environmental requirements for construction
In order to ensure the construction operation and the quality of the coiled material, it should be constructed at a temperature of + 50C to + 350C; polymer modified asphalt and polymer waterproof membranes should not be constructed below negative temperature. Constructed at temperatures above -100C, this coil is resistant to low temperatures and is not prone to freeze damage at negative temperatures. Rain, snow, frost, fog, or atmospheric humidity is too high. and windy weather is not suitable for outdoor operations, otherwise appropriate technical measures should be taken.
2. Requirements for roof drainage slope
The drainage slope of the flat roof is 2% to 3%. When the slope is less than or equal to 2%, the material should be used to find the slope; when the slope is greater than 3%, the structure should be used to find the slope. The longitudinal slope of the gutter and eaves shall not be less than 1%, and the drop at the bottom of the ditch shall not exceed 200mm. The slope within 500mm in diameter around the water drop should not be less than 5%.
3. Treatment of gaps and cracks in the roof base
The base layer is prefabricated concrete slab. When the gap width between the slab and the slab is less than 20mm, use fine stone concrete grouting, the particle size of the stone should not be greater than 10mm, its strength level should not be less than C20, and use expanded cement or mixed expansion as much as possible The concrete mixed with concrete is grouted; when the width of the gap between the slab and the slab is greater than 40mm, 1 ф6 steel bar or steel bar configured according to the design requirements should be set in the slab seam. After the slab concrete is poured, it should be covered and watered in time. Now, when the concrete strength level reaches C15, construction can continue. To prevent the grouting concrete from being subjected to the construction load prematurely, and to ensure the bonding strength between the slabs.
When the base layer is cast-in-place reinforced concrete, when there are cracks in the board, the cracks should be chiseled into a slot of 15-20mm wide and deep in the shape of a figure eight, and then the stone slag is cleared away, the trench is blown clean, use Fill the cracks in two to three times to fill the cracks, each time interval must be 15 minutes long, after filling the cracks, use a roller to flatten.
4. Requirements for roof leveling
The leveling layer is the base layer of the waterproof layer of the coiled material, which provides a flat, dense, strong, and bondable structural foundation for the waterproof membrane. Therefore, the leveling layer of the coiled material should be solid, and there should be no protruding sharp corners, pits or sand on the surface. When checking with a 2 meter ruler, the gap between the ruler and the leveling layer surface should not exceed 5mm , The gap is only allowed to change gently, and no more than one place per meter length. The corner formed by the adjacent surface of the leveling layer shall be made into an arc or an obtuse angle. When the base layer is integral concrete, cement mortar leveling layer is used, the thickness is 20mm, the ratio of cement to mortar is 1: 2.5 ～ 1: 3 (volume ratio), and the cement grade is not less than 42.5. The leveling layer shall also be provided with lattice joints and embedded with sealing material, so as to avoid or reduce the cracking of the leveling layer, so that when the structure is deformed or the temperature difference is deformed, the waterproof layer will not form cracks, resulting in leakage. The slit width is 20mm, and the vertical and horizontal spacing of the cell slits is not more than 6m. The location of the cell slits is set at the support end of the roof panel, the junction of the waterproof layer and the protruding roof member at the corner of the roof, and the junction of the waterproof layer and the parapet wall Wait. And should be aligned with the end seam of the board, even and straight. During the construction of cement mortar leveling layer, first clean the sundries of roof and floor slabs and spray them with water to moisten them. When laying mortar, follow the procedure from far to near and from high to low, paving continuously in each division, control the slope according to the design, and scrape it with a scraper of more than 2m in length, after the mortar has received a little water, Use trowel to compress and smooth, cover with straw bag after 12 hours, water and conserve. For the detailed nodes such as the structure and pipe roots protruding from the roof, arcs, truncated cones or square truncated cones should be made, and they are made of fine stone concrete to avoid cracking and paving of the coiled material at the joints, which is conducive to stickiness.
1. Water drip: It is made within 500mm around, the slope is ≥5%, and it is smooth.
2. The roots of the parapet wall, the roof flue, and the stairs are made of circular arcs with a radius of 80mm and are made of fine stone concrete.
3. Extend around the root of the roof pipe, and use fine stone concrete to make a truncated cone, the bottom of the cone is 300mm wide and 60mm high, smooth and smooth.
5. Primary treatment agent
In order to strengthen the adhesion between the waterproof coiled material and the base layer and ensure the integrity, before the waterproof layer is constructed, the paint on the base layer is pre-painted. Commonly used base treatment agents include cold base oil and primers (base treatment agents) matched with various polymer modified asphalt coils and synthetic polymer coils. When selecting, they should be compatible with the material of the coil to avoid curling. The material is corroded or the incompatible bond is poorly detached.
Before spraying the cold base oil and the base layer treatment agent, check the drying and cleaning of the leveling layer before coating, and then use the brush to treat the nodes, periphery, corners and other parts of the roof first, and finally spray and brush on a large area. The spraying and brushing should be thin and even, and cannot be white or thick. The cold base oil is applied 1-2 days before application, and the base material is dried for approximately 4 days after application before applying the roll material.
6. Paving of the coiled material
1. The laying direction of the coil: the laying direction of the coil should be determined according to the roof slope and whether there is vibration on the roof. Dangwu
When the slope of the surface is less than 3%, the coiled material should be laid parallel to the ridge; when the slope of the roof is 3% -15%, the coiled material can be laid parallel or perpendicular to the ridge; when the slope of the roof is greater than 15% or subjected to vibration, the asphalt coiled material Paving should be perpendicular to the roof ridge, and other parallel or vertical roof ridges can be considered according to the actual situation. Laying layer by layer from the cornice to the roof, all kinds of coils should be overlapped up and down, the overlapping position of the multi-layer coils should be staggered, and the upper and lower coils should not be laid vertically.
2. The order of affixing the coiled material: when constructing the waterproof layer, the nodes, additional layers and roof drainage concentrated areas (such as the connection between the roof and the water outlet, the cornice, gutter, cornice, roof corner, board end) Seam, etc.), and then proceed upward from the lowest elevation of the roof. When paving gutters and eaves rolls, it is advisable to follow the direction of the gutters and eaves to reduce overlap. When paving roofs with multiple spans and with high and low spans, the order of height first, then low, then farthest, then near should be carried out.
3. Coiling method and width of the coiled material: Laminating method is used for laying the coiled material, and the overlapping seam of the upper and lower layers and the adjacent two coiled materials should be staggered. The lap seam parallel to the roof ridge should be lapped in the direction of the water flow: the lap seam perpendicular to the ridge should be lapped with the prevailing wind direction. Each layer of coiled material should be lapped at the connection between the gutter and the roof, and the lap joint should be staggered; the joint should be left on the side of the roof or gutter, and not on the bottom of the ditch.
For arched roofs with slopes of more than 25% and slopes under skylights, short edge overlaps should be avoided as much as possible. When short edge overlaps are necessary, measures to prevent the coils from sliding should be taken at the overlaps.
Seven, the details of waterproof membrane
The base layer at the intersection of the flooding and the roof should be made obtuse (> 1350) or arc (R = 50 ～ 100mm). The height of the waterproof layer to the vertical surface should not be less than 250mm, often 300mm; In order to prevent water leakage at the entrance, the waterproof cornice of the coil material is divided into several forms: free fall, outer eaves, and gutters in the parapet. (8) Protection of roofing waterproofing membranes After the installation of waterproofing membranes, it must be well protected so as not to affect the waterproofing effect. Lay a 300mm × 300mm expanded perlite insulation block on the waterproof layer, and then add a layer of 3cm thick cement mortar protective layer on top of it. The layer is covered with steel wire mesh, and the protective layer is provided with lattice joints. To better protect the waterproof layer.