* waterproof construction technology
With the development of our country's urban modernization construction, the requirements for roof waterproof performance of buildings are getting higher and higher.A good roof waterproof project not only can effectively prevent leakage, but also has very important significance for protecting the building structure and prolonging the service life of the building.However, judging from the most common construction effects of rigid roof waterproofing and flexible roof waterproofing, the waterproof effect cannot reach the best state.Therefore, how to effectively improve the quality of roof waterproof construction is a major problem in current construction.This article discusses the waterproof construction technology after organically combining rigid waterproof with flexible waterproof by analyzing the requirements for improving the quality of waterproof design and construction, and discusses the methods and measures of this technology as well as the quality control methods, so as to provide reference for the vast number of workers to communicate with each other.
Generally speaking, rigid waterproof refers to the use of rigid materials such as concrete or mortar for roof waterproof construction. such construction technology has the shortcomings of self - importance, poor tensile strength and ductility.While flexible waterproof refers to waterproof construction made of flexible materials such as waterproof coiled material or asphalt felt. this kind of roof flashing layer is easy to age, has poor resistance to external abrasion or puncture, and has short service life.Therefore, if the two types of waterproof technologies can be organically combined to learn from each other and adopt technical measures to effectively avoid their respective defects, the positive effects of rigid waterproof and flexible waterproof can be brought into full play and better roof waterproof effect can be achieved.
1, improve the quality of roof waterproof design
Roof is a very important part of a building structure, which is the main structure of the whole building to realize effective waterproof, sunscreen and heat insulation. therefore, the construction quality of roof engineering is very high in the construction, especially the quality of roof waterproof design and construction, which is also related to the residents' comfort and the length of construction time.Generally speaking, the roof waterproof design should meet the following requirements:
1.1 the roof shall form a continuous completely closed waterproof layer.Only in this way can the building be protected from rainwater invasion caused by external natural or human factors and the internal structure of the building be protected.
1.2 the waterproof layer will not be damaged or cracked due to cracking at the grassroots level and movement of joints.This refers to the fact that concrete is often used in the construction of the main structure in the current construction, and cracks or cracks often occur in the concrete structure. the waterproof design should take this point into consideration and take preventive measures to ensure that the waterproof layer is intact in use.
1.3 the waterproof layer can withstand aging caused by external factors such as weather conditions, such as light, heat, water vapor, ozone, ultraviolet rays and other harmful substances, and can maintain waterproof performance for a long time.
1.4 the deformation of the structure will cause cracking of the waterproof layer. when the settlement of the local foundation is within the allowable range, the integrity of the roof waterproof layer is controlled by the superposition of settlement deformation and temperature difference deformation. the total deformation exceeding the extension limit of the waterproof layer will cause cracking and water leakage. therefore, different foundation and foundation forms should adopt different fortification measures, and the weak strength of the structural rigidity also has a great influence on the waterproof layer.
2, technical methods to ensure the quality of roof waterproof engineering
In view of the fact that the previous waterproof projects used rigid waterproof or flexible waterproof alone, both of them have their own advantages and disadvantages, but on the whole, they still cannot achieve the best effect of building roof waterproof.In this paper, a method of combining these two construction technologies is proposed in order to learn from each other and make the roof waterproof to meet the quality of waterproof requirements to the greatest extent.
2.1 requirements for construction personnel and construction procedures.Waterproofing of roofing works must be carried out by a professional team of waterproofing or waterproofing workers. units without qualification certificates are strictly prohibited to carry out waterproofing of roofing works. construction units or supervision companies should carefully check the work permits of construction personnel.During construction, the construction unit shall carry out quality self - inspection, self-examination and self-correction according to the construction procedures and levels, and make construction records. the supervision unit shall carry out the acceptance of each procedure, and the next procedure and level can be carried out only after the acceptance is qualified.
2.2 technical measures to improve roof rigid waterproof quality.The structural layer of the rigid waterproof roof should be cast-in-situ as a whole. the drainage slope of the flat roof should be 2 % to 3 %. when the slope is 2 %, the material should be selected to find the slope.When the slope is 3 %, the structure should be selected to find the slope.The longitudinal slope of gutter and eaves gutter shall not be less than 1 %, and the gap at the bottom of gutter shall not exceed 200 mm.The slope around the impinges mouth should not be less than 5 % within a diameter range of 500mm, and the downspouts diameter should not be less than 75 mm..When prefabricated reinforced concrete hollow slabs are used, the roof slab shall be grouted with mortar No. 0, C20 fine stone concrete shall be used for serious joint filling, and the concrete for joint filling shall be mixed with micro expansion agent, and each joint shall be grouted tightly twice. when the roof slab joint is wider than 40 mm, structural reinforcement shall be set up in the joint, and the gap at the end of the slab shall be sealed. after initial setting, the joint shall be maintained for 7 days, and the water drain shall be checked for leakage. if leakage is found, l: 2 mortar shall be used for filling.
2.3 technical measures to improve roof flexible waterproof quality.The paving of coiled materials must conform to certain construction procedures. the direction of paving shall meet the following requirements: under normal circumstances, if the roof slope is less than 3 %, paving shall be done parallel to the roof;Roof slopes between 3 % and 15 % can be laid parallel or perpendicular to roof ridges: roof slopes greater than 15 % should be laid perpendicular to roof ridges.Between the upper and lower layers of coil are not allowed to be perpendicular to each other, because after the vertical shop is stuck, the coil is heavily sewed and prone to water leakage.
The long side lap and short side lap of each layer of coil shall not be less than 10 cm: the seam of the upper and lower layers of coil shall be staggered by 1 / 3 of the amplitude;The seams of the two adjacent coils should be staggered by 30 - 50 cm.Perpendicular to the roof of the shop is stuck, each coil should pass over the roof of not less than 20 cm, but it is not allowed to spread a coil from one side of the roof to the other side, so that the shop is easy to break at the roof of the shop.The laying method of coiled material shall meet the following requirements: when the waterproof layer of coiled material is covered with heavy objects or the deformation of the base layer is large, the method of empty laying, point sticking, strip sticking or mechanical fixing shall be preferred, but within 800 mm of the periphery of the roof and between all layers of coiled material laid by lamination shall be fully adhered;Screed-coat is the base of the shop is stuck coiled material waterproof layer, should be solid, can not have prominent sharp corners and pits or surface sand peeling phenomenon, when using 2 meters long ruler to check, the gap between ruler and screed-coat surface shall not exceed 5 mm, the gap only allows gentle changes, and each meter length shall not exceed one place.The corners formed by the adjacent surfaces of the leveling layer should be rounded or obtuse.The drainage slope of leveling layer shall meet the design requirements.
3. quality control measures in waterproof construction
3.1 material selection should be correct.Materials are the basis for ensuring the quality of waterproof engineering. therefore, the selection of materials must be standardized and strict. the selected waterproof materials must have the certificate of inspection by relevant departments. the quality of waterproof materials such as mortar or coiled materials must be checked to prevent inferior waterproof materials from appearing at the construction site.
3.2 close-grained filling joints and holes.For slab joints filled with fine stone concrete, the concrete grade should be one level higher than that of the original concrete. it should be poured in strict accordance with two times of compaction and cannot survive at one time.
3.3 completes the waterproof test.After the completion of the waterproof layer, check whether the edge is tightly sealed, whether there is wrinkle or hollowing, and then carry out water storage test ( water spraying test is required for sloping roof ). if there is any leakage, repair it in time.
3.4 construction quality control of key node parts.Before waterproof construction, the water content of roof concrete should not be too high ( it is to lay 1m2 coil flat and dry on the leveling layer, leave it standing for 3 ~ 4h, and then open and inspect it. no watermark can be found on the covering part of the leveling layer and the coil. the surface should be cleaned up and the floating dust and scum on the surface should be removed. the next working procedure can be started only after the supervision personnel have passed the inspection.
3.5 leveling layer surface should be compacted and leveled.The joints between the base layer and the protruding roof structure, as well as the corners of the base layer, shall be made into circular arcs.The leveling layer shall be reserved with split seams and embedded with flexible waterproof materials.The base treatment agent shall be evenly sprayed;Coil paving shall be carried out according to the principle of " first low, then high, first far, then near", and waterproof treatment shall be done for nodes and parts with relatively concentrated drainage.
3.6 strictly control the waterproofing of detail structures.Gable parapet wall, flashing part, downspout, eaves gutter, roof gutter, pipeline passing through roof and deformation joint are the main parts causing roof leakage. therefore, special attention should be paid to the construction quality control of these points in the construction. the operation methods of construction personnel should be strictly standardized, the construction requirements indicated in the construction design drawings should be effectively implemented, and supervision should be strengthened, especially for the construction quality control of flexible waterproof additional layer.
4. concluding remarks
After the actual construction practice, it is concluded that the waterproof construction technology that combines rigid waterproof with flexible waterproof is feasible and has good waterproof effect, which is worth promoting vigorously.In waterproof construction, we must make clear the design plan, select high-quality materials, strengthen construction management, and do a good job in quality inspection. only when every link of construction is strictly careful can we achieve the best waterproof effect in the overall waterproof construction and meet the needs of contemporary buildings for roof waterproof construction.
（sourcing：net work）
