屋面渗漏的原因及质量控制方法探究

1、 屋面渗漏的原因及质量控制方法探究摘要：建筑的通病“屋面渗漏”尤为普遍，包括：设计、材料、施工、管理维护等四个方面因素，要想做好屋面防水工作，则即要有合理的设计方案，又要合理选择好防水材料，即要按规程精心施工，又要有一整套完整的管理维护措施。关键词：屋面渗漏原因;质量控制;材料选择;施工方法 近几年来，我国建筑行业发展速度很快，但建筑的质量通病屋面渗漏却是多年来一直未能很好解决的难题。不少新建成的工程就出现了渗漏情况，竣工当年就发生渗漏的房屋所占比重很大。老建筑大多采用有机防水，现在也都已到了使用年限，因此其渗漏现象更为严重，然而修补渗漏往往比新建筑防水要困难的多，往往是这儿补好，那儿又漏，一

2、补再补，令用户无法安心居住，形成“年年修，年年漏”的恶性循环。我国每年仅用于屋面防水的维修费用就高达十几亿元。九十年代初，我国建设部曾对全国近100个大中城市的住宅建设渗漏情况进行了随机抽样调查，共抽检了2072栋房屋，建筑面积797.7万平方米，发现屋面渗漏的有725栋，占抽检总数的35%。在调查中发现渗漏的工程中，以采用涂膜防水的渗漏率最高，占涂膜防水工程总数的44.3%,其次是刚性防水和卷材防水，其渗漏率分别为38.7%和31.4%。导致屋面渗漏的主要原因在材料方面占20%22%，设计方面占18%26%，施工方面占45%48%，管理维护占6%15%。由此看来，造成屋面渗漏的因素很多，其中

3、防水施工和材料选用占的比重较大。这就要求我们在施工过程中不但要按要求规范施工，而且要大力推广积极采用防水新技术，新材料，新工艺。在此，就屋面渗漏的原因，谈谈其设计与施工质量控制的几点心得。一、屋面产生渗漏的原因1.结构层混凝土裂缝引起渗漏由温差引起的变形裂缝：屋面板在使用过程中，由于受到大气温度.太阳辐射.风.雨.雪以及室内热源作用等影响，引起混凝土热胀冷缩，产生温度裂缝。 结构变形引起的裂缝：建筑物在长期使用过程中，因地基的不均匀沉降，找平层裂缝，不同建筑材料的收缩差异，吊车的频繁震动等，都能引起结构裂缝。混凝土硬化过程中的收缩，形成裂缝，混凝土施工所需水量大大超过了水泥水化所需要的用水量，

4、由于多余水分的蒸发造成砂浆收缩而引起收缩裂缝。施工裂缝：施工时混凝土振捣不密实，面层压光不好，以及早期干燥脱水，后期养护不当，都会产生施工裂缝。2.设计和施工不当引起渗漏由于屋面防水设计方案不合理，如屋面坡度过小，防水层未设分仓缝或分仓缝设计不合理等。另外，荷载计算错误，防水材料选择不当等，均可引起屋面渗漏水。屋面防水施工没有严格按照操作规程及按设计要求精心施工，局部防水措施不当，如山墙.女儿墙.檐墙.天沟.屋面板缝.烟囱或雨水管穿过防水层处，施工时未采取严密的防范措施而导致屋面渗漏水。3.防水材料质量有缺陷引起渗漏 由于一些防水材料未达到国家规定的质量标准，基层裂缝导致防水卷材的零延伸而破坏

5、；没有按照当地气温等条件选用防水材料，防水层在低温时脆裂破坏，最终导致屋面渗漏水。二、屋面防水设计与施工质量控制的措施1.尽量避免结构层混凝土产生裂缝屋面结构层尽量采用整体现浇，尤其是刚性防水屋面。采用预制钢筋混凝土板则尽量避免使用异型板，由于异型板拐角处应力比较复杂，如配筋不当，容易出现裂缝。屋面板的厚度应不小于L/(3035)（L为单项板跨度或双向板的短边跨度），一般屋面板厚度不宜小于120mm。钢筋间距不应大于150mm，且应尽量采用双层双向配筋。采用预应力混凝土是防止楼板开裂最有效的方法之一。2.加强节点及细部构造的处理严格遵照屋面工程质量验收规范对建筑防水等级规定的防水材料选用及设防

6、要求，必须由有防水设计经验的人员承担，并应根据工程特点，地区自然条件等进行防水构造设计。重视层面构造，使各层面的构造合理。如对找平层应按要求找坡后做25mm厚1:2.5水泥砂浆，保温层尽量采用憎水或吸水率低的材料等。改进节点做法，加强成品保护。由于节点构造的不合理或施工粗糙，常常是导致节点渗漏的主要原因，在节点部位应采取刚.柔结合的办法，各节点均应用密封材料填充密封，这一点尤其对刚性防水层特别重要。对于泛水处，基层需用水泥砂浆做成园角或倒角，以利于铺贴防水层。在泛水.屋脊.天沟等复杂节点部位，可采用密封材料涂布2mm厚或采用高分子卷材作为附加层。也可采用涂膜防水打底，上做卷材防水的复合防水方法

7、。防排结合，采取以防为主.以排为辅的重要原则。屋面工程的防水设计，如果坡度不够，水落口布置部位不妥和数量不足，管径偏小以及天沟.檐沟宽度不够都会造成排水不畅，极易造成屋面局部积水。长久以来，防水层处于干湿.冻融交替作用下，势必造成防水层破坏，也可由于屋面积水引发墙面连带渗漏。在大坡度基层上施工时，为防止防水层和保护层在重力作用下滑移，需采用机械固定措施，在防水层施工完毕后采用带压条或垫片的钉子固定，也可采取在保护层内加钢丝网片.钢筋弯勾锚固的方法固定。3.合理选择防水材料防水涂料具有对形状复杂.变截面以及设施较多的屋面容易施工并能形成连续.弹性.无缝.整体防水层的特点，主要代表产品有溶剂型高聚

8、物改型沥青防水涂料和聚氨酯防水涂料等。防水卷材是建筑材料中的主导产品，占防水材料总量的80%左右。它包括沥青防水卷材.高聚物改型沥青防水卷材.合成高分子防水卷材等三大系列产品。适用于防水等级一至四级的工业与民用建筑工程的屋面防水。严格按照现行技术标准及环境条件选材，确保屋面防水的耐久年限。以达到提高防水工程质量和延长防水层使用年限的目的。4.精心施工，加强防水施工管理屋面工程的防水必须由专业队伍施工，应贯彻设计意图，使用经测试合格的材料，不能任意更改。施工前必须认真编写施工方案，并贯彻执行，精心施工。遵守有关防水规范的各项规定。对防水施工全过程认真管理，做好每道工序的检查和验收工作。从设计.选

9、料.测试.施工到档案整理各个环节都应有严格的管理制度。充分了解结构层混凝土和找平层等的材料.施工情况，为防水处理做好一切准备。要注意防水屋面的维修养护，防止不应有的损坏，要时刻保持雨水口等排水流畅。由此可知，住宅工程的屋面防水设计也应遵循“多道设防，复合防水，防排结合”的原则，采取综合治理的途径。如何彻底的解决好住宅工程屋面防水的渗漏问题，不但要求我们认真贯彻执行“屋面工程技术规范”，把好防水材料质量关，最重要的是要求我们要不断提高施工水平和管理水平。Reasons of roof leakage, and quality control method is explored Pick to:

10、 the common fault of the building, the roof leakage is common, including: design, material, construction, management, maintenance and so on four aspects, to do a good job in roof waterproof, namely to have reasonable design scheme, again to choose good waterproof materials, namely according to rules

11、 of careful construction, and management of a complete maintenance measures. Key words: roof leakage reason; Quality control; Selection of materials; The construction method In recent years, China's construction industry development is very fast, but the construction quality common fault of roof

12、 leakage is good for many years has not been able to solve problems. Many new engineering occurs leakage, leakage of completion that occurs housing accounts for a large proportion. Old buildings are using organic waterproof, now also have to use fixed number of year, so the leakage phenomenon is mor

13、e serious, however, mending leakage often is much difficult than new building waterproof, tend to be here for good, there is leakage, fill again and again, users can't live in peace, formed "leakage repair year after year, year after year" the vicious circle. Every year in our country

14、is only used for roofing waterproofing maintenance up to billions of yuan. In the early ninety s, China's ministry of construction has for nearly 100 large and medium cities nationwide housing construction leakage is a random sampling investigation, sampling a total of 2072 homes, building area

15、of 7.977 million square meters, and found that there are 725 of roof leakage, and 35% of the total number of sampling. Investigations found that leakage in engineering, by adopting coating waterproof leakage rate is highest, accounting for 44.3% of the total coating waterproof engineering, followed

16、by rigid waterproof and waterproof coiled material, the leakage rate were 38.7% and 31.4% respectively. Cause the main cause of roof leakage accounted for 20% 22% in material aspects, design accounts for 18% 26%, construction accounted for 45% 48%, and the management maintenance accounts for 6% 15%.

17、 It seems that many factors cause of roof leakage, which is larger in proportion of waterproof construction and material selection. This requests us not only to standard construction according to the requirement in construction process, and to vigorously promote the active adoption of waterproof new

18、 technology, new materials and new technology. In this, reasons of roof leakage, and then talk about the design and construction quality control points. First, cause leakage of the roof 1. The structure layer caused leakage of concrete cracks (1) deformation cracks caused by temperature difference:

19、roof panel in use process, due to air temperature. Solar radiation, wind, rain, snow and indoor heat source function of impact, caused by concrete heat bilges cold shrink, produce temperature crack. 2 structure cracks caused by the deformation of buildings in the process of long-term use, due to the

20、 uneven settlement of foundation, the leveling layer cracks, shrinkage difference of different building materials, crane frequent vibration, etc., can cause structural cracks. (3) hardening of concrete shrinkage, in the process of formation of cracks, concrete construction water needed to significan

21、tly more than the cement hydration water, mortar shrinkage due to excess moisture evaporation and cause shrinkage crack. (4) construction cracks: don't concrete vibrating close-grained, when the surface pressure light is not good, and the early drying dehydration, improper maintenance, late will

22、 produce construction cracks. 2. Improper design and construction of leakage (1) due to the unreasonable roofing waterproof design, such as roof pitch is too small, waterproof layer seam not set points storehouse or warehouse design is not reasonable, etc. In addition, the load calculation errors, i

23、mproper selection waterproof materials, etc., all can cause the roof leakage. 2 roof waterproof construction is not in strict accordance with the operating procedures and careful construction according to design requirements, local waterproof measures, the mountain wall. Parapet. Eaves wall. Roof gu

24、tter. Roof plate seam. Chimney or storm sewer across the membrane, construction has not caused to take strict measures to prevent roof leakage. 3. Waterproof material quality defects cause leakage Due to some waterproof material did not meet the quality standards set by the state, the primary cracks

25、 in waterproofing materials zero extension and destruction; Not according to the local condition such as temperature choose waterproof material, waterproof layer at low temperature brittle destruction, eventually lead to roof leakage. Second, the design and construction of roofing waterproof measure

26、s of quality control 1. Try to avoid cracks of concrete structure layer (1) layer of roofing structure adopts the integral cast-in-place as far as possible, especially the rigid waterproof roof. Diction using precast reinforced concrete slab is as far as possible avoid the use of different plate, du

27、e to the different plate corner stress is more complex, such as reinforcement, prone to cracks. (3) the thickness of the roof panel should not be less than L/(30 35) (L for single span or side of bidirectional board short span), general roof plate thickness should not less than 120 mm. (4) reinforce

28、ment spacing should be not greater than 150 mm, and should try to adopt double two-way reinforcement. 5 using prestressed concrete is one of the most effective way to prevent floor cracking. 2. Strengthen the nodes and the detail structure of the processing (1) strictly conform to the roofing projec

29、t quality acceptance specification of building waterproofing of waterproof material selection and security requirements, must be borne by the waterproof design experience of the staff, and should be based on project characteristics, regional natural conditions such as waterproof structure design. At

30、taches great importance to the level of structure, all aspects of the structure is reasonable. As the leveling layer should be according to the request to find slope after to do 25 mm thick. 5 cement mortar, insulation layer as far as possible use hydrophobic or material bibulous rate is low, etc. (

31、3) improve the node practice, strengthening the protection of finished products. Because node structure is not reasonable or construction rough, often is a major cause of lead to leakage of node, the node position should be taken. Just soft combination method, application of sealing material filling

32、 sealing all nodes, and this is especially for rigid waterproof layer is particularly important. For flood water place, at the grassroots level need cement mortar to make garden Angle or Angle, so the shop is stuck the waterproof layer. In a pan of water. Roof. The roof gutter complex node location,

33、 seal material coating can be used 2 mm thick or use high polymer coil as an additional layer. Also can use waterproof coating, composite waterproof coiled material waterproof on method. (4) the combination, to give priority to. In case the important principle that the row as the auxiliary pole. Roo

34、fing construction waterproof design, if the slope is not enough, impinges mouth parts wrong layout and shortage, small diameter and a roof gutter. Eaves gutter width is not enough to cause poor drainage, local water easily to roofing. For a long time, the waterproof layer is wet. Under the action of

35、 freezing and thawing alternation, is bound to membrane damage, can also be caused by roof water wall joint leakage. 5 on the large slope base construction, to prevent the waterproof layer and protection layer in gravity fall, should adopt mechanical static measures, adopted in construction after th

36、e completion of the waterproof layer with layering or gasket nail, also can be taken within the protective layer with steel wire mesh. Steel bar curved hook fixed anchorage method. 3. Rational selection waterproof material (1) waterproof coating has a complicated shape. Variable cross-section and fa

37、cilities construction and can be more roof readily form a continuous. Elastic. Seamless. The overall characteristics of the waterproof layer, the main representative products are solvent-based polymer modification of asphalt waterproof coating, polyurethane waterproof coating, etc. Waterproofing mat

38、erials 2 is the leading products in building materials, or about 80% of the total waterproof material. It consists of asphalt waterproof coiled material. Polymer modification of asphalt waterproof coiled material. Three series of products such as synthetic polymer waterproof coiled material. Suitabl

39、e for waterproof level 1 to level 4 of industrial and civil construction roofing waterproof. (3) materials, in strict accordance with the current technical standard and environmental conditions to ensure durable life of roofing waterproof. To improve the quality of waterproof engineering and prolong the use fixed number of year for the purpose of the waterproof layer. 4. Careful construction, strengthen the management of waterproof construction The improvement of the waterproof of the roof engineering construction, must by the profe