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The Reason And Repairs Of Roof Waterproofing Membrane And Waterproof Coating Leakage

Published:2020-05-08Views:

First, the roof waterproofing membrane leaks
The roof serves as the outer maintenance structure covered by the uppermost layer of the building. Its main function is to protect human production and life from the danger of nature. In the past, asphalt linoleum has been used as the main waterproof material for roof waterproofing. However, natural wind, rain, snow, solar radiation, temperature changes and other external unfavorable factors will affect the normal use of ordinary waterproof coils, especially the impact of sunshine, temperature and rainfall, and of course some internal factors. If the roof itself is constructed, the construction method is improper, and the later use, etc., the leakage or damage of the ordinary waterproofing membrane of the roof is caused.
 
Influence of external environmental factors
1. The impact of sunshine  
The sun is detrimental to flexible waterproof materials. The energy of the sun light raises the temperature of the asphalt linoleum and induces a chemical reaction, thereby accelerating the oxidative aging of the waterproof material, reducing the toughness of the asphalt linoleum and increasing the brittleness, which is more complicated for a waterproof material system capable of photochemical reaction. In the early days of the application of ordinary waterproofing membranes, sunlight provides the energy necessary for chemical crosslinking reactions, and the strength and elasticity of the materials may be improved; but as time elapses, the light energy eventually leads to and accelerates the aging of the waterproofing membranes and break.
 

2. The impact of temperature  
High temperatures accelerate the oxidation and aging process of bituminous materials. For some plasticizers that have added plasticizers (plasticizers are generally low-molecular oils that have a high boiling point, are not easily volatilized, and have good compatibility with asphalt linoleum, can increase the toughness of asphalt linoleum), and the temperature is too high. Promotes migration of plasticizers, resulting in increased brittleness of materials. Thus, if the ambient temperature changes greatly or the temperature is low, the probability of material fracture or cracking will increase significantly. In addition, the viscous flow of the material is high at high temperatures, and plastic creep is likely to occur when the material is subjected to stress caused by an external force. The low temperature can increase the brittleness of the ordinary waterproof coil material. In a certain period of time, if the material is in a certain low temperature state, if the flexibility of the waterproof material is insufficient, the low temperature cracking and deformation fracture of the material may occur due to the accumulation of internal stress of the material. .
 
3. Impact of rainfall (including rainfall and snowfall)  
In general, the amount of rainfall has little direct impact on the performance of waterproof materials. For ordinary waterproof membranes with water resistance problems, more frequent and long-term house area water will also cause local damage. The snowfall process is accompanied by cooling and a relatively long melting process, which also increases the brittleness of ordinary waterproof materials.
 
Improper construction method
Improper construction methods are also one of the causes of leakage or damage to the roofing linoleum waterproofing membrane. For example, the roof base layer is uneven or the base layer is not cleaned, so that dust such as miscellaneous soil is mixed into the isolation layer; the leveling layer has low strength and poor quality; the roof area is relatively large, and the position of the warehouse is unreasonable. 
It is precisely because of these external environmental factors and improper construction methods that the ordinary waterproofing membrane has not leaked or damaged until its service life. They are usually “bulk-packed”, cracked and coiled with waterproof membranes. Peeling of the waterproof material and the bonding layer.  
 
The influence of the structure of the roof itself
The roof structure itself has a great influence on ordinary waterproof materials, such as the slope of the roof. If the slope of the roof is relatively large, the roof precipitation can smoothly discharge the roof, reducing the contact time between the rainwater and the asphalt linoleum waterproofing membrane. It also reduces the chance of leakage of the waterproof membrane, thereby extending the service life of the waterproof material. Impact of roof use  
In normal use, the asphalt linoleum waterproofing membrane is damaged due to the maintenance of the roof or the installation of other equipment on the roof. When the roof is overhauled, the asphalt linoleum can easily be trampled out without paying attention to protection. When other equipment is installed on the roof, it may damage the ordinary waterproof membrane for fixing.
 
Common phenomena and solutions
1. Peeling of the asphalt linoleum coil waterproof material and the bonding layer.  
The asphalt linoleum waterproofing membrane and the base layer are peeled off, which will seriously affect the waterproof quality, causing the coil to sag, the head to fall off, the rainwater to invade, and leakage.  
Most of the asphalt linoleum waterproofing membranes are caused by the quality of the leveling layer and the base layer (such as the quality of the leveling layer is not good, not fully dry, easy to sand; the unevenness of the surface of the base layer is uneven); or ordinary waterproofing membrane The quality of the material itself is unqualified; or because the construction temperature of the hot glue material and the self-adhesive coil material is low, the waterproof layer and the base layer are not firmly bonded and peeled off.  
The usual treatment methods are as follows: 1 In a small roof area, the waterproof layer can generally be cut, and then dried. After drying, apply the adhesive and re-stick, and finally paste 300mm at the slit. Wide coil strip. 2 On a large slope roof, it can be treated by mechanical fixing. It is usually nailed with nails or beading at the peeling point of the ordinary waterproofing membrane, and then sealed with a sealing material on the nail (if the steel bead is used, the steel bead must be rust-proofed). 3 In the joint between the roof and the wall, or the structure of the protruding roof, the lap joint is usually adopted. After the waterproof layer is cut, the façade waterproofing material is turned up, the leveling layer is cleaned, and the layer is covered with a full-stick method. The waterproofing membrane is bonded to the horizontal waterproofing membrane, and then the vertical waterproofing membrane is turned over and re-applied, and the overlapping width of the coil should be greater than 150 mm. 

2. "Drum kit" for waterproofing membranes.  
The occurrence of bulging of asphalt linoleum waterproofing membranes often occurs in actual engineering. Generally, it is easy to appear in the following two cases: one is that the indoor vapor permeates through the structural layer to the bottom surface of the ordinary waterproofing membrane; the other is that a certain amount of water vapor is left in the insulating layer or the leveling layer, and the water vapor evaporates. Or swell to make a bulge on a common waterproof roll. Drum kits generally develop from small to large from the bottom of the coil, and some drums are bundled into pieces. The large diameter can reach 200-300mm, and the local uplift can be as high as 50-80mm.  
For the asphalt linoleum waterproofing membrane to appear "drum bag" and leakage, generally according to the size and severity of the "drum bag", different treatment methods are adopted. When the diameter of the "bullet" is small (generally the diameter of the bulge is less than 80 mm), it is usually treated with a suction-filling adhesive. Specific practice: drill two small holes on both sides of the bulge, one hole uses a syringe to draw the air inside the bulge, the other hole is injected into the adhesive with a syringe, and then is pressed hard to make it with the base of the ordinary waterproof membrane. Strong bonding. Finally, the sealing material is tightly sealed at the two pinholes. When the diameter of the "drum bag" is large, the "drum kit" is generally cut off and re-patched.
 
3. Cracking of the waterproof layer of the coil.  
The main reasons for the cracking of the coil are: low strength of the leveling layer, poor quality; large area of ​​the roof, unreasonable setting of the joint; the cracking of the mortar leveling causes the cracking; and the abnormal temperature of the environment causes the concrete to crack or Mortar cracking and so on. For the repair of the cracking of the waterproof coil, the repair method is also selected according to the degree of damage in the actual project. For example, when the roof waterproof layer is damaged and the area is small, the sealing material can be used to fill the seam. Generally, the screed layer of 50 mm wide on both sides of the crack of the waterproof layer of the coil is cut off, the depth direction is greater than 30 mm, and then the polyvinyl chloride is irrigated. The cement is 3mm above the roof. In the case of serious damage to the roof waterproofing membrane, it is generally necessary to re-install the waterproof layer. Before the waterproof layer is re-installed, it is usually required that the construction side install an additional reinforcement layer in the construction. The "Technical Specifications for Roofing Engineering" also refers to the waterproofing of the roofing surface. Additional reinforcement layer must be set (in the waterproof process, some locations are subject to stress concentration, frequent deformation, severe rain erosion or external damage, and local damage will occur earlier, resulting in the entire waterproof layer not being repaired for a long period of time. In this case, a reinforcing layer is provided on a weak portion that is liable to cause local damage to improve the overall arming ability of the waterproof layer and prolong the service life of the entire waterproof layer). The specific method of the roofing membrane waterproof reinforcement layer is: generally adopting a polymer coil of 200-300 mm width and 1.2 mm thickness or a modified asphalt coil of 3 mm thickness to be adhered to the end of the roof panel panel, or by pressing A sensitive adhesive, and finally a large area waterproof layer.  

Second, the roof coating waterproof layer leakage
roof coating waterproof layer leakage
 
Common phenomena and repair methods
 

1. film cracking

(1) There is no flexible sealing treatment at the end seam of the roof panel, and when the roof panel is deformed, the coating film is cracked;

(2) The thick waterproof coating is applied once, and the coating shrinks and the water evaporates easily after cracking;

(3) The quality of the waterproof coating is not good, and cracking occurs after the water evaporates.

 

Repair method: first remove the coating film waterproof layer from the crack and its vicinity (expanded to 100-150 mm), leave the shovel around the shovel, and clean the base layer, then apply the same waterproof coating with the quality qualified. After the coating is dried, the coating can be applied after the coating to the desired film thickness.

 

2. film bubbling

Mainly the quality of waterproof coatings is not good enough to meet technical performance indicators.


Repair method: first remove the water-repellent layer of the coating film and its vicinity, leave the shovel around the shovel, and clean the base layer, and then apply it with the same waterproof coating of good quality.

 

3. detailed node leakage

The main causes of leakage of rainwater such as gutters, cornices, gullies and floods are as follows:

(1) The gutter, the cornice, and the floodplain are not covered with additional layers of carcass reinforcement or are not sealed;

(2) Unorganized drainage mouthwash, the sealing material is cracked or peeled off at the coating film closing mouth, causing the film to open;

(3) The water-filled carcass reinforcement material at the water drop is not enough for the length of the cup, and it is not sealed before the additional layer is added.


Repair method:

(1) If the carcass reinforcement material is not added, the original coating film waterproof layer should be removed. After cleaning the base layer, add the auxiliary carcass reinforcement material, and then apply it with new waterproof coating;

(2) If the sealing material is cracked or peeled off, it should be removed and filled with new sealing material;

(3) The film crack at the node is repaired as described above.

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