1. Leakage of roofing waterproofing membrane
The roof, as the outer maintenance structure of the upper layer of the building, its main function is to protect human production and life from natural danger. In the past, asphalt linoleum has been used as the main waterproof material for roof waterproofing. However, the natural wind, frost, rain, snow, radiation from the sun, changes in temperature, and other unfavorable factors will affect the normal use of ordinary waterproofing membranes, especially sunlight, temperature and rainfall. Of course, there are some internal factors. For example, the roof's own structure, improper construction methods, and later use have caused leakage or damage to the roof's ordinary waterproofing membrane.
Influence of external environmental factors
1.The influence of sunshine
The sun is not good for flexible waterproof materials. The energy of the sun's rays increases the temperature of the asphalt linoleum and induces a chemical reaction, thereby accelerating the oxidative aging of the waterproof material, reducing the toughness and brittleness of the asphalt linoleum, and the situation is more complicated for a waterproof material system that can undergo a photochemical reaction. At the beginning of the application of ordinary waterproof membranes, sunlight provides the energy necessary for chemical cross-linking reactions, and the strength and elasticity of the materials may be improved; but as time goes by, the light energy will cause and accelerate the aging and acceleration of waterproof membranes. fracture.
Influence of temperature
High temperature can accelerate the oxidation and aging process of asphalt materials. For some waterproof materials with plasticizers (plasticizers are generally low-molecular-weight oils with a high boiling point, not volatile, and good compatibility with asphalt linoleum, which can increase the toughness of asphalt linoleum), the temperature can be too high. Promote migration of plasticizers, resulting in increased brittleness of the material. In this way, if the ambient temperature changes greatly or the temperature is low, the probability of material fracture or cracking will increase significantly. In addition, under high temperature conditions, the material is highly viscous, and when the material is subjected to stress caused by external forces, plastic creep is liable to occur. Low temperature can increase the brittleness of ordinary waterproof membrane materials. In a certain period of time, if the material is not flexible enough in a certain low temperature state, as the internal stress of the material slowly accumulates, it may cause low temperature cracking and deformation of the material. .
3. Impact of rainfall (including rainfall and snowfall)
Generally speaking, the amount of rainfall does not directly affect the performance of waterproof materials. For ordinary waterproofing membranes with water resistance problems, more frequent and long-term water in the roof area will also cause local damage to this. The snowfall process is accompanied by a cooling down and a longer melting process, which also increases the brittleness of ordinary waterproof materials.
4. Improper construction methods
Improper construction method is also one of the reasons that cause the roof asphalt linoleum waterproofing membrane to leak or damage. For example, the roof base is uneven, or the base is not cleaned, so that dirt and other dust are mixed to form the isolation layer; the leveling layer has low strength and poor quality; the roof area is relatively large, and the sub-slots are not set properly.
It is precisely because of these external environmental factors and improper construction methods that ordinary waterproof membranes have leaked or damaged before they reach the end of their useful life. They are usually “bulged”, cracked, and coiled with waterproof membranes. Peeling of waterproof material and bonding layer.
5. The influence of the roof structure
The structure of the building roof itself has a greater impact on ordinary waterproof materials, such as the slope of the roof. If the roof slope is relatively large, the roof precipitation can be smoothly discharged from the roof, reducing the contact time between rainwater and asphalt linoleum waterproofing membrane. It also reduces the probability of leakage of the waterproof membrane, thereby extending the service life of the waterproof material. Impact of roof use process
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 be easily damaged without attention. When other equipment is installed on the roof, the ordinary waterproof membrane may be damaged in order to fix it.
Common phenomena and solutions
1. Stripping of waterproofing material and bonding layer of asphalt linoleum coil.
The peeling of the asphalt linoleum waterproofing membrane from the base layer will seriously affect the waterproof quality, causing the membrane to sag, the end to fall off, rain invasion, and leakage.
Most of this situation of asphalt linoleum waterproofing membrane is because the leveling layer and the quality of the base layer are not controlled (such as the quality of the leveling layer is not good enough, it is not sufficiently dry and easy to get sand; the surface of the base layer is uneven); The quality itself is unqualified; or due to the low construction temperature of the hot glue and self-adhesive coil, the waterproof layer and the base layer are not firmly bonded and peeled off.
The usual processing methods are as follows
① In a small range of roofing, it is generally possible to cut the waterproof layer and then dry it. After it is dry, apply adhesive again to paste it, and then paste a 300mm wide strip of strip at the slit.
② On large-slope roofs, mechanical fixing methods can be used for processing. Usually nailed with strips or strips at the peeling place of ordinary waterproof coiled material, and then sealed with sealing material on the nails (if steel strips are used, the steel strips must be rust-proofed).
③ The joints between the roof and the wall, or the structure protruding from the roof are usually overlapped. Usually, after the waterproof layer is cut, the facade waterproof membrane is turned up, the leveling layer is cleaned, and a layer is applied with full adhesion. The waterproof membrane is bonded with the horizontal waterproof membrane, and then the facade waterproof membrane is turned down and pasted again. The overlap width of the membrane should be greater than 150mm.
2. The "bulb" of waterproof membrane.
The bulging of the asphalt linoleum waterproofing membrane often occurs in actual engineering. Generally, it is relatively easy to occur in the following two cases: one is that the indoor vapor penetrates 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 insulation layer or the screed layer, and the water vapor evaporates Or the swelling of ordinary waterproof membranes. Drum kits generally develop from small to large starting from the bottom coil. Some sizes of drum kits are connected in series, with large diameters up to 200-300mm and local bulges up to 50-80mm.
When the asphalt linoleum waterproofing membrane is “bulged” and leaks, different treatment methods can generally be adopted according to the size and severity of the “bulged”. When the diameter of the "drum bag" is small (generally refers to the diameter of the drum bag is less than 80mm), it is usually treated by suction irrigation. Specific method: Drill two small holes on both sides of the bulge. One hole uses a syringe to draw out the air in the bulge, and the other hole uses a syringe to inject the adhesive, and then presses it firmly to make it the base layer of the ordinary waterproof membrane. Strong adhesion. It was then sealed tightly with sealing material at the two pinholes. When the diameter of the "bulb" is large, the "bulb" is generally cut off and repaired again.
3. Cracking of the coil waterproof layer.
The main reasons for the cracking of the coil are: low strength of the leveling layer and poor quality; large area of the roof, unreasonable setting of sub-slots; cracking of the mortar leveling layer caused by dryness and wetness; and irregular changes in ambient temperature leading to cracking or mixing of the soil Cracking of mortar and so on. For the repair of cracks in waterproof membranes, the repair method is also selected according to the degree of damage in actual engineering. For example, when the damage degree of the waterproof layer of the roof is small and the area is small, the jointing method of the sealing material can be adopted. The usual method is to first cut off the 50mm wide screed on each side of the crack of the waterproof layer of the coil, the depth direction is greater than 30mm, and then heat the polyvinyl chloride. It is also 3mm above the roof. In the case of serious damage to the roof waterproofing membrane, it is generally necessary to reset the waterproof layer. Before resetting the waterproof layer, the construction party is usually required to add an additional reinforcement layer during the construction. The "Technical Specifications of Roof Engineering" also mentions that when the roof is waterproof Additional reinforcement layers must be provided (during the waterproofing process, due to stress concentration, frequent deformation in some locations, severe rain erosion or external force damage, local damage will occur earlier, resulting in the entire waterproofing layer needing to be repaired before it reaches the end of its durability. In this case, a reinforcing layer is provided on the weak part that is liable to cause local damage to improve the overall defense ability of the waterproof layer and extend the service life of the entire waterproof layer). The specific method of roofing membrane water-repellent reinforced layer is: generally use 200-300mm wide, 1.2mm thick polymer coil or 3mm thick modified asphalt coil single-sided point at the end of the roof panel, or use pressure Sensitive adhesive, and later covered with a large area waterproof layer.
Leakage of waterproofing layer of roofing coating
Common phenomena and repair methods
1. Cracking of the coating film
(1) There is no flexible sealing treatment at the end seam of the roof panel. When the roof panel is deformed, the coating film is cracked;
(2) One-time thick waterproof coating is applied, and the coating film is easy to crack after shrinking and water evaporation;
(3) The quality of the waterproof coating is not good, and cracks occur after the water evaporates.
Repair method: First remove the cracked coating and the waterproof layer of the coating (extended to 100-150mm), leave a diagonal sipe around the shovel mouth, and clean the base layer, and then use the same waterproof paint of qualified quality to be painted in sections. After the coating is dried to form a film, the subsequent coating can be applied to make it reach the required coating film thickness.
2. Coating bubble
The main reason is that the quality of the waterproof coating is not good enough to meet the technical performance indicators.
Repair method: First, remove the coating film waterproof layer near and around the bubbling area, and leave a sloping edge around the shovel mouth, and clean the base layer, and then apply the same waterproof coating with good quality.
3.Detailed node leakage
The main causes of rainwater leakage in gutters, cornices, gutters, flooding, etc. are as follows:
(1) No additional layers of carcass reinforcing material or no sealing treatment have been added to the gutters, cornices and flooding places;
(2) Non-organized drainage eaves, where the sealing material cracks or peels off at the coating film opening, causing the coating film to open;
(3) The water-reinforced carcass reinforcement material at the water drop mouth, or the length of the carcass reinforcement that extends into the mouth of the cup is not enough, and it is not sealed before the additional layer is laid.
(1) If the carcass reinforcement is not added, the original coating waterproof layer shall be removed, and after the base layer is cleaned, auxiliary carcass reinforcement is added, and then coated with new waterproof paint.
(2) If the sealing material is cracked or peeled off, it should be removed and filled with new sealing material;
(3) Cracking of the coating film at the joints is repaired as described above.