Polyurethane waterproofing is used in the maintenance of existing waterproof layers

China Paint Online News Information: Building roof waterproofing is divided into exposed waterproof and covering protective layer or decorative material type waterproof. With the deteriorating of the waterproof layer, in order to maintain the waterproof function of the building, the waterproof layer must be repaired.this paper introduces the maintenance of the existing waterproof layer, not with polyurethane waterproof material for a comprehensive renovation of the building, but to make full use of the building's existing waterproof layer, supplemented by polyurethane waterproof material for maintenance.1, the waterproof layer of general residential buildings the existing waterproof layer of large residential buildings, mostly asphalt waterproof or exposed asphalt waterproof mainly.
asphalt waterproof maintenance can take the method of completely removing the existing waterproof layer and reset the waterproof layer. However, in order to avoid the risk and cost of leakage in the construction, more of the existing exposed waterproof foaming and cracks to be partially repaired, the rest of the use of "covering method" waterproof treatment. In this case, materials of the same material as the existing waterproof layer, or insulated coils that inhibit the migration of plasticizers, should be used in other materials. Although the waterproof materials used in the existing waterproof layer alteration are different, but in recent years, the use of asphalt-containing waterproof coils still accounted for the majority, mainly because asphalt waterproof coils in the factory production, quality is guaranteed.2, the advantages of polyurethane waterproof the use of asphalt waterproof and single-layer sheet waterproof, the material inevitably to break, cut, overlap, molding and other operations, so, must use stereotyped materials.
, almost all of these methods are mechanically fixed with metal parts, or bonded first with fixtures. This construction method is difficult because the base may be irregular and the component size is limited. Slightly improper, will induce poor bonding and floating, or in the overlap of the gap, resulting in the overall performance of the waterproof layer decreased. In particular, the pipe foundation, television antenna foundation, small daughter wall cap wood, steps and other parts, the use of waterproof coils is difficult to bond firmly with its grass.on the same waterproof construction surface, it is advisable to use a single coil construction, but in asphalt coils and single-layer sheet construction difficult parts, should be used other methods. In particular, the coating waterproof coating has the characteristics of infinitive materials, can be adapted to the construction of complex shapes, and in principle at the end and so on do not use metal fixation. Polyurethane is the most widely used waterproofing method in the standard manual for public building works, the standard manual for alteration of public building works, and the standard manual for construction works.3, polyurethane coating waterproof with other waterproof materials 3.1 with PVC waterproof use
on the roof antenna base, PVC coil end of the head is difficult. PVC sheet spread to the foundation, the end is treated with sealant, but there is a gap. PVC sheet can be applied to the foundation facades, the end of which is waterproof construction of polyurethane coating film, which can reduce the risk of leakage. The end of PVC does not use metal parts for post-treatment, but first paste PVC sheet to the steel plate, in the PVC sheet and polyurethane coating waterproofing with the part with a special base coating treatment, coating polyurethane coating.Another example is that there are several pipes on the basis of the equipment pipe, under the equipment pipe can not be applied polyurethane waterproof coating, at this time under the foundation inserted 2mm thick PVC sheet, on the PVC coating polyurethane waterproof coating, forming a composite waterproof layer.3.2 in conjunction with rubber sheet
When applying polyurethane waterproof coating on rubber sheet waterproofing, attention must be paid to the effect of solvents contained in the general polyurethane coating on the coil.
the existing waterproof layer if it is rubber sheet, the residual stock of the surface coating becomes an important inspection item, the surface coating occurs a large grinding time, with special base coating treatment, can maintain the compatible with polyurethane waterproofing.
, the newly paved rubber sheet is also necessary to be treated with a special base coating when used in conjunction with polyurethane waterproof coatings.
addition, environmentally friendly polyurethane coating waterproof (low solvent or water-based), due to the impact of solvents (organic), the expansion risk of the sheet itself is small, bonding compatible trust is high.
3.3 with asphalt (modified asphalt) exposed waterproofing in conjunction with the use of
asphalt exposed waterproof surface has grainy roof coils directly coated coating technology, is under study, at present can not be widely promoted.
However, the application of polyurethane coating waterproofing is also diversifying, due to the bottom layer of cushioning coils (insulation coils) of composite work methods, both waterproof layer of lattic coated coil surface with a base coating (sealant) treatment, if the laying of buffer coils, it is possible to apply polyurethane waterproof coating methods.insulation coil material, according to manufacturers vary, the bottom surface has a bonding layer or fiber substrate, asphalt waterproof and polyurethane waterproof can be used together, but the end seal treatment still needs attention.
3.4 Polyurethane waterproofing should be paid attention to when using with other waterproof materials
Pay attention to adhesion, pay attention to waterproof layer and the grass may be stripped.
the construction of polyurethane waterproof coating on PVC waterproof coils, pay attention to the bonding between coatings and coils, plasticizer migration caused by pollution problems.4, conclusionpolyurethane waterproof coating in the existing waterproof layer maintenance applications, will encounter some technical problems, such as bonding problems, incompatible problems, research on these issues, will contribute to the application of polyurethane waterproof coating development.