Construction Method for Non-Curing Waterproof Coating and Membrane Composite System

Compared with traditional membrane waterproofing, the composite application of non-curing waterproof coating and membrane holds significant advantages in terms of construction method, environmental requirements, and time efficiency. It can greatly reduce construction time, lower the environmental impact of construction, and minimize water leakage caused by construction defects. Therefore, it is widely used in modern building waterproofing, primarily for roof and basement waterproofing.

So, how is the composite construction of non-curing waterproof coating and membrane carried out?

I. Construction Preparation

(1) Base Surface

The vertical wall base surface shall be solid, flat, clean, and dry. The concrete surface shall be free of honeycombs, holes, protruding steel bars, and formwork seams. If the surface does not meet the requirements, additional leveling treatment shall be performed.

External wall through-pipes shall be firmly fixed. Internal and external corners of the base surface shall be chamfered to 50×50mm.

(2) On-Site Storage Requirements

Materials shall be handled with care. In accordance with specifications, materials shall be stored in a suitable location on-site, protected from direct sunlight and excessively low temperatures to prevent non-artificial damage. Materials shall not be stacked in multiple layers to avoid deformation under pressure.

II. Construction Process

Base Acceptance → Base Treatment → Application of Base Primer → Hot-Melting of Non-Curing Rubber Asphalt Waterproof Coating → Application of Non-Curing Rubber Asphalt Waterproof Coating → Laying of Self-Adhesive Waterproof Membrane → Mechanical Fixing of Membrane → Treatment of Details and Joints → Sealing and Fixing of Terminations → Self-Inspection and Repair of Waterproof Layer → Acceptance.

(1) Base Treatment

The base surface shall be solid, flat, dry, clean, free of dust and oil. Corners shall be chamfered to 50mm×50mm or rounded with a radius of 50mm.

(2) Application of Base Primer

Apply the base primer evenly on the qualified base surface. Stir the primer thoroughly before application. The application shall be uniform in thickness, without missing any areas or causing build-up. Follow the principle of 'high areas first, low areas later; vertical surfaces first, horizontal surfaces later'. The self-adhesive membrane can be laid once the applied base primer is dry.

(3) Hot-Melting of Non-Curing Rubber Asphalt Waterproof Coating

Before construction, place the non-curing rubber asphalt waterproof coating in a heating tank and heat it to a liquid state. Construction can only commence when the specified application temperature is reached: the heating temperature for manual troweling shall be ≥120°C, and for spraying ≥150°C.

(4) Application of Non-Curing Rubber Asphalt Waterproof Coating

Apply the heated non-curing rubber asphalt waterproof coating evenly onto the base surface using methods such as troweling or spraying, with a thickness of 1mm. Roll and lay the self-adhesive waterproof membrane within 3 minutes after troweling the coating. Then, gently scrape the membrane surface to expel trapped air, ensuring a firm bond between the membrane and the non-curing rubber asphalt waterproof coating.

(5) Rolling and Laying of Self-Adhesive Waterproof Membrane

Immediately after applying the non-curing rubber asphalt waterproof coating on the base surface, roll and lay the self-adhesive waterproof membrane. During laying, gently scrape the membrane surface to expel trapped air, ensuring a firm bond between the membrane and the liquid rubber.

The overlapping width of the self-adhesive waterproof membrane is 80mm, and the narrowest part shall not be less than 70mm. The overlapping edges shall be tightly rolled with a pressure roller.

After the membrane is laid, it shall be immediately fixed with steel nails or expansion screws. The fixing points shall be 10mm from the membrane edge, spaced at 500mm intervals, and covered by the membrane.

(6) Treatment of Details and Joints

6.1 Through-Pipes

The roots of through-pipes shall be plastered and coated with non-curing rubber asphalt waterproof coating, then wrapped and tightly sealed with self-adhesive waterproof membrane. The wrapping length for each through-pipe shall be no less than 250mm.

6.2 Treatment of Reserved Flanges

Reserved flanges are critical areas for external basement wall waterproofing and are also the most prone to leakage. Improper treatment will result in severe leakage risks.

6.3 Sealing and Termination of Waterproof Membrane

The membrane terminations shall be fixed with metal battens and steel nails, then sealed with sealant. The membrane termination shall be 500mm above the outdoor finished floor level.

III. Precautions

An oil-based base primer must be applied, and the non-curing rubber asphalt waterproof coating can only be troweled after the base primer is completely dry.
Construction work can only be carried out when the non-curing rubber asphalt waterproof coating is melted into a liquid state and reaches the specified application temperature.
Roll and lay the self-adhesive waterproof membrane while troweling the non-curing rubber asphalt waterproof coating, paying attention to the bonding effect of the membrane overlapping edges.
The membrane shall be mechanically fixed to prevent it from falling off during construction, and the fixing nails shall be covered by the membrane.
The self-adhesive layers of the self-adhesive waterproof membrane at the reserved flanges shall be bonded tightly after heating with the hot-melting method.

IV. Quality Acceptance Standards

All membrane overlapping edges shall be inspected and must be firmly bonded.
The bonding rate between the membrane and the non-curing rubber asphalt waterproof coating shall be ≥90%.
After the completion of waterproof construction, no cracking shall occur between the membrane or non-curing rubber asphalt waterproof coating and the base surface.
The overlapping width of the self-adhesive waterproof membrane is 80mm.

V. Finished Product Protection and Safety Precautions

Specific measures shall be implemented for the protection of finished waterproof works. Workers shall not arbitrarily damage the finished products of each process during construction. After the project completion and acceptance, a dedicated person shall be responsible for maintenance and management. It is strictly prohibited to drill holes or damage the waterproof layer after acceptance.
Areas where the laid membrane is directly exposed to sunlight for more than three weeks shall be covered and protected with plastic sheeting or other materials.
During backfilling by the civil engineering team, two waterproof workers shall be on-site for full-time supervision. Any damage to the waterproof layer shall be repaired immediately.
Backfilling soil shall be layered and compacted. One-time dumping is strictly prohibited. Backfilling soil shall not contain construction waste, stones, concrete blocks, etc. If such materials are found, construction workers shall immediately stop the work and negotiate with the civil engineering team and supervisor.

Composite Construction Method of Non-Curing Waterproof Coatings and Membranes