Sand-surfaced Self-adhesive Polymer Modified Bitumen Waterproof Membrane Manufacturer

Construction Method of Self‑adhesive Polymer‑modified Bitumen Waterproof Membrane

1. Substrate Treatment

1. The substrate shall be concrete or cement‑mortar leveling layer, which should be flat, solid, free of sanding, hollowing and sharp protrusions.
2. Make R50 circular arcs at internal and external corners. Remove dust, oil stains, gravel and other debris.
3. The substrate can be damp, but no standing water is allowed. Standing water shall be dried or wiped off before construction.
4. Repair cracks and holes with cement mortar in advance to achieve smooth surface.

2. Application of Primer (Optional)

For dry substrate, apply matching primer in one thin even coat. Start membrane installation after the primer is fully dry and non‑tacky. Primer can be omitted for damp substrate, direct installation is acceptable.

3. Snap Reference Lines

Snap reference lines on the substrate according to membrane width to control lap width. Long‑side lap ≥80 mm, short‑side lap ≥100 mm.

4. Membrane Installation (Cold Self‑adhesive Method)

1. Peel off the release film on the bottom side of membrane. Align with reference lines, roll forward while peeling the release film.
2. Keep proper tension during installation to avoid stretching and wrinkling.
3. Use rubber roller to roll from center to both sides to exhaust air, so that membrane closely bonds to substrate and eliminate hollowing.
4. Lap adjacent membranes along marked lines, remove release film on lap area, and roll fully with roller to ensure tight sealing of lap joints.

5. Reinforcement Treatment for Details

Apply additional reinforcement layer first for weak positions such as internal / external corners, pipe roots, post‑pouring belts and construction joints. The width of additional layer shall be ≥500 mm, then carry out large‑area membrane installation.

6. Inspection of Lap Joint Sealing

After full installation, inspect all lap edges to avoid warping and open joints. Seal warping positions with sealing compound. For sand‑surfaced membrane, clean off fine sand within lap zone to guarantee firm bonding.

7. Protective Layer Construction

This is non‑exposed membrane. After waterproof layer acceptance, construct protective layer timely. Cement‑mortar protective layer for roof; fine aggregate concrete protective layer for underground base slab, to prevent long‑term sunlight exposure and mechanical damage.

8. Construction Notes

1. No open‑flame torching is permitted, cold‑applied only.
2. Do not construct in rainy weather or dew‑covered conditions.
3. Increase rolling pressure properly under low‑temperature environment to secure bonding performance.