Wet‑laid Pe Pp Waterproof Membrane With Cement Mortar, No Hot Melting Required

Construction Process of Polyethylene‑Polypropylene Composite Membrane for Bathroom

Wet‑lay method with cement bonding mortar, for bathroom & kitchen. Use special cement adhesive.

1. Substrate Treatment

Make bathroom substrate solid and flat. Remove dust, oil stains and loose sanding layers. Repair grooves, holes and cracks with cement‑sand mortar. Make R20‑R30 mm rounded corners at internal corners, pipe roots and floor drains without sharp edges. Substrate can be damp, but no standing water.

2. Additional Layers for Details

Install same‑material additional layers at corners, floor drains, pipe roots and sleeves, width ≥300 mm. Bond tightly with cement adhesive, squeeze out air, no hollowing or curling.

3. Prepare Cement Bonding Mortar

Mix special cement adhesive according to ratio until free of dry powder and lumps. Mix for immediate use and finish within pot life.

4. Large‑area Membrane Laying

Snap reference lines on walls. Construct wall first, then floor. Spread cement adhesive evenly on substrate, also apply thin layer on membrane back side. Lay polyethylene‑polypropylene composite membrane. Scrape repeatedly from inside outward to expel air. Ensure tight contact, avoid hollowing and wrinkles. Overlap width ≥100 mm. Fill full cement adhesive within lap joints. Membrane height for shower zone ≥1.8 m, other wall areas ≥300 mm.

5. Termination & Detail Sealing

Cut membrane neatly around pipes and floor drains. Seal joints fully with cement adhesive. Tuck and seal membrane termination on wall into groove.

6. Curing

Allow natural curing for 24‑48 h. No treading or water splashing before full curing.

7. Water‑Closing Test

Carry out water‑closing test after curing. Water depth 20‑30 mm, keep for 24‑48 h. Qualified if no leakage downstairs.

8. Protective Layer & Tile Installation

Apply cement‑sand protective layer after passing water test, then lay ceramic tiles.

Key Construction Notes

1. Suitable temperature: 5℃‑35℃. Curing slows down under low temperature.
2. Do not use plain cement; adopt special cement adhesive for polyethylene‑polypropylene membrane.
3. Dry‑lay is forbidden. Full bonding with cement adhesive is mandatory.