Homogeneous Epdm Waterproofing Membrane Jl-1

Construction Technology of EPDM Rubber Waterproof Membrane for Underground Works

1. Substrate Treatment

After concrete bedding completion, make cement‑mortar leveling layer solid and flat. Remove laitance, dust, oil stains and sharp protrusions. Repair honeycombs, cracks and holes with polymer mortar. Form R≥50 mm rounded arcs at internal and external corners. Clean and finish through‑wall sleeves, post‑pouring belts, construction joints and deformation joints. Substrate shall be dry with moisture content ≤9%, no standing water. Apply matching primer for sand‑loose areas. Lower underground water level ≥300 mm below foundation base elevation.

2. Apply Base Primer

Apply matching base primer evenly without missing or thick accumulation. Emphasize coating on details. Proceed when primer is dry‑to‑touch.

3. Additional Layers for Details

Install same‑material EPDM additional layers at corners, pipe penetrations, pile heads, post‑pouring belts, construction joints and deformation joints. Width ≥500 mm. Bond tightly without hollowing or wrinkles.

4. Marking‑out & Pre‑relaxation

Snap reference lines according to membrane width plus lap width. Unroll and relax membrane for 30 min to release internal stress. Lay horizontal surface first, then vertical wall. Loose‑lay / dot‑bond for floor slab; full‑bond for exterior vertical wall with anti‑slip measures.

5. Apply Special Adhesive

Coat matching EPDM adhesive on both substrate and membrane back. Reserve 80‑100 mm lap zone without adhesive. Apply evenly. Flash‑off 30‑60 min until dry‑to‑finger but still tacky before laying.

6. Membrane Laying & Air‑rolling

Lay along reference lines. Roll from center to edges on horizontal surface. Lay vertical membrane from bottom upward. Roll thoroughly to expel air. Do not stretch membrane. Long‑side lap ≥100 mm, short‑side lap ≥150 mm. Stagger seams ≥1/3 membrane width. Joints at horizontal‑vertical transition shall stay on horizontal surface, ≥600 mm away from vertical wall.

7. Lap Joint Sealing

Clean lap surfaces with special cleaner, apply lap adhesive, bond after flash‑off and roll firmly with seam roller. Protect overlap end laps for later connection with wall membrane.

8. Termination Fixing & Sealing

Insert vertical membrane end into groove, fasten with metal termination bars and seal with sealant. Reinforce sealing around pipe penetrations.

9. Inspection, Repair & Protective Layer

Fully inspect waterproof layer, repair damages, curled edges and joint defects. Floor slab: Cast fine‑aggregate concrete protective layer promptly. Exterior wall: Install polystyrene board protection before backfilling. Avoid sharp stones hitting membrane during backfill.

10. Acceptance

Carry out water‑closing test for floor slab. Inspect exterior wall completely before backfilling.

Construction Environment

Working temperature: 5‑35℃. Stop work under rain, standing water, dew or wind ≥Grade 5. Adhesives are flammable; ensure ventilation and fire‑safety on site.