Sbs Waterproof Membrane For Engineering Use With Excellent Weather Resistance

Composite Construction of Non‑curing Rubber‑Bitumen Waterproof Coating + SBS Modified Bitumen Waterproof Membrane

Process Principle: The non‑curing coating serves as the bottom bonding and sealing layer, while the SBS membrane acts as the main waterproof layer. The non‑curing material maintains permanent viscosity, self‑heals micro‑cracks and prevents water channeling. The SBS membrane provides mechanical strength and weather resistance. The two materials form a coating‑membrane composite waterproof system, widely applied for basement roof slabs, roofs, base slabs and side walls.

1. Substrate Requirements

1. The substrate shall be solid, flat and clean. Remove laitance, oil stains and sharp protrusions; no standing water on surface. Repair and level cracks and holes in advance.
2. Internal and external corners shall be formed into circular arcs with R≥50 mm for better fitting of waterproof layers.
3. Apply matching primer (cold base oil). Proceed to the next construction step only after the primer is fully dried.

2. Additional Layers for Joint Details (pipe roots, internal/external corners, drain outlets, post‑casting strips, construction joints)

1. Scrape‑apply non‑curing rubber‑bitumen coating at detail positions with thickness ≥1.5 mm, then immediately lay SBS membrane additional layers. The width of additional layer shall be ≥500 mm, 250 mm on each side of internal and external corners.
2. Roll and compact additional layers to eliminate hollowing and wrinkles. Construct the large‑area composite waterproof layer after additional layers are finished.

3. Construction of Non‑curing Rubber‑Bitumen Waterproof Coating

1. Heating: Heat with special hot‑melting equipment. Scrape‑coating temperature: 120‑140 ℃; spraying temperature:150‑170 ℃. Temperature shall never exceed 220 ℃ to avoid material aging and carbonization.
2. Construction Methods ‑ Scrape‑coating method: Suitable for small‑area sections and details. Control thickness within 1.5‑2.0 mm, ensure uniform application without missing spots. ‑ Spraying method: Suitable for large‑area roof slabs and roofs, featuring high efficiency and uniform thickness. Total coating thickness:1.5‑2.0 mm.
3. Critical time requirement: Lay SBS membrane within 3 minutes while the non‑curing coating is hot. Cooled‑and‑skinned coating will cause inter‑layer debonding and hollowing.

4. Laying of SBS Modified Bitumen Membrane (Hot‑bond Composite Process)

1. Snap reference lines, pre‑position the membrane and align overlapping edges.
2. Lay SBS membrane directly onto the hot non‑curing coating. Roll repeatedly with pressure roller to exhaust air completely, so that the membrane bottom is fully bonded to non‑curing coating for full‑area adhesion.

Note: No need to heat‑melt the membrane bottom with spray gun. Bonding is achieved by high temperature of hot non‑curing coating. Only hot‑melt and seal the membrane overlapping joints.

3. Overlap dimensions: Long‑side overlap ≥100 mm, short‑side overlap ≥100 mm. Offset short‑side joints between upper and lower layers by ≥500 mm.
4. Heat SBS overlapping edges with spray gun until bitumen melts and overflows to form uniform sealing beads. Roll tightly to prevent water channeling at joints.
5. Vertical surfaces: After scrape‑applying non‑curing coating, hot‑melt lay SBS membrane to ensure firm bonding on vertical surfaces; seal and fix membrane termination ends.

5. Subsequent Procedures & Acceptance

1. Overall inspection: No hollowing, edge lifting, wrinkles or missing overlaps; all detail sections shall be complete and continuous.
2. Carry out water‑closing / water‑spraying test for underground projects. Roof water‑storage test for 24 hours with zero leakage.
3. Construct protective layer promptly after waterproof layer passes acceptance, to prevent damage from long‑term sunlight exposure.

6. Construction Precautions

1. Environmental condition: Construct within 5‑35 ℃. Construction is forbidden under rain, dew or wind force ≥Grade 5.
2. For hot‑work operations, place fire extinguishers on‑site and take anti‑scald protection measures.
3. Non‑curing coating is only used as bonding‑sealing layer. It cannot be used for direct exposure. It must be covered by SBS membrane or protective layer.
4. Thickness control: Average thickness of non‑curing coating shall not be less than designed value. Needle thickness gauge can be adopted for inspection.