Application
Raft Foundation Waterproofing
Raft waterproofing places a designed horizontal membrane assembly under or around the raft according to the structural waterproofing design—often SBS bitumen—with critical continuity into retaining walls and at construction joints. Petroseal supports raft detailing with membrane selection, protection layers, and coordination with waterstops. Exact build-up must follow the project drawings.
Recommended systems
Match site condition to a Petroseal system page.
| Condition | Recommended system |
|---|---|
| Horizontal raft membrane | SBS horizontal assembly |
| Raft-to-wall transition | Double-layer or detailed SBS |
Technical requirements
- —Blinding and substrate preparation per design
- —Protection before reinforcement and concrete
- —Documented transitions to vertical walls
Limitations
- —Field improvisation at transitions is a common failure source
Application sequence
- Prepare blinding
- Install horizontal membrane and protection
- Form raft and maintain detailing at edges
- Continue vertical system without gaps
Common failure modes
- —Broken continuity at wall junction
- —Rebar puncture without repair
Related systems
- SBS Waterproofing System
SBS waterproofing systems use styrene-butadiene-styrene modified bitumen membranes for elasticity and low-temperature fl…
- Double-Layer SBS Basement System
A double-layer SBS basement system installs two plies of SBS-modified bitumen membrane to provide redundancy under hydro…
Related products
- PetroGrip SBS
SBS-modified torch membrane—3mm and 4mm with plain, aluminum, or granular surfacing.
- PVC Waterstoppers
PVC water-stops for watertight concrete construction joints.
Related projects
- Emporium Mall
Johar Town, Lahore · Commercial
Technical downloads
- PetroGrip SBS Waterproofing Membrane TDS
Polyester-reinforced SBS-modified torch-applied bitumen membrane — 3 mm nominal thickness, 60/70 bitumen base.
Technical guides
- Basement Waterproofing with Bitumen Membrane Systems
Design and install basement waterproofing with PetroGrip SBS torch membrane and PetroSelfGrip sheets—substrates, laps, protection boards, and Lahore-manufactured systems for nationwide projects.
FAQ
- Can SBS membrane be applied under a raft?
- Yes, when the waterproofing design specifies a horizontal membrane under the raft with approved protection. Follow the consultant’s detail—not a generic catalogue sketch alone.