Method · Sheet membrane
Single-ply PVC or TPO sheets with seams welded by hot air — widely used on large roofs, fast to lay and able to be mechanically fixed.
A single-ply plastic (PVC) sheet whose seams are welded with hot air into one continuous skin.
Large roofs — a widely used sheet, quick to lay and able to be mechanically fixed.
Seams are peel-tested, and fixed roofs get a fastener pull-out test.
Layers (built up from the bottom)
Reinforced sheet that stands up to the sun. Screwed down; seams heat-welded.
A fleece that separates the sheet from the deck.
Clean, dry concrete, ready to receive the system.
The figure shows one typical build-up. The actual layers are decided after we see the site.
We inspect the substrate — moisture, cracks, laitance — before choosing the system. A wrong substrate defeats any membrane.
Seams are hot-air welded and peel-tested; mechanically fixed roofs get a fastener pull-out test.
Roofs and tanks get a water (ponding) test before handover; the result is signed off jointly.
Sheets are chosen by where they go — roof, below ground or containment. If another one fits better, we will say so.
| Sheet | Strength | Where |
|---|---|---|
| APP (Torch-on) | Copes with heat & sun better than SBS — common in hot climates | Roof, deck |
| Self-Adhesive | Easy install, no torch | Foundation, basement wall |
| SBS | Cold-flexible | For cold climates |
| PVCthis page | Widely used on large roofs, easy to install | Roof |
| TPO | Chlorine- and plasticiser-free, recyclable where taken back | Roof |
| HDPE | Resists most acids, alkalis and salts — below ground / containment | Below ground, containment |
| ECB | Cold-flexible, below ground | Below ground |
| EPDM | Rubber with excellent heat, UV & weather resistance; not for oil or solvents | Roof, below ground |
| Bentonite / GCL | Clay sheet, swells with water | Below ground |
Also with this method:Thai Oil (OC3) · Stock Exchange of Thailand (SET), Bangkok · PTTTLNG (PTT LNG) · Polyols (PY) Project · Brose Fahrzeugteile, Rayong · Mae Fah Luang University · Muang Thai Insurance · Phitsanulok Airport · Thai Airways · Thai Airways U-Tapao Facility, Rayong · Office of the National Broadcasting and Telecommunications Commission (NBTC), Bangkok · Mandarin Oriental Hotel, Bangkok · Dusit Thani Pattaya · So Sofitel Hua Hin · Thai Beverage · IRPC Substation E26 (MCC) · IRPC CCR, Electrical Substation & IP Water Treatment Plant · PTT WCS Wang Noi, Ayutthaya · Landmark Waterfront · JW Marriott Khao Lak Family Resort · Liberty Square · Dusit Thani Hua Hin · Thai Sekisui Foam · Isuzu Tripetch · DTS Bangpu · Terragro Fertilizer · STC Nicca · Viscofan Parbat Factory, Rayong · Five Star Factory · Vinythai Sakura Project (HCl) · Silpakorn University · EGAT Wang Pladuk Power Control Center
The area, the state of the substrate (cracks, wet spots, or an old membrane to remove), the system and number of layers, whether it is exposed to the sun, and the hours we can work. Send photos and drawings on LINE and we will check the site and quote.
PVC is widely used on roofs and easy to install. TPO is a thermoplastic polyolefin sheet, free of chlorine and plasticisers and recyclable; its weather resistance depends on the grade. Both have hot-welded seams, and installation and testing are the same.
Seams are hot-air welded into one piece and peel-tested; on mechanically fixed roofs the fasteners get a pull-out test. The roof is water-tested before handover and signed off jointly.
Send the roof area, what is on it now and a few photos. We check the site and propose the sheet that fits.
Only want materials? psw-chemical.com ↗TEL +66 2 552 6468 · sales@passawarn.com