TPO / FPO Single-Ply Flat Roof Membrane – Reinforced White, Heat-Welded, 20m x 1.05m Roll (21m²)

If you have priced up a warm flat roof and been told the waterproofing needs to be a welded single-ply rather than a taped or bonded sheet, this is the roll you would be buying: a white, polyester-reinforced TPO/FPO (flexible polyolefin) membrane, 20m long by 1.05m wide, that is mechanically fixed to the deck and then joined into one continuous covering with a hot-air welder.

It is a trade-installer product, not a DIY kit. The seams only perform if they are welded correctly, so please read the "Before you order" section below before you add it to your basket.

Why choose a polyolefin (TPO/FPO) single-ply?

• Plasticiser-free formulation. Unlike PVC single-ply, polyolefin membranes do not rely on plasticisers to stay flexible, which is the main reason contractors specify them.
• Welded, monolithic seams. Adjacent sheets are joined by hot-air welding, so the roof is waterproofed by a fused joint rather than by adhesive or tape.
• Polyester net reinforcement. The scrim is what allows the sheet to be fixed mechanically through the membrane edge and to resist wind uplift loads on the fixings.
• Vapour permeable. The membrane is described by the supplier as vapour permeable, which suits correctly designed roof build-ups where condensation risk has been assessed.
• White upper surface, black underside. The light finish reflects more solar heat than a dark membrane, and gives a clean, uniform look on visible roofs and parapet-edged extensions.

Where it is used

Mechanically fixed single-ply roofs over concrete, timber or metal decks: flat-roof extensions, garages, outbuildings and larger domestic, commercial and industrial roofs, on both new-build and refurbishment projects. Upstands, parapets and penetrations are formed by cutting and welding the same membrane.

Specification

Membrane thickness is not published by the manufacturer for this product, so we do not quote one. If a specifier needs it, ask us before ordering.

How much do I need?

One roll is 20m x 1.05m, a nominal 21m². Your finished roof will always use more than its plan area: sheets must overlap so the seams can be welded, and the membrane also runs up parapets, kerbs and around outlets. Work out the roof in 1.05m-wide strips, add the seam overlaps and upstand heights, then add an allowance for cutting waste. For example, a 3m x 6m roof needs three 6m strips laid across its 3m width, about 18m of the 20m roll, before any parapet upstands or waste are added, so even a small roof can run close to a full roll and larger roofs need several. Measure your actual layout rather than dividing the roof area by 21.

Before you order: what this is and is not

• Membrane only. The roll does not include insulation, vapour control layer, fixings and plates, seam cleaner, edge trims, outlets or detailing accessories.
• It needs a hot-air welder. The seams must be welded with suitable single-ply welding equipment by a trained installer, following the manufacturer's system instructions for temperatures, seam widths and fixing patterns. A heat gun and a roller used by an inexperienced fitter is not a substitute.
• The build-up must be designed. Deck type, insulation, vapour control, fixing schedule and wind-uplift requirements vary by roof and location. If you are not sure, have the roof specified before ordering.
• Check fire and regulatory requirements. We do not quote a fire classification for this roll. If your roof is close to a boundary or needs a specific external fire rating, confirm the rating of the complete system with the manufacturer or your building control officer.
• Not for DIY beginners or stick-down repairs. If you want a DIY-friendly flat roof, a one-piece EPDM rubber system is a simpler choice, such as our 1.2mm EPDM rubber roofing membrane.

Installation overview

1. Prepare a clean, sound, dry deck and lay the vapour control layer and insulation for a warm roof.
2. Roll the membrane out in 1.05m strips with the specified side laps, and fix through the lap with the system's fixings and plates.
3. Hot-air weld each overlap to form a continuous seam, and probe-check the welds.
4. Form upstands, corners and penetrations from cut pieces of the same membrane, and weld them in.

Related products

A welded single-ply is only one layer of a warm roof. These items from our range fit into the same build-up:

• Polythene vapour control layer for laying on the deck beneath the insulation.
• Foil-faced PIR insulation board for the warm-roof layer between the vapour control layer and the membrane.
• PVC single-ply roofing membrane if you prefer a PVC system. Note that PVC and polyolefin membranes are different polymers and are not welded to each other, so choose one type per roof.

Frequently asked questions

Is this the same as a PVC single-ply membrane?

No. Both are hot-air welded single-ply membranes, but this roll is a polyolefin (TPO/FPO) and is plasticiser-free, while PVC membranes contain plasticisers. The two should not be mixed on the same roof, and different types use different welding settings.

Can I install it myself?

Only if you are trained and equipped for welded single-ply work. It requires a hot-air welder, the correct fixings and a fixing pattern for your deck and wind zone. This is normally a job for a specialist flat-roofing contractor.

What deck can it go on?

The supplier states it is suitable for concrete, timber and metal decks as part of a properly designed mechanically fixed system. The deck must be sound, dry and suitably prepared, and the fixings must suit the deck type.

Are fixings and plates included?

No. Fixings, plates, insulation and vapour control layer are sold separately and should be specified for your roof's deck and loading.

How wide are the seams and what is the roll coverage?

The roll is 1.05m wide and 20m long, a nominal 21m². Seam overlap width is set by the manufacturer's system instructions, so the usable coverage is lower than 21m².