Liquid Roofing vs Single Ply: When to Use Each
Single ply membrane is our specialism, but it isn’t the right answer for every roof. Sometimes a liquid-applied system is the better tool for the job. Both, importantly, leave glued EPDM rubber and brittle GRP fibreglass behind. Here’s how the two compare and when we’d reach for each across Doncaster and South Yorkshire.
What is liquid roofing?
Liquid roofing is a waterproofing coating that’s painted or rolled on wet and cures into a seamless, flexible membrane. The two main types we use are PMMA (a fast-curing resin) and polyurethane coatings. Because it’s applied as a liquid, it forms a continuous layer that moulds around even the most awkward shapes, with no joints at all.
What is single ply?
Single ply is a pre-formed PVC or TPO membrane laid over insulation, with the seams hot-air welded into one continuous skin. It’s fast to install over open areas, carries a long manufacturer guarantee and is the workhorse for most full flat roofs.
Both leave EPDM and GRP behind
It’s worth being clear why these are the two systems we work with. Single ply and liquid each solve the problem that undoes the cheaper alternatives:
- Single ply welds into a continuous skin, rather than relying on the adhesive joints that age and fail on EPDM.
- Liquid cures seamlessly around complex detailing, where rigid GRP would craze and crack as the structure moves.
So the real choice isn’t single ply versus rubber or fibreglass; it’s picking the right one of these two for your roof. For the wider comparison, see EPDM vs GRP vs single ply.
Where liquid roofing wins
- Complex detailing. Roofs crowded with pipes, plant, upstands and odd shapes, where a sheet membrane is fiddly, suit a liquid that simply flows around everything.
- Awkward or small areas. Balconies, gutters, dormers and tight junctions.
- Overlays and refurbishment. Liquid can often be applied over a sound existing surface to extend its life with minimal strip-out.
- Tie-ins. Sealing the join between a roof and surrounding details or upstands.
Where single ply wins
- Most full roofs. For open domestic and commercial roofs, welded single ply is fast, robust and excellent value.
- Larger areas. A welded sheet covers ground quickly with very few joints.
- All-weather installation. Single ply doesn’t depend on dry, warm curing conditions the way some coatings do.
How we choose, across Doncaster and South Yorkshire
We specify the system that fits your roof, its detailing and its access, rather than forcing one approach. Often that’s single ply; sometimes it’s a liquid system; occasionally it’s the two working together, with liquid sealing the tricky details. Either way, on roofs throughout Doncaster, Rotherham and Barnsley, you’ll get a straight recommendation and a clear written price.
Not sure which suits your roof? Get a free quote or call us on 07973 436 305.
Frequently asked questions
What is the difference between liquid roofing and single ply?
Single ply is a pre-formed membrane laid over insulation with hot-air welded seams, ideal for most full roofs. Liquid roofing is a resin or polyurethane coating painted on wet that cures into a seamless layer, ideal for complex detailing and awkward areas. Both form continuous waterproofing, unlike glued EPDM or rigid GRP.
Is single ply or liquid roofing better?
Neither is universally better; they suit different jobs. For most open domestic and commercial roofs, welded single ply is fast, robust and excellent value. For roofs crowded with pipes, plant and odd shapes, or for overlays, a liquid system can be the better tool. Often we use single ply with liquid sealing the trickiest details.
Do liquid and single ply beat EPDM and GRP?
For their respective uses, yes. Single ply welds into one continuous skin rather than relying on EPDM's adhesive joints, and liquid cures seamlessly around details where rigid GRP would crack. Both avoid the weak points that let rubber and fibreglass down.
Do you offer both liquid and single ply roofing in Doncaster?
Yes. We install single ply and liquid systems across Doncaster, Rotherham, Barnsley and the surrounding South Yorkshire area, specifying whichever suits your roof, its detailing and its access.