Flat Roofing inDundee, Perth & Fife —Watertight for 25+ Years.
PVC single-ply flat roofs with hot-air welded seams, installed to manufacturer specification and supplied with full-system manufacturer warranties. Garages, extensions, dormers and commercial — no more annual patch jobs, no more buckets in the loft.
PVC single ply · Manufacturer system warranties · Free survey
Flat Roofing — what it covers and when it's right.
Flat roofing covers any roof with a pitch under 10°. We install PVC single-ply only — a thermoplastic membrane with hot-air welded seams that routinely delivers 25–30 years of trouble-free service when correctly specified and installed.
Anyone with a garage, extension flat roof, dormer, porch or commercial flat roof at end of life — or anyone planning a new extension and weighing flat vs. pitched options.
When you see pooling water, blisters, splits, internal damp patches, or when the existing covering is over 20 years old. New-build extensions: spec the flat roof properly from day one and you'll never touch it again.
Flat roofs fail at details — upstands, edge trims, outlets, abutments — not in the middle of the field. DIY and generalist jobs nearly always fail at these points within 3–5 years. Installation by a roofing specialist to manufacturer detail is what unlocks the manufacturer system warranties that make flat roofing economic.
The cost of ignoring it always exceeds the cost of fixing it.
Pooling water
Standing water on a failed flat roof finds every micro-crack. Within one winter it's inside the building.
Internal damage
Flat roofs cover the rooms you actually live in — kitchens, extensions, bedrooms. A leak doesn't drip into a loft; it ruins plaster, flooring and electrics.
Structural deck rot
OSB and ply decks rot fast under failed coverings. Replacement triples the cost of a routine recover.
Warranty void
Manufacturer system warranties are void without certified installation. DIY install = no warranty cover, ever.
Common mistakes we get called to fix
Most of these started as someone trying to save a few hundred pounds.
- Patching repeatedly when a PVC single-ply recover would last 25+ years for similar lifetime cost
- Using mastic at upstands instead of proper bonded trims and welded detailing
- Installing in temperatures below manufacturer minimums (a real risk in Scottish winters)
- Skipping correct falls so water pools and overloads seams and outlets
A five-step system — no surprises.
Step 1 — Free survey
We assess existing deck condition, falls, outlets and abutments. Honest advice on recover vs. strip-and-replace.
Step 2 — Written quote
PVC single-ply specification, fixings method, trims and detailing — itemised in writing.
Step 3 — Strip and prepare
Old covering removed, deck inspected and replaced where rotten, falls corrected where needed.
Step 4 — System installation
Manufacturer-specified PVC single-ply membrane, hot-air welded seams, bonded or mechanically fixed to deck, all trims and outlets to manufacturer detail.
Step 5 — Inspection & warranty
Final inspection, water test, manufacturer system warranty registered in your name.
What you actually get when you hire Rossi.
Decades, not years
Properly installed PVC single ply routinely delivers 25+ years. The maintenance bill drops to zero.
Hot-air welded seams
Seams are fused, not glued — the membrane becomes one continuous sheet. No adhesive failure points.
Genuine warranties
Manufacturer system warranties — available where the system is installed to manufacturer specification.
Walkable systems available
Where you need access (terraces, balconies) we install protected PVC build-ups that take foot traffic without compromising waterproofing.
Clean, modern finish
Crisp edge trims, neat outlets — looks engineered, not patched. Adds visible quality to extensions and dormers.
No more patch-job spend
One done-right installation replaces a decade of in writing on request annual patches.
The materials, methods and variations behind flat roofing.
We install PVC single-ply membrane systems exclusively for flat roofing. Hot-air welded seams, manufacturer-detailed trims and a single material on every flat roof we touch — that consistency is why our flat roofs don't fail at detailing. Here's how we specify them.
Materials we use
- PVC single-ply membrane (Sika Sarnafil, Protan and equivalent manufacturer-approved systems) — thermoplastic, hot-air weldable, 25+ year design life
- Manufacturer-matched PVC trims, internal/external corners, outlet flanges and pipe collars
- Aluminium edge trims and kerb upstands engineered to last as long as the membrane
- OSB3 and exterior-grade ply decks where structural replacement is needed
- Stainless and approved fasteners for mechanically fixed installations
Methods we follow
- PVC single-ply membrane bonded or mechanically fixed to deck per manufacturer spec
- Seams hot-air welded with manufacturer-calibrated welders — fused membrane, not adhesive
- Upstands, parapets and abutments dressed in PVC with welded internal corners
- Outlets, pipe penetrations and rooflights detailed with manufacturer-matched preformed components
- Falls designed to BS 6229 (minimum 1:80) so water drains cleanly to outlets
Variations of this service
Garage flat roofs
Most common job — typically 12–25m². PVC single-ply install completed in one day, supplied with the manufacturer's warranty.
Extension flat roofs
Often integrated with rooflights and abutting house wall. PVC welds cleanly around rooflights and into vertical upstands.
Dormer roofs
Small but detail-heavy — abutments to tile, lead apron, vertical cheeks. PVC single ply or hand-dressed lead.
Balcony and terrace roofs
Walkable PVC build-ups with protection layers or paving on pedestals.
Commercial flat roofs
Larger areas, fall-arrest required, often phased to keep tenants operational. Mechanically fixed PVC single ply.
When it applies
Typical situations we're called for across Tayside and Fife.
- Garage and outbuilding recovers
- New build extension specifications
- Dormer waterproofing
- Commercial unit re-roofs
- Listed property porches and bay roofs where lead alternatives are too costly
Residential vs commercial
Residential and commercial flat roofs alike are installed in PVC single ply. Domestic jobs are usually one-day installs with bonded membrane; larger commercial roofs are mechanically fixed for handling and wind-uplift reasons, with CDM 2015 documentation included in the quote.
Answers, in plain English.
Something not covered? Phone 01738 260550 — answered by a roofer.
Every job is different — call us on 01738 260550 or send a quick message and we'll give you a written, no-obligation quote.
Often booked alongside flat roofing.
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Roof Repairs
Fast, made-good repairs that stop leaks and protect your home.
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Roof Replacement
Full re-roofs built to last decades, written quote and 25-year guarantee (including flat roofs).
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Emergency Roofing
Same-day emergency response for storm damage, leaks and make-safe call-outs.
Flat Roofing across Tayside & Fife.
Same service, same standards, same care in every town we cover.
Not sure if we cover you? Ask usGet a written quote for flat roofing — free, no obligation.
Free inspection as soon as we can. Written quote usually the same day as the visit. Phone answered by a roofer — no call centre, no chasing.