A flat roof replacement strips the old covering from a low-pitched roof and lays a new waterproof system, usually EPDM rubber, GRP fibreglass or torch-on felt, over a sound deck with correct falls, upstands, trims and outlets so rainwater drains away.
For a homeowner in Johnstone, planning a new flat roof tends to begin with two questions: what will it cost, and how disruptive will it be? Our guide range is £1,900–£4,300 including VAT, and a typical job runs to 1–3 days for most roofs. Both numbers firm up once we have seen the property, measured up and agreed exactly what is included.
- Guide price
- £1,900–£4,300 inc VAT
- Time on site
- 1–3 days for most roofs
- Postcodes
- PA5
- Planning rules
- Scotland
- Local area
- Renfrewshire
- Survey
- Free, with a written quote
Flat roofs prices in Johnstone
The table below shows guide prices for a new flat roof in Johnstone. They are based on rates in Scotland, which run about 4% below the national guide, giving an overall range of £1,900–£4,300. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Johnstone |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £750–£1,900 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £1,900–£4,300 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £3,800–£8,600 |
The main things that change the figure:
- Roof area and access to the roof
- Covering system: EPDM, GRP or torch-on felt
- Condition of the deck and joists underneath
- Number of rooflights, pipes and upstands to detail
What does the job include in Johnstone?
- Survey of the covering, deck, falls, upstands and drainage
- Stripping and disposal of the old roof covering
- Replacement of rotten or soft deck boards
- Insulation upgrade to a warm roof build-up where agreed
- Upstands, flashings and drip edges finished neatly
- New trims, outlets and gutter connections
Local housing and a new flat roof
Paisley has sandstone tenements and terraces from its textile era, Greenock and Port Glasgow have tenements and housing climbing the hills above the Clyde, and Gourock and Kilmacolm have Victorian villas. Post-war estates and newer private housing surround the towns, and roughcast is a common finish.
Inverclyde is one of the wettest parts of lowland Scotland, and homes facing the Firth of Clyde take wind and driving rain.
If your house in Johnstone fits one of these patterns, it helps us anticipate what a new flat roof will involve, though we always confirm the details on site.
Do you need permission in Johnstone?
For anyone in Johnstone, the relevant framework is Scotland's. The summary below is general, so we always contact the council about your address before putting a price in writing.
In Scotland, like-for-like re-roofing does not usually need planning permission, except on listed buildings or in conservation areas.
Like-for-like re-covering does not usually need a building warrant, but structural changes or new roof windows can. Bats are protected across the UK; if they roost under roof tiles, soffits or fascias, work stops and a licensed ecologist advises before it restarts.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
The four stages
A visit to your home
A free survey comes first. It gives us what we need to price a new flat roof properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Price and scope agreed
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Dates and permissions
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
The work itself
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
What you can expect from us
Questions about a new flat roof in Johnstone
Should I insulate my flat roof when it is replaced?
Replacing a flat roof is the most cost-effective time to add insulation, because the covering is already off. A warm roof, with insulation laid above the deck, keeps the structure warm and reduces condensation risk. Building regulations may require insulation when a large part of the roof is renewed. It raises the roof height slightly, which affects trims and upstands.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Can you repair my flat roof instead of replacing it?
A flat roof can often be repaired if the damage is limited to a small split, a failed joint or a loose upstand and the rest of the covering is sound. If the deck is soft, the covering is blistered or cracked across the roof, or leaks keep returning, replacement is usually better value. We assess the whole roof and give you an honest recommendation.
Which is better, EPDM rubber or GRP fibreglass?
EPDM rubber and GRP fibreglass are both reliable modern flat roof systems. EPDM is a single flexible sheet with very few joints, which copes well with movement and suits most extensions and garages. GRP is a hard, seamless finish that copes better with foot traffic and complex shapes, but needs dry weather to apply. Felt costs less but usually lasts less long. We recommend a system after seeing your roof.
Can you combine a new flat roof with other work?
Yes. Because we manage several trades under one contract, we can plan a new flat roof alongside other work on your Johnstone home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Also covering areas around Johnstone
If your address falls within PA5, we cover it. The same goes for neighbouring Paisley, Barrhead and Erskine, which we include alongside Johnstone when arranging surveys and quotes.

