- Guide price
- £1,800–£3,100
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Lancashire at a glance
- Largest towns
- Preston, Burnley, Blackburn, Blackpool
- Postcode areas
- BB, FY, L, LA, OL, PR, WN
- Building control
- Preston City Council, Burnley Borough Council, Blackburn with Darwen Borough Council and 10 other councils
- Neighbouring areas
- Greater Manchester · Merseyside · Cheshire · West Yorkshire
- Guide price region
- North West (−5% on West Midlands rates)
How much does balcony or terrace waterproofing cost in Lancashire?
Guide prices including VAT at North West rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Balcony (12 m²), liquid-applied, scaffold | £1,800–£3,100 |
| Single garage (18 m²), EPDM rubber | £1,500–£2,650 |
| Extension (20 m²), GRP, new deck + insulation | £2,850–£5,100 |
Which flat roofs are common in Lancashire?
Flat roofs in Lancashire sit on bungalows with flat-roofed side extensions and dormers, shops with flat-roofed rear stores below flats and 1930s semis with flat-roofed garages and kitchen extensions. The North West is one of England's wetter regions, averaging roughly 1,290 mm of rain a year, so falls, outlets and well-detailed upstands matter more than the membrane colour. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in England
Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. Renovated roofs over heated rooms are insulated to around 0.16 W/m²K where that's feasible, and new extension roofs are built to 0.15 W/m²K. In Lancashire the application goes to Preston City Council, Burnley Borough Council, Blackburn with Darwen Borough Council and 10 other councils. More on the rules.
How are thresholds, drainage and paving handled on a terrace?
They are designed together, because most balcony leaks start at the door threshold, a blocked outlet or a fixing driven through the membrane. Getting those three right matters more than the brand of membrane.
Thresholds: upstands are usually 150 mm above the finished surface, but a level or low step-out door cannot always achieve that. Where the upstand has to be reduced, extra protection is needed, such as a drainage channel at the door and a fall away from it, and the membrane must still run up and under the door sill.
Drainage: every terrace needs a reliable way off for water, with outlets sized for the area and an overflow if one outlet could block. Outlets under paving need access for cleaning.
Inverted roofs and pedestals: on an inverted roof the insulation sits above the waterproofing and is held down by paving or ballast, protecting the membrane from sun and foot traffic. Adjustable pedestals lift paving slabs level above the falls, so water drains underneath and the surface stays flat. Balustrade posts are fixed through upstands or side-fixed where possible, with every penetration sealed into the membrane.
Do I need planning permission for a balcony or roof terrace?
For a new balcony or roof terrace, generally yes. In England, balconies and raised platforms are not permitted development for houses, so a planning application is normally needed, and the other nations have their own rules.
Re-waterproofing an existing, approved balcony that looks the same afterwards does not normally need planning. Building regulations are a separate question. A terrace over a heated room is a thermal element, so replacing most of it can bring insulation requirements and approval. Turning a flat roof into a terrace also raises structural questions, because people, furniture and paving add load, and it needs guarding, such as a balustrade, that meets the regulations. A structural engineer should confirm that the roof can carry the new use.
Listed buildings and conservation areas add another layer of control. Our building regulations page covers approvals, and our planning permission guide covers the planning side.
Which towns in Lancashire do we cover?
- Preston
- Burnley
- Blackburn
- Blackpool
- Morecambe
- Lancaster
- Lytham St Annes
- Skelmersdale
- Leyland
- Accrington
- Chorley
- Darwen
- Thornton-Cleveleys
- Nelson
- Fleetwood
- Ormskirk
- Rawtenstall
- Colne
- Poulton-le-Fylde
- Heysham
- Haslingden
Balconies and roof terraces in Lancashire: questions
Which towns in Lancashire do you cover?
All of Lancashire. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does balcony or terrace waterproofing cost in Lancashire?
£1,800–£3,100 for a 12 m² balcony in a liquid-applied system including scaffold, at North West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in Lancashire?
All of Lancashire, including the BB, FY, L, LA, OL, PR, WN postcode areas. Send your full postcode and we'll confirm.
Why is water coming through the ceiling below my balcony?
The usual causes are a failed door threshold, a blocked or poorly sealed outlet, or a fixing through the membrane. A survey, sometimes lifting paving, finds the source.
Can I put decking straight onto my flat roof?
Not directly onto the membrane. Decking needs a supporting system that spreads the load and lets water drain, and the roof must be checked for the extra weight.
Do you install balustrades?
Our work is the waterproofing and drainage. We detail the membrane around balustrade fixings so they stay watertight, and we can advise on where posts should be fixed.
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