Lisburn at a glance
- Postcode districts
- BT17, BT26, BT27, BT28
- Population
- about 77,506 (GeoNames)
- Council area
- Lisburn and Castlereagh City Council
- Building approval
- Lisburn and Castlereagh City Council building control
- Nearest main town
- Belfast, about 7 miles
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
What does a balcony or terrace in Lisburn need?
Owners of flats in Lisburn sometimes find that a neighbour's balcony is leaking into their home. Where a balcony serves one flat but sits over another, the repair needs proper waterproofing and drainage, and a clear written specification helps everyone involved agree the work.
Around Lisburn, flat roofs are common on shops with flat-roofed rear stores below flats and on lock-up garage blocks on estates. Northern Ireland averages roughly 1,150 mm of rain a year, spread over many wet days, so a roof that sheds water quickly to clear outlets lasts far longer than one that holds puddles.
How much does balcony or terrace waterproofing cost in Lisburn?
Guide price in Lisburn: £1,650–£2,850 for a 12 m² balcony in a liquid-applied system including scaffold, including VAT at Northern Ireland 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 | £1,650–£2,850 |
| Single garage (18 m²), EPDM rubber | £1,400–£2,450 |
| Extension (20 m²), GRP, new deck + insulation | £2,650–£4,750 |
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.
What's included?
- Lifting and setting aside of existing paving or decking
- Written workmanship guarantee, with approvals handled where needed
- Free survey of the deck, falls, outlets and door thresholds
- Sealed details at doors, outlets, walls and balustrade posts
Building control in Northern Ireland
In Northern Ireland, Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where that's feasible. The district council's building control should be contacted before work starts, and we prepare the details it asks for. More on the rules.
Which nearby areas do we also cover?
Balconies and roof terraces in Lisburn: questions
Do you cover Lisburn?
Yes. Lisburn is part of our County Antrim coverage, including postcode districts BT17, BT26, BT27, BT28. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Lisburn?
Where the work needs approval it goes to Lisburn and Castlereagh City Council building control. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does balcony or terrace waterproofing cost in Lisburn?
£1,650–£2,850 for a 12 m² balcony in a liquid-applied system including scaffold, at Northern Ireland guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
How long does balcony waterproofing last?
It depends on the system and how well it is protected. As indicative ranges, liquid-applied systems last 10–25+ years by product and mastic asphalt 30–60, with good maintenance.
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.