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Balconies and roof terraces in Bexley

A leak under a balcony in Bexley usually shows up as a stain on the ceiling below, but the cause is often at the door threshold or an outlet. We trace it at survey, then waterproof the whole balcony properly rather than sealing one spot and hoping for the best.

London roof terrace with porcelain paving on pedestals over a waterproofed flat roof and a glass balustradeComputer-generated example image

Bexley at a glance

Postcode districts
DA6, DA7, DA5, DA8, DA16, DA17, DA15, DA18 and 1 more
Council area
London Borough of Bexley
Building approval
London Borough of Bexley building control, or a registered building control approver
Guide price region
London (+20% on West Midlands rates)

What does a balcony or terrace in Bexley need?

Door thresholds are a common reason for balcony work in Bexley. Where a door was fitted with a low step-out and no drainage channel, water driven against the frame finds its way under the sill. Re-waterproofing gives the chance to rebuild that detail properly.

In and around Bexley, flat roofs are typically found on kitchen extensions and roof terraces behind period houses, and on mansard and dormer loft conversions. The Thames basin is one of the drier parts of Britain at roughly 730 mm of rain a year, but summer heat is the bigger test here: dark membranes on south-facing roofs swing a long way in temperature.

How much does balcony or terrace waterproofing cost in Bexley?

Guide price in Bexley: £2,300–£3,900 for a 12 m² balcony in a liquid-applied system including scaffold, including VAT at London rates. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Balcony (12 m²), liquid-applied, scaffold£2,300–£3,900
Single garage (18 m²), EPDM rubber£1,900–£3,350
Extension (20 m²), GRP, new deck + insulation£3,600–£6,450

How long does it take to waterproof a balcony?

A small balcony is typically waterproofed in two to four working days, plus time for scaffold if it is above ground floor. Liquid and GRP systems need dry weather and cure time between coats, which sets the pace.

The balcony door will be out of use while the membrane is laid and curing, and the room behind may be noisy while old paving or screed is broken out. If the team needs to work through the house, we agree a route and protect floors. Larger terraces with paving or decking take longer, because the finish has to be lifted and reinstated. Resin systems smell while they cure, so nearby windows are best kept closed.

What's included?

  • New liquid, GRP, single-ply or asphalt waterproofing
  • Lifting and setting aside of existing paving or decking
  • Strip-out of the failed membrane and deck repairs
  • Written workmanship guarantee, with approvals handled where needed

Building regulations in England

Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.

Which nearby areas do we also cover?

Balconies and roof terraces in Bexley: questions

Do you cover Bexley?

Yes. Bexley is part of our London coverage, including postcode districts DA6, DA7, DA5, DA8, DA16, DA17 and 3 more. 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 Bexley?

Where the work needs approval it goes to London Borough of Bexley building control, or a registered building control approver. 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 Bexley?

£2,300–£3,900 for a 12 m² balcony in a liquid-applied system including scaffold, at London guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

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.

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.

Other flat roof work in Bexley

Balconies and roof terraces in Bexley: get a fixed price

Free survey and a written fixed quote for replacement and new roofs. No obligation.

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