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Balconies and roof terraces in Chertsey

A leak under a balcony in Chertsey 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

Chertsey at a glance

Postcode districts
KT16
Population
about 15,967 (GeoNames)
Council area
Runnymede Borough Council
Building approval
Runnymede Borough Council building control, or a registered building control approver
Nearest main town
Woking, about 5 miles
Guide price region
South East (+10% on West Midlands rates)

What does a balcony or terrace in Chertsey need?

Balconies in Chertsey are often re-waterproofed when the ceiling below starts to stain. On many older balconies, the membrane was laid under tiles or screed with no way to inspect it, so by the time the leak appears, water may have been tracking under the surface for a long time.

In and around Chertsey, flat roofs are typically found on 1960s and 1970s link-detached houses with flat-roofed garages and porches, and on lock-up garage blocks on estates. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain.

How much does balcony or terrace waterproofing cost in Chertsey?

Guide price in Chertsey: £2,100–£3,600 for a 12 m² balcony in a liquid-applied system including scaffold, including VAT at South East rates. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Balcony (12 m²), liquid-applied, scaffold£2,100–£3,600
Single garage (18 m²), EPDM rubber£1,750–£3,100
Extension (20 m²), GRP, new deck + insulation£3,300–£5,900

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?

  • Sealed details at doors, outlets, walls and balustrade posts
  • Written workmanship guarantee, with approvals handled where needed
  • New liquid, GRP, single-ply or asphalt waterproofing
  • Lifting and setting aside of existing paving or decking

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 Chertsey: questions

Do you cover Chertsey?

Yes. Chertsey is part of our Surrey coverage, including postcode districts KT16. 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 Chertsey?

Where the work needs approval it goes to Runnymede Borough Council 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 Chertsey?

£2,100–£3,600 for a 12 m² balcony in a liquid-applied system including scaffold, at South East 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.

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.

Other flat roof work in Chertsey

Balconies and roof terraces in Chertsey: get a fixed price

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

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