Flat roofing specialists · Bromley, Kent & London
A waterproof, anti-slip surface you can actually use, with thresholds, drainage and upstands resolved so water leaves the balcony instead of ending up in the room below. Free fixed-price quotation and a 10-year workmanship guarantee.
16 years in flat roofing · trafficked systems · fully insured
Overview
Balcony and walkway waterproofing is flat roofing that has to survive being walked on. We use reinforced liquid systems with anti-slip finishes and, where appropriate, single-ply with walkway membrane, over a build-up detailed for thresholds, drainage and the balustrade fixings that penetrate it.
Homeowners with a balcony or roof terrace over a habitable room, flat owners and freeholders with communal access walkways and decks, managing agents responsible for block balconies, and commercial clients with roof terraces and plant access routes.
When water is appearing in the room or hallway beneath, when the existing surface is cracked, lifting, chalky or slippery, when a balustrade has been refixed through the waterproofing, or when a balcony is being built or refurbished as part of wider works.
Balconies concentrate every hard problem in flat roofing into a small area: a door threshold that is often too low, tight falls, a perimeter upstand at the balustrade, penetrations from posts and fixings, and constant foot traffic on the finished surface. A domestic-grade coating will not survive that, and a sheet system alone will not wrap the details. The solution has to be specified for use, not just for waterproofing.
What happens if it is left
Balconies sit over habitable space. A failure here does not show on a garage ceiling, it shows on a bedroom ceiling, along with the plaster, decoration and joinery around it.
Where the door threshold sits level with or below the balcony surface, heavy rain and blocked drainage push water under the door line. It is the single most common balcony defect and it will not be solved by another coat of anything.
Balcony decks that stay wet degrade, and on a raised structure that becomes a safety issue rather than a maintenance one.
Worn, smooth or algae-covered walkway surfaces in blocks are a liability for the freeholder and managing agent as well as a nuisance for residents.
Our process
We check the deck, falls, outlet, threshold height, balustrade fixings and the existing surface, and look at what is happening in the space below.
We establish whether the failure is the surface, the details or the drainage, then specify a trafficked build-up and finish for how the balcony is actually used. Free fixed-price quotation.
Existing failed surfaces removed, deck repaired, drainage corrected or upgraded, and threshold arrangements resolved where the design allows.
Reinforced liquid system applied and fully detailed around posts, upstands and thresholds, with an anti-slip aggregate finish, or single-ply with walkway membrane where that suits better.
Surface cured and checked, drainage tested, area left clean, and the work covered by a 10-year workmanship guarantee.
What you get
Anti-slip finishes designed for regular foot traffic, including communal walkways in blocks.
Reinforced liquid wraps balustrade posts, upstands and thresholds in a continuous membrane with no joints to fail.
We deal with the door line and the drainage together, because fixing one without the other does not stop the leak.
The point of the work is that the ceiling underneath stays dry, permanently, not until the next storm.
Cold-applied, no hot works, and usually completed in a short programme with the property in use.
A 10-year workmanship guarantee, quoted at a fixed price before we start.
In detail
The top coat on a balcony is doing two jobs: protecting the waterproofing from wear and giving grip in the wet. Anti-slip aggregate is broadcast into the resin and sealed, producing a durable textured surface. Finish choice takes account of how the balcony is used, a communal escape route in a block needs a different specification from a private balcony with two chairs on it.
Adequate height between the finished balcony surface and the door threshold is what keeps water out, backed up by drainage that removes water before it can build. Where existing thresholds are too low, options include a threshold drain or channel, relocating and upsizing outlets, and adjusting the finished level within what the structure allows. We identify what is achievable at survey rather than promising it blind.
Every balustrade post that passes through the waterproofing is a potential leak. Posts are detailed individually with reinforcement dressed and sealed around the base, and where possible we prefer arrangements that fix into the upstand or fascia rather than through the horizontal surface. Refixing a balustrade after waterproofing without re-detailing is one of the fastest ways to undo the work.
Roof terraces sometimes carry paving on pedestals or a tiled finish over the waterproofing. The waterproofing beneath still has to be a complete, fully detailed system with functioning drainage, decorative surfaces are not waterproofing, and any drainage layer below them has to reach an outlet.
Access decks and walkways in blocks of flats take heavy footfall, need to stay usable during the works, and often have to be phased so residents keep access. Anti-slip specification, edge and upstand detailing, and outlet capacity are the priorities. RAMS are provided for the works and photographic reporting can be supplied to managing agents.
Where a roof is walked for plant maintenance, we specify a defined walkway route so traffic is not wearing the field membrane, protecting the roof and giving maintenance staff a marked path. On commercial sites we work to RAMS and are asbestos awareness trained for older buildings.
Common questions
Every balcony is quoted individually, size, deck condition, threshold and drainage work and balustrade detailing all affect it. Quotations are free and fixed price as standard, with no 'from' prices.
Most single balconies are a short job of a few days, allowing for cure times between coats. Communal walkways in blocks are phased so access is maintained. Timings are confirmed in the quotation.
That is exactly the work. We inspect the surface, threshold, drainage and penetrations to identify the actual entry point rather than recoating and hoping.
No: trafficked areas are finished with an anti-slip aggregate specified for how the balcony or walkway is used.
The finish usually has to come up so the waterproofing can be applied to a properly prepared substrate and detailed at the edges. Paving on pedestals can often be lifted and relaid over the new system.
Often, yes, through threshold drainage, upgraded outlets or adjusting finished levels within what the structure allows. We assess it at survey and tell you what is realistically achievable.
A correctly prepared and reinforced trafficked system is a long-life surface. Wear depends on footfall and maintenance, and we back the workmanship for 10 years.
Yes, on communal balconies and walkways, with RAMS provided and photographic reporting available for records and service charge documentation.
Bromley, Kent, London and the South East, including Orpington, Beckenham, Croydon, Dartford and Sevenoaks.
Tell us about the roof and your postcode. We will inspect it, tell you what has actually failed and give you a fixed price, backed by a 10-year workmanship guarantee.
16 years in flat roofing · Sika, Danosa and Bauder trained · fully insured · 10-year workmanship guarantee