Based in Crick | South Wales & West of England
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Grey liquid-waterproofed balcony beside brick walls and white patio doors. AI-generated illustration, not an LMB project.

Balcony & Terrace Waterproofing in Crick

Stop water getting into the rooms below with a fully bonded, seamless liquid or GRP membrane. Free survey and tailored quote.

10–20 year installation guarantees, depending on system and matting

The service

What balcony & terrace waterproofing involves

Balconies and terraces are flat roofs that people walk on. They often sit directly over living space, and they're full of details: door thresholds, balustrade fixings, drainage outlets and wall junctions. Each is a potential leak point.

Liquid roofing systems are particularly well suited to balconies and terraces because they flow around every detail and cure into a single, bonded membrane. GRP is also used where a rigid finish suits the space.

LMB is an approved liquid roof systems installer. The proposed waterproofing system and preparation requirements are confirmed following assessment.

Grey liquid-waterproofed balcony beside brick walls and white patio doors. AI-generated illustration, not an LMB project.

Who it's for

  • Homeowners with a balcony over a living room or bedroom
  • Owners of roof terraces and walkable flat roofs
  • Flats and apartment blocks with leaking balconies
  • Anyone creating a new balcony or terrace

When you need it

  • Water is appearing in the room below a balcony
  • The existing surface is cracked or lifting
  • Water pools near door thresholds
  • A new balcony or terrace needs waterproofing

Why use a specialist? Flat roofs fail at details: upstands, edges, outlets and joints. LMB focuses only on GRP and liquid roofing; the survey considers these details before work is specified.

If it's ignored

What waiting really costs

A leaking balcony or terrace sends water straight into the room below, and the many fixings and thresholds make the source hard to find without experience.

Damage below

Ceilings and walls under a balcony take the brunt of any leak.

Threshold failure

Water entering at door thresholds damages flooring and frames.

Structural decay

Persistent water can damage the balcony structure itself.

Unsafe surfaces

Deteriorating finishes can become a trip or slip hazard.

Common issues to avoid

  • Tiling over a balcony without a proper waterproof membrane
  • Sealing only the visible cracks
  • Poor detailing at door thresholds and balustrade fixings
  • Blocked or undersized drainage outlets

Our process

Five clear steps, start to finish

  1. Step 1

    Inspection

    Liam visits and inspects the covering, deck, edges, upstands, outlets and any penetrations. Free of charge.

  2. Step 2

    Diagnosis

    You get a plain-English explanation of what's wrong, what's causing it and the options: repair, overlay or replace.

  3. Step 3

    Written quote

    A tailored price for your roof with the system, scope and guarantee set out clearly. No fixed rates; any scope changes are discussed separately.

  4. Step 4

    Installation

    Preparation, deck repairs where needed, and the GRP or liquid system applied to the correct method in suitable weather.

  5. Step 5

    Check and guarantee

    Completed work checked and the applicable terms confirmed. Installation guarantees are 10–20 years, depending on the system and matting; repair terms must be agreed separately.

What you get

The benefits, in plain terms

Seamless seal

A continuous membrane with junctions specified for the assessed roof.

Detail-friendly

Flows around thresholds, fixings and outlets.

Approved installer

Approved liquid roof systems installer.

Long guarantee

10–20 years for installations, depending on system and matting.

Free survey

No-cost inspection and written quote.

Insured

£5 million public liability cover.

In detail

Balcony & Terrace Waterproofing: materials, methods and options

Waterproofing details that matter

On a balcony or terrace, the open surface is rarely where leaks start. Door thresholds, wall upstands, balustrade fixings and outlets are the critical points. A liquid membrane is dressed up and around each of these, forming a continuous seal with no laps.

Walkable finishes

Balconies and terraces need a surface that handles regular foot traffic. The right system and finish will be specified during the survey based on how the space is used.

Residential and multi-unit buildings

We waterproof single balconies on houses as well as balconies and terraces on flats and commercial buildings, planning work to minimise disruption to residents.

Where we work

We carry out balcony & terrace waterproofing from our base in Crick, near Chepstow, across Bristol, Bath, Newport, Chepstow, Somerset, Gloucestershire, Caldicot, Monmouthshire, Cwmbran, Thornbury, Portishead, Weston-super-Mare, Magor, Usk, Pontypool, Lydney, Keynsham, Clevedon, Yate, Bradley Stoke. See the areas we cover.

Why a specialist

Why choose a GRP and liquid only roofer

Many roofers offer every type of flat roof covering: felt, rubber, asphalt and fibreglass. LMB deliberately doesn't. We work only with GRP fibreglass and approved liquid roofing systems, because both create a single, seamless waterproof surface with properly specified junctions and details.

That focus shapes every recommendation we make for balcony & terrace waterproofing. We aren't trying to sell you whichever product we happen to stock. We're choosing between two modern systems on the basis of what your roof actually needs: its size, shape, deck condition, drainage, details and how it will be used.

Liam Brinkworth owns and runs the business. Contact Liam to discuss the survey, proposed work and quotation.

LMB holds £5 million public liability insurance. Liquid systems are applied as an approved installer, and installations come with a guarantee of 10 to 20 years depending on the system specified and whether it requires matting.

What affects the price of balcony & terrace waterproofing? The main factors are the roof area, how easy it is to reach, the condition of the existing deck, how many details there are (pipes, vents, rooflights, upstands and outlets), whether the old covering needs stripping, and which system is specified. That is why we never quote a fixed rate. The free survey looks at each of these on your roof, so the written quote reflects the real job and the proposed scope is clear. Any changes should be discussed before additional work is agreed.

Before you call

How to check your flat roof safely

You don't need to climb onto a roof to spot most warning signs. From an upstairs window, the garden or the ground, look for cracked or blistered surfaces, moss or vegetation growing on the roof, water that stays ponded for days after rain, lifted or broken edge trims, and gaps where the roof meets a wall.

Inside, check the ceilings under the flat roof for brown stains, bubbling paint or plaster, and any damp or musty smell. Stains that grow after heavy rain are a clear sign water is getting in, even if you never see a drip.

If you can, take a few photos and note when the problem appears: after every shower, only in heavy rain, or only in wind-driven rain. That detail helps narrow down the cause before the survey and makes your free quote more accurate.

Please don't climb onto or walk on a roof to inspect it. A soft deck can give way, and wet roofs are slippery. Leave that part to us. If water is actively coming in, call us for an emergency call-out rather than waiting.

Ready to get it looked at? Request your free survey or go back to the homepage.

Questions

Balcony & Terrace Waterproofing FAQs

Why is my balcony leaking into the room below?

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Often the cause is at a threshold, upstand, fixing or outlet rather than the open surface. The survey traces the source.

Is liquid waterproofing suitable for balconies?

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Yes. It flows around details and cures into one bonded membrane, which suits balconies well.

Can I walk on it afterwards?

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Only if the system, finish and supporting structure are suitable for the intended foot traffic. Suitability is assessed separately; do not assume every membrane is a walking surface.

What guarantee is included?

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10–20 years for installations, depending on the chosen system and matting; repair terms are separate.

How long does it take?

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It depends on the size, preparation and weather. The quote will confirm.

Do you work on flats?

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Yes, both houses and multi-unit buildings.

How much will it cost?

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We're strictly quote-only. Every roof differs in size, access, condition and detailing, so a fixed rate would not reflect the work needed on your property. The survey and written quote are free, so you'll know the exact cost before you commit to anything.

Are you insured?

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Yes. LMB holds £5 million public liability insurance.

Do you cover my area?

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We cover Bristol, Bath, Newport, Chepstow, Somerset and Gloucestershire from our base in Crick, near Chepstow. If you're nearby and unsure, call and ask.

All flat roofing services

Grey seamless flat-roof edge, gutter and brick wall in a UK residential setting. AI-generated illustration, not an LMB project.

Discuss your balcony waterproofing.Get a free survey.

Free survey. Tailored written quote. £5m public liability insurance. Approved liquid installer. Installation guarantees of 10–20 years, depending on system and matting.

07517 190213Free Quote