Group G · Airtightness, thermal bridging and finishing
Fire-stopping and cavity barriers
Cavity barriers and fire-stopping installed with EWI, cavity and loft works.
Priced after survey
Fire-stopping and cavity barriers
Every job like this is different, so we measure first and give you a fixed written quote. The price depends on:
- The area and access
- What's there now and its condition
- The system and finish you choose
No obligation — your survey confirms what suits and what it costs.
- Best for
- All EWI and blocks of flats
- Guarantee or standard
- Approved Document B
- Time on site
- Draught-proofing is usually done in a day.
- Typical price
- Priced after survey
What it is
What is fire-stopping and cavity barriers?
Cavity barriers and fire-stopping installed with EWI, cavity and loft works.
Best for: All EWI and blocks of flats.
Who it suits
Which homes is fire-stopping and cavity barriers suitable for?
Is my home suitable?
Pick your property type for a straight answer on fire-stopping and cavity barriers.
Guidance only — every home is different, and a survey confirms what suits yours.
Houses
- Detached house
- Semi-detached house
- End-of-terrace
- Mid-terrace
- Townhouse
- Mews house and cottage
- Detached bungalow
- Semi and terraced bungalow
- Chalet and dormer bungalow
- Period home
- 1930s home
- Post-war and ex-council house
- Non-traditional / system-built
- Listed building or conservation area
- Farmhouse, barn conversion or rural home
- New build or self-build
Flats and blocks of flats
Commercial and public buildings
Usually suitable Depends — a survey confirms
Not usually suitable for 1 property type
- Park and mobile home — Park and mobile homes need specialist systems, which we arrange through a partner rather than standard measures.
Materials and brands
What we use
Cavity barriers and fire-stopping installed with EWI, cavity and loft works.
Insulation brands we work with
- Knauf Insulation (Earthwool, Supafil blown)
- Rockwool
- Superglass
- Isover
- Kingspan
- Celotex
- Recticel
- Xtratherm
- Steico wood-fibre
- YBS and Actis multifoil
The exact system and brand for your home are confirmed in your written quote.
Heat, bills and EPC
What it does for your heat loss, bills and EPC
Draughts carry warm air straight out of a home, and thermal bridges create cold spots where heat bypasses the insulation. Sealing and fixing them reduces heat loss and makes rooms feel warmer, while controlled ventilation keeps the air healthy and the fabric dry.
See the EPC points and savings for your home in the EPC plannerU-value before and after, typical heat and bill saving, and EPC points — worked out for your property.Price
How much does fire-stopping and cavity barriers cost?
Priced after survey
Jobs like this vary too much for a fair online price, so we measure first and give you a fixed written quote — with no obligation.VAT on this work
Insulation installed in homes in Great Britain is zero-rated for VAT until 31 March 2027. Other parts of a job like this — such as a new roof covering, structural work or waterproofing — may be standard-rated. Your quote shows the split.What to expect
Time on site, disruption and approvals
Time on site
Draught-proofing is usually done in a day. Airtightness, thermal bridging and ventilation work is scheduled with the main retrofit.
Disruption
Low for draught-proofing; higher where floors, linings or ceilings are opened up.
Planning and building control
Ventilation must meet Building Regulations Part F, fire-stopping follows Approved Document B, and funded whole-house retrofit follows PAS 2035.
Guarantee and standard
Approved Document B. The guarantee and certification for your job are confirmed in writing in your quote.
60-second grant check
Could a grant help pay for it?
Grant eligibility checker
About 60 seconds · plain results: likely, possibly or not eligible
Before we start
What type of property is it?
Questions
Fire-stopping and cavity barriers: your questions answered
What are cavity barriers?
Fire-resistant barriers placed in cavities and at junctions to stop fire and smoke spreading through hidden voids.
When are cavity barriers needed?
With EWI, cavity and loft works, and on every block of flats project, to Approved Document B.
Do you install fire breaks on houses?
Yes — on EWI jobs, fire breaks at party walls and openings are part of the detailing wherever the system requires them.
Group G
More in airtightness, thermal bridging and finishing
Thermal bridging fixes
Insulated lintels, reveal and cill insulation and thermal breaks that stop cold spots and mould.
Airtightness works
Membranes, tapes, grommets and sealants at joints, service holes and floors.
Draught-proofing
Sealing doors, windows, letterboxes, hatches, floorboards and unused chimneys — every home's quick win.
Pipe, tank and cylinder insulation
Pipe lagging, cylinder jackets, radiator reflector panels and loft tank insulation.
Acoustic insulation
Sound insulation in floors, party walls and ceilings.
Ventilation with insulation
Trickle vents, extract fans, PIV or MVHR so a better-sealed home stays dry.
Begin your project
Ready to talk about fire-stopping and cavity barriers?
Tell us about your home and we'll arrange a survey, then a fixed written quote — no obligation.