Cavity Wall Insulation Removal Company

Damp inside walls that were filled to keep you warm. A mortgage valuer who has written two lines about the insulation. If either is why you are here, the answer usually starts with a camera inside the cavity, and sometimes ends with the fill coming out.

Ask for a cavity survey

We introduce you to an independent extraction specialist. How our service works.

Fill has slumped, leaving an empty band at the top of the wall that runs cold.
Mortar droppings or debris on a tie make a bridge for water to cross.
Wet fill at the base holds water against the inner leaf.
Damp and mould show inside, often low down or around windows.
In exposed spots, wind-driven rain soaks right through the brick.

Section through a typical cavity wall, drawn to scale: 102 mm brick, a 65 mm cavity (most are 50 to 75 mm), 100 mm block, plaster.

Is it the insulation?

Tick what you are seeing. Some signs point at the cavity fill; others point somewhere cheaper to fix. Nothing here is sent anywhere.

Tick the signs that match your house.

Damp patches on the inside of outside wallsClassic sign of water crossing a bridged or wet cavity, especially if it is worst on one side of the house.
The damp started a year or two after the insulation went inTiming is one of the strongest clues. Write down both dates.
Black mould low on walls or around window revealsCold spots from slumped or missing fill, or wet fill at the base, encourage mould.
One wall is much worse, usually the one facing the weatherWind-driven rain soaks exposed brick; filled cavities in exposed spots are a known risk.
A valuer or surveyor mentioned the insulationTheir next question is usually for a guarantee or a specialist report.
Damp only in the bathroom or kitchen, worse in winterOften condensation. Ventilation and heating are worth checking first.
A tide mark up to about a metre from the floorCan be rising damp or bridged ground levels, though wet fill at the base can look similar.
Damp under a leaking gutter or downpipeFix the leak first; it may be the whole story.

The work, in the order it happens

Not every house needs every step. A survey decides; the guarantee decides who pays.

Cavity survey
A camera inside the wall says whether the fill has failed, and where.
£50 to £300, often free
Extraction
Bricks lifted at the base, fill blown loose and vacuumed out, cavity checked clear.
£20 to £30 per m²
Refill, or leave it empty
Bonded bead, mineral wool, nothing at all, or insulate another way.
£18 to £30 per m² for bead
Wall ties
Rusting ties found while the cavity is open, replaced with stainless.
£30 to £50 per m²

Paperwork rather than brickwork? Read about CIGA guarantee claims or what to do when a mortgage valuer flags it.

What removal costs

About £20 to £30 per square metre of wall to extract, before VAT. Party walls are not filled, so a mid-terrace has far less wall to clear than a detached house.

Work out your house

House	Wall to clear	Extraction	Extract and refill
Mid-terrace house	About 45 m², front and back walls only	£900 to £1,350	£1,700 to £2,700
Semi-detached house	About 80 m², front, back and one side	£1,600 to £2,400	£3,050 to £4,800
Detached house	About 120 m², all four walls	£2,400 to £3,600	£4,550 to £7,200
Semi-detached bungalow	About 50 m², three walls, single storey	£1,000 to £1,500	£1,900 to £3,000

Guide prices from published UK price guides (2024 to 2026), read November 2026. Refill priced with bonded polystyrene bead. Scaffold, wall ties and repairs extra.

Before you pay anyone

Look for a guarantee

Most fill installed under government and energy-company schemes came with one, and CIGA issued most of them. If the failure is down to the installation, the installer or guarantee provider should be your first call. GOV.UK’s consumer guide sets out the order: installer, then guarantee provider.

Ask why it failed

BRE guidance treats exposure to wind-driven rain as a principal risk for filled cavities, and Historic England warns that narrow early cavities let water cross. If your wall is one of those, refilling it the same way repeats the problem.

Know the VAT position

HMRC zero-rates installing insulation in homes until 31 March 2027. Removing it is not covered, so expect VAT on extraction and none on a refill done before that date.

Ignore the doorstep

Both the UK and Welsh governments warn about claims companies that cold call about cavity insulation. You can raise a concern with a guarantee provider yourself, for nothing.

Where our information comes from

How the job gets done

The specialist we match you with surveys, prices and carries out the work; any contract is between you and them.

Survey
Outside first (exposure, pointing, gutters), then a borescope through mortar joints on each wall.
Guarantee check
If the fill is guaranteed, the provider gets the first chance to put it right.
Extraction
One to three days for most houses, all from outside. Bricks relaid in matching mortar.
Dry, then decide
Weeks for a wet wall to dry. Refill the suitable walls; leave or treat the exposed ones differently.

Questions homeowners ask

Can cavity wall insulation be removed?

Yes. Specialists lift bricks along the base of each wall, loosen the fill with compressed air and draw it out with an industrial vacuum, checking with a borescope that the cavity is clear. Bonded beads and set foams take longer than loose fill.

How much does it cost to remove cavity wall insulation?

Published UK price guides put extraction at about £20 to £30 per m² of wall: roughly £1,600 to £2,400 for a semi-detached house and £2,400 to £3,600 for a detached one, before VAT. The removal cost calculator works it out by wall.

Does cavity wall insulation cause damp?

Properly installed in a suitable wall, it should not. Damp follows when the wall was unsuitable (very exposed, narrow cavity), the installation was poor (voids, no binder, debris left in the cavity) or the outer wall has let water in (failed pointing, gutters).

Will the guarantee pay for removal?

It may, if the failure comes from the installation or the materials. Go to the installer first, then the guarantee provider, before paying anyone. See CIGA guarantee claims.

How long does extraction take?

Published guides say one to three days for a whole house. A wet cavity then needs several weeks to dry before any refill.

My mortgage valuer flagged it. What now?

Read exactly what the lender is asking for: often a guarantee certificate or a specialist report, sometimes the work itself. See cavity wall insulation and your mortgage.

Tell us what the walls are doing

Three short steps. Your postcode, the house and what you are seeing are enough to start. The specialist confirms the detail with a borescope survey before any price is fixed.

Costs you nothing. We hold on to what you send until you have agreed to the extraction specialist we suggest.

Step 1 of 3

Where is the house?

Postcode