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Greater London · England

Damp investigation after cavity insulation in Greater London

A damp investigation finds out why an insulated wall is showing damp or mould: rain getting in through defects, bridged or wet fill, debris in the cavity, a breached damp-proof course, or condensation. Our Greater London coverage includes London, Islington, Bexley and the towns around them.

Moisture meter held against a damp, mould-spotted corner of an external wall indoors

Book a damp investigation in Greater London

Tell us about the property. We confirm the price before you book.

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We use your details only to answer this enquiry and arrange your visit, sharing them only with the registered installer we appoint for your job and the providers named in our privacy notice. No marketing lists, no cold calls.

Damp investigation after cavity insulation across Greater London

We cover 81 towns in Greater London, including London, Islington, Bexley, Barking, Archway and more.

Wind-driven rain is the first thing the surveyor weighs up. Much of Greater London sits in the more sheltered driving-rain zones of the UK, which widens the choice of fill. Exposed elevations, coastal sites and high ground still get checked wall by wall.

We never cold-call in Greater London or anywhere else, and we do not work with doorstep claims companies. Damp in an insulated Greater London home is not always the insulation's fault, so the diagnosis comes before any extraction.

Building Regulations in England

Filling an existing cavity wall is notifiable building work in England. Either a building notice goes to building control before the work, or the installer self-certifies it through a government-approved competent person scheme such as CIGA's CWISC scheme. The insulation used must also be suitable for the wall it goes into, which is why the survey checks construction, condition and exposure first.

Sources: Planning Portal: cavity wall insulation and building regulations; CIGA: CWISC competent person scheme.

Common causes we check

Defective pointing, cracked render and porous bricks letting rain in; leaking gutters and downpipes; fill bridging the cavity where mortar droppings or debris have collected; ground levels above the damp-proof course; and condensation from cooking, drying clothes and too little ventilation.

What is included

  • Moisture mapping inside
  • External defects check
  • Borescope at affected areas
  • Cause and options in writing

Damp investigation after cavity insulation prices in Greater London

Damp investigation after cavity insulation guide prices
Damp investigation after cavity insulation guide pricesGuide price
Damp investigation with borescope£295–£495

This work is not insulation, so it is normally standard-rated for VAT. Guide prices include VAT where it applies. Guide ranges only: the fixed price is confirmed in writing before any work starts, and anything that could not be seen at survey is agreed with you first.

The steps for a damp investigation in Greater London:

  1. Tell us what is happening

    Postcode, property type and what you have noticed.

  2. Price agreed first

    We confirm the price before anyone visits.

  3. Visit and checks

    Photos and readings at the areas that matter.

  4. Findings in writing

    What we found and the options, each priced separately.

Last reviewed 19 October 2026.

Damp investigation after cavity insulation in Greater London: questions

Do you cover all of Greater London?

Yes. We cover 81 towns across Greater London, including London, Islington, Bexley and Barking, and the villages around them. Island and remote addresses are surveyed by arrangement.

Is there VAT on a damp investigation in Greater London?

Damp investigation after cavity insulation is not insulation, so it is normally charged at the standard rate of VAT. The VAT treatment is confirmed on your quote.

What will I get from a damp investigation in Greater London?

A visit at an agreed price, photos of what we find, and a written summary in plain English. Any follow-on work is priced separately so you can choose who does it.

Will you tell me if I do not need any work?

Yes. If the findings show nothing needs doing, or a cheaper fix such as clearing a gutter will do, we say so.

Damp investigation after cavity insulation in nearby areas

Book a damp investigation in Greater London

Priced before you book. Findings in writing. No cold calls.