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Feltham · Greater London

Damp investigation after cavity insulation in Feltham

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. We cover Feltham and the wider TW14 postcode district, and the price is confirmed before anyone visits.

Book a damp investigation in Feltham

Covering Feltham and the TW14 district. 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 for Feltham properties

Feltham is among the towns we cover in Greater London, alongside Hanworth, Hounslow and Hampton. It is roughly 13 miles west of London.

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

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.

In terms of approvals, if cavity wall insulation follows in Feltham, filling a cavity is notifiable building work and needs a building notice or competent-person self-certification.

Rules in England

Filling a cavity is notifiable building work and needs a building notice or competent-person self-certification if insulation work follows.

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 in Feltham

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

Guide prices for Feltham

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 Feltham:

  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 Feltham: questions

How much does a damp investigation cost in Feltham?

Guide prices are shown on this page, and the price for your Feltham property is confirmed before you book.

Do you cover Feltham?

Yes. Feltham and the TW14 postcode district are within our Greater London coverage, along with nearby Hanworth and Hounslow.

Do you cold-call in Feltham?

No. We only come out when you have asked us to. If someone cold-calls offering free insulation, check before you agree to anything.

Is there VAT on a damp investigation in Feltham?

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.

Nearby towns

Book a damp investigation in Feltham

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