Cavity Wall and Retrofit Insulation Insurance

Almost every cavity wall insulation claim is really a complaint about the decision to fill, not about how the filling was done.

The factors that make a property unsuitable are knowable in advance: exposure to driving rain, a defective or permeable outer leaf, cracked render, failed pointing, inadequate cavity width, debris or mortar snots bridging the cavity, and construction types the system was never intended for. An assessor instructed years later will look at the property and at your survey, and the question will be whether a competent surveyor should have declined.

Which makes the survey record the single most valuable asset the business has. Record the exposure rating, the condition of the outer leaf with photographs, the cavity width and what the boroscope showed, the construction type, and crucially the reason for proceeding. Where a property is marginal and the customer wants it filled anyway, a signed record that you advised against it is worth more than any wording. And where it is genuinely unsuitable, declining is cheaper than the claim.

This is the trade on the site where stopping work does not stop the exposure, and it catches businesses at exactly the wrong moment.

Installations from a decade ago are still generating claims, and a business that winds down, is sold, or simply stops installing and moves into something else remains the party that filled those cavities. If the cover stops on the last day of trading, there is nothing behind any of it, and claims will keep arriving regardless.

So run-off has to be part of the plan rather than an afterthought, and the question is worth asking now rather than at the end: how long, at what cost, and whether the insurer will offer it at all. It also makes continuity while trading more important than price. A gap of a month on a claims made policy can strand years of completed work, which is a far larger problem than whatever the saving was.

Unlike most trades, the volume of claims here is driven partly by marketing rather than purely by failures.

Claims management companies advertise directly to homeowners, bring batches of claims against installers and scheme guarantees, and are not deterred by weak cases because the economics work on volume. That means an installer can face a stream of claims where some are well founded, some are marginal and some are without merit, and all of them cost something to assess and respond to.

Two consequences follow. The administrative load is real, so legal expenses and a policy with competent claims handling behind it are worth more here than in a trade with occasional claims. And good records are the defence across the whole batch rather than case by case: an installer with surveys, photographs, boroscope records and signed customer declarations for every property can resolve most of a batch quickly, while one without them is negotiating in the dark on all of them.

Firms moving from cavity fill into external wall insulation are taking on something materially different, and the policy frequently has not been told.

External systems involve fixing a render carrier and insulation to the face of a building, working at height across the whole elevation, scaffold, and a finish that has to shed water for decades. The failure modes are cracking, delamination, water tracking behind the system and damage to the substrate, and the remedy is removing and replacing an entire elevation rather than extracting bead from a cavity. There is also a fire performance dimension on anything above a certain height, which has become far more scrutinised.

So declare it specifically with a turnover split, keep the system manufacturer's specification and training records, and be careful about buildings where height brings fire performance requirements into play. A policy written for cavity fill has priced a very different job.

The long tail and the claims industry make this trade unlike any other installation risk. We are an FCA regulated broker and will not tell you we are the best choice. These are the questions that decide it.