Damp Proofing Guarantees in the UK: What Is Really Covered

A damp proofing guarantee is only as strong as three things: the written terms, the insurance behind it and the paperwork you hold. A contractor’s own guarantee depends on that contractor still trading. An insurance-backed guarantee (IBG) adds a policy that can step in if the contractor stops trading. Proofterior gives a 25-year insurance-backed guarantee on all treatment work, after a complimentary survey and a detailed written report that names the cause of the damp.

Key Takeaways

• A guarantee is a written promise from the installer. An insurance-backed guarantee adds a policy that protects you if the installer ceases trading.
• Exclusions matter more than the headline term. Lack of maintenance, later alterations, indirect losses, caps and missing insurer consent can all stop a claim.
• Insurance backing is documentary. If you do not hold the certificate, you may have no policy cover.
• A guarantee is only worth having when the treatment fits the diagnosed cause. A written report that names the cause is the foundation of any later claim.
• Landlords, agents and buyers should file the guarantee, the report and the certificate together, so they can be produced at a sale, a lender’s request or a claim.

What a damp proofing guarantee actually is

A guarantee is the installer’s written promise that the treatment will do its job for a stated period. If damp returns in the treated area because the work failed, the installer returns to put it right. That is the whole of the promise, and it stands or falls on the wording.

Three questions sit behind every guarantee:

1. What exactly is guaranteed? A chemical damp proof course (DPC) injected into a wall, an internal membrane system, a timber treatment and a ventilation upgrade each carry their own terms. A good guarantee names the work, the walls or rooms it covers and the problem it addresses.
2. For how long? Periods vary between contractors and between types of work.
3. Who pays if the contractor cannot? This is where an insurance-backed guarantee matters.

There is no general legal requirement for a contractor to provide an IBG. The National Home Improvement Council says there is no legal requirement to offer one, though it regards doing so as good practice. That makes it a point of difference between contractors, and one worth weighing when you compare quotes. Our guide on how to choose a damp proofing company sets out the other points to compare.

Contractor guarantee or insurance-backed guarantee

The difference is what happens if the company that gave the guarantee no longer exists.

The Property Care Association’s scheme partner, the Consumer Protection Association (CPA), describes its IBG in the same terms: the installer provides the written guarantee, and the insurance covers that guarantee if the installation company ceases trading, subject to the policy terms. It says its cover is available for up to 10 years and is underwritten by an authorised insurer.

The key point is that the insurance protects the guarantee. It does not replace it. A defect has to fall within both the original guarantee and the policy before anything is paid.

How long a guarantee lasts

The professional surveying publication isurv notes that IBGs typically run for 10 years, or the shorter period of the contractor’s guarantee, and that payment depends on the exact policy wording. So two headline numbers can hide very different cover: a long contractor guarantee with a shorter insurance period, or the reverse.

When you read any guarantee, find these in the document itself rather than the brochure:

• the start date and the end date of the guarantee;
• the start date and the end date of any insurance;
• whether the term applies to all the work or only to part of it;
• what the guarantee says happens when the property is sold.

Proofterior’s guarantee is 25 years, insurance-backed, and applies to all treatment work. That length is worth stating next to the work it covers, because damp treatments are expected to last, and a lender, buyer or landlord will want to see a term that matches the life of the repair.

What guarantees normally exclude

The headline term is the part that gets quoted. The exclusions decide whether a genuine defect gets paid. isurv lists the limits that commonly appear in IBGs: no cover for work outside the policy, failure to maintain the work or the property, structural alterations or interference, consequential and indirect losses, policy caps or excesses, and remedial work carried out without the insurer’s prior consent.

In plain terms:

• Maintenance. Blocked gutters, a leaking downpipe or soil piled against a treated wall can cause new damp that has nothing to do with the treatment. Keep the building’s rainwater goods clear and the ground level below the DPC.
• Alterations. Drilling through a membrane, re-plastering with the wrong material or raising an external path over the DPC can interfere with the work. Tell the contractor before you alter a treated area.
• Indirect losses. Damaged carpets, furniture or decoration are usually not the same as a defect in the treatment, so they may not be paid.
• Caps. The NHIC explains that payment is usually limited by reference to the original contract price.
• Prior consent. If you instruct someone else to repair a failure before the insurer agrees, the claim can fail.

A new damp problem from a different source, such as a roof leak or a failed gutter, is a different cause and needs its own diagnosis. That is why the survey comes first: a treatment for rising damp does nothing for a leaking valley. Penetrating damp treatment and condensation and ventilation work address different causes, and each should be recorded against the right one.

Why the diagnosis comes before the guarantee

A guarantee on the wrong treatment is a guarantee of a repair that was never going to work. Damp has several distinct causes: rising damp from the ground, penetrating damp through walls or roofs, condensation from moisture that cannot escape and leaks from pipes or drains. They look alike on a wall and need different remedies.

A written report that names the cause, shows where the readings were taken and sets out the treatment does three jobs:

1. It tells you why the recommended work fits the problem.
2. It sets the scope of the guarantee, because the guarantee covers the work done for the cause named.
3. It gives a later buyer, lender, landlord or insurer a record to rely on.

Proofterior’s process starts with a complimentary property survey and a detailed written report on the root cause, so the treatment is tailored rather than guessed. The case studies show the approach in practice: a black mould and condensation fix in Southampton was solved through ventilation, and a roof leak near Andover was solved at the roof valley. If the guide How to Fix Damp That Keeps Coming Back describes your wall, it is usually because the first treatment targeted the wrong cause.

The paperwork: certificates and who underwrites them

Insurance backing is a document, not a verbal assurance. The CPA says consumers must apply for its IBG and receive an insurance certificate; without it, they are not insured under that scheme. It also says the application should be made within 28 days of satisfactory completion and after paying the member.

So after any damp treatment, make sure the following are in one folder:

• the survey report and the specification of works;
• the signed guarantee, with the start date and the areas covered;
• the insurance certificate, naming the insurer;
• the invoice and proof of payment;
• any maintenance conditions the guarantee sets, for example an annual check.

If a certificate is missing, ask the issuing body for a copy. Official guidance on competent person schemes says that a registered installer issues a compliance certificate for work covered by a scheme, and that if one is missing you should contact the scheme operator to request it. Do this early. A certificate that cannot be found when a buyer’s solicitor asks for it can slow a sale.

After the work, you may also want the property cleaned of building dust before you refit the room. This after builders cleaning checklist covers the dust controls that apply to that clean.

Making a claim

If damp returns in a treated area, act quickly and in this order:

1. Contact the installer first. The guarantee is their promise, and they carry out the remedial work.
2. Do not start repairs yourself. Remedial work done without the insurer’s consent can invalidate a claim.
3. Photograph the area and keep dated notes. Record the date you first noticed the problem and the readings if you have them.
4. Check for a different cause. A new leak, blocked gutter or raised ground level is a separate matter.
5. If the installer has stopped trading, use the insurance. The NHIC says an IBG claim normally involves a claim form and an inspection or report by another contractor to establish the cause and the repair cost. Payment depends on the defect falling within both the guarantee and the policy.

This is the reason to keep the original report. It shows what the cause was judged to be and what was treated, which is the starting point for any later inspection.

Buildings insurance is a different route

A damp proofing guarantee covers the quality of the treatment. Buildings insurance covers insured events such as a burst pipe or storm damage, and it usually does not cover damp that develops gradually. A Financial Ombudsman decision on a damp claim shows how expert evidence on the source of the damp and whether it was gradual can be decisive. A clear written diagnosis helps in either case. Check your own policy wording and speak to your insurer before assuming either route applies.

Landlords, agents and responsibility

For a landlord, the guarantee is part of the property file. Citizens Advice says a landlord should not simply blame a tenant for damp and is responsible for finding the cause, and that an existing DPC failure and many structural or exterior defects are generally the landlord’s repair responsibility. A written diagnosis by a specialist is the evidence that separates a building defect from condensation. Our guides on mould in a rental property and mould remediation for landlords cover the responsibilities in more detail.

For estate agents and sellers, the useful combination is a report, a transferable-looking paper trail and a guarantee that is still in term. A buyer’s surveyor or lender who sees a named cause, a completed treatment and a current insurance-backed guarantee has far less to query than one who sees a patch of fresh paint.

Questions to put to any contractor before you sign

These apply to every quote you compare:

• Is the guarantee insurance-backed, and for how long?
• Does it cover all the work in the quote or only part?
• Is the work done by the company’s own employees or by subcontractors? In-house teams mean one company is accountable for the whole job, which is how Proofterior works.
• Will the quote be preceded by a survey and a written report naming the cause?
• What maintenance conditions apply, and what would void the guarantee?
• Which trade body does the contractor belong to? Proofterior’s work is PCA aligned and accredited.

A contractor who can answer each of these in writing has usually thought about the job as well as the sale.

Where Proofterior fits

Proofterior treats damp, mould and timber problems in homes across Dorset, Hampshire and Wiltshire, from damp proofing to timber treatment, mould removal and air quality and ventilation and energy efficiency upgrades. Every job follows the same sequence: a complimentary survey, a detailed written report on the root cause, treatment by in-house specialists and a 25-year insurance-backed guarantee on the treatment work.

Homeowners, landlords, agents and businesses can book the survey through the Complimentary Property Survey page.

The full list of services is on the services page.

Our view on guarantees

A guarantee should be the end of a process, not a selling line at the start of one. The sequence that works is a survey, a report that names the cause, a treatment matched to that cause and a guarantee on the work done.

We carry out all diagnostic and remedial work with our own in-house specialists, not subcontractors. One team surveys, writes the report and does the work, so the person who diagnosed the damp is accountable for the result. That is why we can put a 25-year insurance-backed guarantee on all our treatment work.

Our advice to any owner or landlord is to keep the report, the guarantee and the insurance certificate together from the day the work finishes. Those three documents are what a buyer, a lender or a tenant’s adviser will ask for years later.

Dylan

FAQ

Do you need a certificate for damp proofing?

Yes, if you want to rely on insurance backing. The CPA says a consumer must apply for and receive an insurance certificate, and without it they are not insured under its scheme. Keep it with the guarantee and the survey report.

Can you claim for damp on buildings insurance?

Sometimes, but it depends on the cause. Buildings policies generally respond to insured events, and evidence about the source of the damp and whether it was gradual can decide a claim. Read your policy wording and speak to your insurer.

Can my landlord blame me for damp?

Not simply on the basis that damp is visible. Citizens Advice says the landlord is responsible for finding the cause, and an existing DPC failure or a structural or exterior defect is generally the landlord’s repair responsibility. A written diagnosis settles the question.

How long does an insurance-backed guarantee last?

It depends on the contract and the policy. isurv says IBGs typically last 10 years or the shorter period of the contractor’s guarantee. Proofterior’s insurance-backed guarantee on treatment work is 25 years.

Sources

• Home Improvement Insurance & Guarantees, The CPA
• Guide to Insurance Backed Guarantees, The NHIC
• Take cover: Insurance-backed guarantees, pros and cons, isurv
• What are Competent Person Schemes?, Building Control Solutions
• Damp or mould in your rented home, Citizens Advice
• Financial Ombudsman Service decision DRN-3491819
• After builders cleaning checklist

Recommended

• How to Choose a Damp Proofing Company
• Basement Waterproofing Methods: 3 Types, UK Costs and Pump Risks
• What Is a Damp Proof Course (DPC)?
• Damp Proofing & French Drain in Salisbury