How to Choose a Damp Contractor: A Practical Checklist

Choose the damp contractor who identifies the cause of the moisture before quoting for any treatment, puts the findings in a written report, uses their own trained staff and backs the work with an insured guarantee. That is how we work at Proofterior: a complimentary survey, a detailed written report, in-house specialists and a 25-year insurance-backed guarantee on treatment work, across Dorset, Hampshire and Wiltshire.

This guide is for homeowners, landlords, agents and businesses who need damp or mould dealt with properly and want to know what a good contractor looks like before they sign.

Key Takeaways

• Diagnosis comes first. Damp can come from several sources, and treating the wrong one wastes money and can make things worse.
• A good survey ends in a written report that names the cause, the evidence and a proportionate repair, not just a price.
• Check accreditation (such as PCA membership), who actually does the work, and what the guarantee covers and who insures it.
• Compare quotes on scope and cause addressed, not on the headline figure alone.
• Landlords have specific duties, and social landlords in England now work to fixed deadlines under Awaab’s Law.

Why the choice of contractor matters

Damp is a symptom. The visible patch, the peeling paint or the black mould on a bedroom wall is the result of water getting in, or moisture building up, somewhere else. Historic England’s guidance lists the possible sources: occupants’ daily activity, building defects, faulty services, leaking utilities or drains, groundwater, floods and fires. It also states that an incorrect diagnosis can waste money and make remedial work worse.

That is why the first question to ask any contractor is not “how much?” but “what is causing it, and how do you know?” The RICS consumer guide to damp and mould makes the same point: the first step is to identify and remedy the moisture source, because treating mould alone addresses the symptom and not the underlying cause.

A few common situations show how much the diagnosis matters:

• A damp patch low on a ground-floor wall may be rising damp, but it may equally be a bridged damp-proof course, high external ground levels, a leaking drain or a failed render.
• Black mould in the corners of a bedroom is often condensation from poor ventilation. A wall treatment will not fix it. Ventilation will. Our guide to telling damp and condensation apart explains the signs.
• Brown staining on a ceiling below a chimney breast or roof slope points to water ingress from above, a roofing or chimney repair rather than a damp proofing job.

A contractor who sells one product for every wall is guessing. One who looks at the whole building is diagnosing.

What a proper damp survey includes

A survey is the point where you can judge a contractor most easily. It should be a structured inspection, not a quick walk-round with a moisture meter followed by a quote.

The Property Care Association’s Code of Practice for the control of dampness in buildings (January 2023) sets out what information should be gathered before an inspection: building size, age, structural stability, hazards, services, access, occupation, intended use, current conditions and previous repairs. It also says inspections must be carried out by adequately trained staff who can produce clear, unambiguous reports and appropriate repair strategies, with knowledge of traditional construction.

In practice, that means the surveyor should:

1. Ask about the history. When did you notice it? Has it been treated before? Has the property been altered, re-rendered or re-plumbed? Is it lived in full-time?
2. Inspect inside and out. Gutters, downpipes, ground levels, pointing, render, airbricks, drains, roof and chimney all feed into the diagnosis.
3. Take readings and interpret them. A moisture meter reading on its own proves little. It needs to be read alongside the building’s construction and the surrounding evidence.
4. Consider ventilation and use. Cooking, drying washing, bathroom use and heating patterns all affect condensation and mould.
5. Explain the cause in plain language at the time, or in the report that follows.

If you want to see what this looks like before booking, our pages on what a damp survey is and what happens in a complimentary damp survey walk through the visit step by step.

What the written report should tell you

A verbal opinion is not enough for a decision costing thousands of pounds, and it is not much use to a mortgage lender, a buyer’s solicitor or a letting agent. The report is the document you keep, share and rely on.

A useful report states:

• the property, the date and the areas inspected;
• what was found, with the readings and observations that support it;
• the cause or causes identified, ranked by how much they contribute;
• the recommended remedial work, room by room or elevation by elevation;
• anything outside the contractor’s scope, such as a plumbing leak that needs a separate repair;
• the guarantee that applies to the treatment.

RICS says a good report should recommend works that are proportionate and suited to the property. That is a good test for any quote: does the scope match the cause found, or is it a standard package applied to every job? Proportionate work respects the nature of the building. A solid-wall Victorian terrace in Southampton, a thatched cottage near Fordingbridge and a 1990s cavity-wall house in Poole do not need the same treatment.

Our survey results come as a detailed written report, so the cause, the evidence and the recommended work are on paper before you decide anything.

Accreditation: what to check and what it tells you

Damp proofing is not a licensed trade in the UK, so anyone can use the name. Membership of a trade body is the quickest way to see who works to a recognised standard.

Property Care Association (PCA). The PCA is the main trade body for damp proofing, timber treatment and structural waterproofing. According to the PCA’s page for homeowners, its members can offer insurance-backed guarantees, some of which are only available through a PCA member. The same page says contractor members are licensed under the TrustMark scheme and that a deposit protection scheme applies to damp proofing, timber preservation, structural waterproofing and structural repair works.

Surveyor qualifications. The PCA’s 2025 contractor application form says practising surveyors in the timber-and-damp membership category must hold CSTDB or CSRT, and structural-waterproofing surveyors must hold CSSW. Ask which qualification the person visiting your property holds.

When you check, do these four things:

• Ask for the company’s membership details and confirm them on the trade body’s own member search.
• Ask for the surveyor’s qualification, not only the company’s badge.
• Ask whether the person who surveys will also be responsible for the work, or whether it is passed on.
• Ask for the insurer’s name and the guarantee wording in writing.

At Proofterior, our work follows PCA industry standards and we are PCA aligned and accredited.

In-house team or subcontractors

Many firms sell the job and then subcontract it. The person who diagnosed the problem is then not the person holding the drill, and no one on site may know why a particular method was chosen.

Ask directly: “Will your own employees carry out the work?” At Proofterior, all diagnostic and remedial work is done by our in-house specialists, not subcontractors. The surveyor’s findings and the repair that follows stay connected, and the same company is accountable for both.

Guarantees: what to read before you sign

A guarantee is only as good as the company and the insurer standing behind it. A long period on a leaflet means little if the firm has closed by year five.

Read these points in the guarantee document itself:

• Duration and scope. Which work does it cover: the whole treatment or one element?
• Insurance backing. Is the guarantee insured, so that a claim does not depend on the contractor still trading?
• Transferability. Can it pass to a buyer if you sell? This matters for landlords and agents.
• Conditions. What maintenance is expected of you, such as keeping gutters clear or ventilation running?

Our treatment work carries a 25-year insurance-backed guarantee. A guarantee of that kind is also useful at sale: buyers and their solicitors tend to ask for evidence of past damp work, and a written report plus a guarantee gives them paperwork rather than a story.

Comparing quotes properly

Two quotes for “damp proofing” can describe very different jobs. Line them up by scope before you look at price.

A cheaper quote that skips the cause often costs more in the end, because the problem returns and the work is repeated. If you have already had work done and the damp has come back, our page on how to fix damp that keeps coming back explains why that happens.

Condensation and mould

If the survey points to condensation, the fix is usually about moving moist air out: extractor fans, positive input ventilation or improved airflow, sometimes with insulation to warm cold surfaces. Mould is then cleaned and the surface treated. One of our Southampton jobs, black mould and condensation solved with a PIV unit and extractor fan, shows how the cause drives the repair. Our condensation and moisture control and mould removal and air quality services cover this work.

Rising and penetrating damp

For rising damp, treatments include chemical damp-proof course injection or internal membrane systems, chosen to suit the wall. For penetrating damp, the repair often starts outside, with the roof, chimney, masonry or drainage. See our examples: an internal dry system and French drain in Salisbury and an internal membrane system in Bournemouth.

Timber

Damp and timber decay go together. Wet rot, dry rot and woodworm all need moisture, so controlling the moisture source is the first step of any timber treatment. A general read on woodworm prevention and moisture control shows why. Where decay is already present, our timber treatment service covers the survey, treatment and restoration.

Special considerations for landlords, agents and businesses

Private landlords. Damp that makes a home unsafe is a landlord’s responsibility to investigate and repair. A survey and report give you a dated record of the cause and the action taken. Our guide to mould in a rental property sets out who is responsible and what to do.

Social landlords in England. Awaab’s Law sets timeframes for the social rented sector. Under the guidance published on 16 July 2026, emergency hazards must be investigated and made safe within 24 hours. For significant damp and mould hazards, the investigation must take place within 10 working days, with written findings within 3 working days after that, safety work within 5 working days and preventative work starting within 5 working days. The guidance says this phase does not apply to owner-occupied homes. A contractor who can survey quickly and report in writing fits those deadlines.

Estate agents and sellers. A buyer’s surveyor who flags damp will often ask for a specialist report. A written survey, with the cause identified and a proportionate repair priced, usually keeps a sale moving better than an open question.

Businesses. For commercial premises, structural and water damage, roofing and moisture can affect use as well as the fabric. The same rules apply: cause first, report in writing, own staff, insured guarantee.

Questions to ask before you book

1. What do you think the cause is, and what would change your mind after inspection?
2. Will I receive a written report, and what does it include?
3. Which trade body are you a member of, and what qualification does the surveyor hold?
4. Will your own employees do the work?
5. Is the guarantee insured, how long does it run and what does it cover?
6. What related repairs are outside this quote?
7. What do I need to maintain afterwards?

A contractor who answers these clearly and in writing is a good sign. One who answers with a price and a start date is not.

Our complimentary survey

We offer a complimentary property survey across Dorset, Hampshire and Wiltshire, including Bournemouth, Christchurch and Poole, Southampton, Winchester, Dorchester, Salisbury and Fordingbridge. It leads to a detailed written report, and any treatment we carry out is covered by a 25-year insurance-backed guarantee. You can see the full range, from damp proofing to ventilation, timber, roofing and energy efficiency, on our services page.

For a wider look at our approach, see how to choose a damp proofing company and our main damp proofing page.

Our perspective

Most failed damp jobs we are asked to look at share one thing: the treatment was chosen before the cause was found. A wall gets injected when the real problem is a blocked gutter. A bedroom gets a mould wash when the real problem is no extraction.

That is why our work starts with a survey and a written report. The report is the contract between what is wrong and what gets done, and it is the first thing we would ask any contractor for.

We also keep the work in-house. The specialist who diagnoses the problem is part of the team that fixes it, and the 25-year insurance-backed guarantee on treatment work stays with one accountable company.

Choose the contractor whose paperwork you can read, whose people you can name and whose guarantee you can hold in your hand.

Dylan

FAQ

How much does a professional damp survey cost?

Prices vary by firm, property size and location, so there is no single figure. Some contractors charge for surveys and others, including us, offer a complimentary survey that leads to a written report. Ask what the report includes and whether the fee is credited against any work.

Who deals with damp problems in a property?

A damp and timber specialist contractor surveys the property, identifies the cause and carries out the remedial work. Where the cause is a leaking pipe, drain or roof, the repair may involve plumbing or roofing work as well. We carry out damp proofing, ventilation, timber and roofing repairs under one survey and report.

Is it illegal to sell a property with damp?

No, but sellers should answer buyers’ questions about known damp honestly and in full. A written survey and a record of any treatment help the sale proceed with fewer surprises. Your solicitor can advise on the disclosure forms for your own sale.

Does a PCA badge guarantee a good job?

It shows the contractor works within a recognised trade body’s standards, with surveyors holding the required qualifications. You still need to check the diagnosis in the report, the scope of work and the guarantee wording. We combine PCA-aligned standards with in-house specialists and a written report on every survey.

Sources

• RICS: Damp and mould consumer guide
• Historic England: Investigation of moisture and its effects on traditional buildings
• PCA Code of Practice: Control of Dampness in Buildings, January 2023
• PCA: Why choose a PCA member
• PCA: Full contractor application form 2025
• GOV.UK: Awaab’s Law guidance for social landlords, timeframes for repairs
• Woodworm prevention and moisture control

Recommended

• How to Choose a Damp Proofing Company
• Rising Damp vs Condensation Guide
• What Is a Damp Survey?