Damp Proofing and Waterproofing Contractors Insurance
Damp proofing sits closer to professional services than most people in the trade realise. You are diagnosing a problem, specifying a remedy, and then guaranteeing that the remedy works, often for decades. That is three separate liabilities, and only one of them, the physical work, is what a standard contractors policy is built around.
The one that produces claims is the guarantee. Long term guarantees are the industry's main selling point and its main exposure, because insurance policies almost universally exclude efficacy, meaning they will not pay because a treatment failed to achieve the promised result. Insurance backed guarantees exist precisely because ordinary liability cover does not do this job.
Misdiagnosis is the other one. Condensation misidentified as rising damp leads to an injected course that was never going to work, and the claim is not about workmanship but about the advice. That is professional indemnity territory, and a great many damp proofing contractors do not carry it.
We arrange cover for damp proofing, basement waterproofing and timber treatment contractors, and the two questions worth settling early are how your guarantees are backed and whether you carry cover for the advice as well as the work.
What actually goes wrong
The exposures that produce claims in this trade, rather than a generic list.
Guarantees and efficacy
A twenty or thirty year guarantee is a contractual promise that the work will keep performing. Liability policies exclude efficacy, so if the treatment fails and the customer claims under the guarantee, the policy does not respond. That obligation sits on the business, which is why insurance backed guarantees are arranged separately.
Misdiagnosis
The most common professional claim in the trade. Condensation, penetrating damp, plumbing leaks and rising damp present similarly and require entirely different remedies. Specifying and carrying out the wrong one produces a claim for the cost of the unnecessary work plus the cost of the correct remedy plus the continuing damage.
Basement and structural waterproofing failure
A failed basement waterproofing system floods a finished habitable space, and the damage runs through floors, walls, contents and often electrics. Basement conversions carry the highest values in this trade and the least tolerance for failure.
Chemical treatments
Injected damp proof courses and timber treatments involve chemicals applied inside occupied buildings. Exposure to occupants, damage to finishes and staining are all live exposures, and treatment in confined roof voids and cellars adds a health and safety dimension.
Structural intervention
Hacking off plaster, removing floors, and excavating internally to install drainage or a membrane system all disturb the fabric of an occupied building. Where a wall turns out to be doing more structural work than assumed, the intervention becomes a much larger problem.
The cover we arrange
Policies are put together around how you work. Employers liability is included as standard wherever you employ anyone.
Public liability
Third party injury and property damage arising from the work. Most damp proofing takes place in occupied homes and buildings, so damage to decoration, flooring and contents is the frequent claim.
- Damage to finishes, flooring and contents
- Injury to occupants and visitors
- Legal defence costs
- Limits typically £2m, £5m or £10m
Employers liability
Legally required and included as standard at £10m. Work in cellars, roof voids and confined spaces, with chemicals, is the exposure underwriters focus on.
- Legally required, £10m as standard
- Confined space and chemical exposure
- Labour only subcontractors
- Occupational illness and long tail claims
Professional indemnity
The cover that matches this trade's actual risk. Responds to claims arising from surveys, diagnosis and specification, which is where the expensive claims come from. Written on a claims made basis, so it must be maintained continuously and after you stop trading.
- Damp surveys and diagnosis
- Specification of remedial works
- Reports relied on by purchasers and lenders
- Claims made basis, run off available
Contract works
Covers the works in progress: membranes, tanking, drainage and replastering before handover. On basement work the value and the exposure to water during construction are both significant.
- Waterproofing works in progress
- Materials and membranes on site
- Basement and tanking systems
- Water damage during the works
Tools and equipment
Injection equipment, pumps, dehumidifiers, moisture meters and hand tools. Dehumidifiers and drying equipment are frequently left in customers' properties for extended periods, which is worth confirming is covered.
- Injection and spraying equipment
- Moisture meters and survey instruments
- Drying equipment left at customer premises
- Vehicle conditions apply overnight
What an underwriter will ask
Having these to hand shortens the process considerably, and usually improves the terms.
- Turnover split between damp proofing, basement waterproofing, timber treatment and replastering
- Whether you carry out surveys and produce written reports
- Whether reports are relied on by purchasers, lenders or solicitors
- The guarantees you offer, their length, and whether they are insurance backed
- Whether you undertake structural waterproofing to habitable basements
- Chemicals used and application methods
- Whether any structural alteration or excavation is involved
- Trade body membership and technician qualifications
- Five years of claims, including guarantee claims settled directly
What moves the premium
Where the price actually comes from, and which parts of it you can change.
Whether you survey and report
A contractor who only installs to somebody else's specification carries far less professional exposure than one producing surveys that purchasers and lenders rely on. That distinction drives the professional indemnity element entirely.
Basement and structural waterproofing
Habitable basement waterproofing carries the highest values and the least tolerance for failure in this trade, and rates well above ordinary damp proofing and timber treatment.
Guarantee length and backing
Long guarantees backed by a recognised insurance backed guarantee scheme present better than long guarantees backed by nothing but the company, because the latter concentrates the obligation on a business that may not outlast it.
Qualifications and membership
Recognised technician qualifications and trade body membership carry real weight in a trade where the main risk is the quality of the diagnosis.
Claims and complaint history
Guarantee claims settled directly, without an insurer involved, still matter and should be disclosed. A pattern of them indicates a diagnostic problem rather than bad luck.
Conditions and exclusions that catch this trade out
Terms vary between insurers, so treat these as the questions to ask rather than a description of any one policy.
Efficacy and guarantee failure
The central exclusion in this trade. Policies do not pay because a treatment failed to work. If a customer claims under your twenty year guarantee, that obligation is yours and not your insurer's, which is exactly why insurance backed guarantee schemes exist as a separate product.
The cost of redoing your own work
Removing a failed system and installing a correct one is a rectification cost. What is insured is the damage caused to other property, such as flooring and decoration ruined by continuing water ingress.
Advice, under a liability policy
Public liability responds to injury and damage, not to the consequences of a diagnosis being wrong. Since misdiagnosis is the most common serious claim in this trade, a contractor with only public liability is uninsured for the thing most likely to happen.
Pre existing damp and condition
You are not insuring the state of the building you were called to. The distinction between damage caused by your work and damage that was already progressing is what condition surveys and dated photographs at the start of a job are for.
Gradual damage
Liability policies generally respond to sudden and accidental damage. Damage that develops gradually over months, which is the natural pattern of a failed waterproofing system, can fall outside cover, and this is worth understanding before relying on the policy for it.
Common questions
Does my insurance cover the guarantees I give customers?
No, and this is the most important thing to understand in this trade. Liability policies exclude efficacy, which means they do not pay because a treatment failed to achieve the result you promised. A twenty or thirty year guarantee is a contractual obligation of your business, and if the business cannot meet it, the customer has nothing. Insurance backed guarantee schemes exist specifically to fill this gap by providing a separate policy that responds if the contractor is no longer able to.
Do damp proofing contractors need professional indemnity insurance?
If you diagnose problems and specify remedies, which is most of the trade, then yes. The most common serious claim in damp proofing is misdiagnosis: condensation treated as rising damp, or a plumbing leak treated as penetrating damp. The customer's loss is the cost of the wrong work, the cost of the right work and the damage that continued in the meantime. Public liability does not respond to any of that, because none of it is damage your work caused. Professional indemnity does.
Am I covered if a basement I waterproofed floods?
It depends what is being claimed. Removing and replacing the failed waterproofing system is a rectification cost and is not insured. Damage the flooding caused to flooring, plaster, contents and electrics may be a public liability claim, though gradual damage over months can fall outside cover where the policy responds only to sudden and accidental damage. If the system failed because the specification was wrong rather than the installation, it becomes a professional indemnity matter.
What is the difference between public liability and professional indemnity for this trade?
Public liability covers what your hands did: injury to people and damage to property caused by carrying out the work. Professional indemnity covers what your judgement did: a survey that reached the wrong conclusion, a specification that was inappropriate, a report a buyer relied on. In damp proofing the second is where the larger and more frequent claims sit, because customers are buying an assessment as much as an installation. Carrying only public liability leaves the main exposure uninsured.
Do I need cover for drying equipment left in a customer's house?
It is worth checking, because it is easily missed. Dehumidifiers and drying equipment are often left running in a property for days or weeks, away from your premises and outside your control. Standard tools cover may be limited to equipment on site during working hours or in a locked vehicle. Where you routinely leave equipment out, tell your broker so the cover reflects it rather than discovering the limitation after a unit disappears.
How long should I keep professional indemnity after retiring?
For as long as claims could realistically be brought, which in this trade is a long time because guarantees run for decades and defects surface slowly. Professional indemnity is claims made, so a policy in force today is what responds to a claim about a survey you did years ago. Once you stop trading there is no renewing policy, so run off cover continues that protection. Six years is a common minimum, matching the limitation period for simple contracts, and longer is often sensible given how long damp proofing guarantees run.
Talk to somebody who knows the trade
Tell us what you actually do and we will come back to you with cover options built around it.