Timber treatment guarantees, and what they are actually worth

A guarantee is a promise about the future made by somebody who wants your money now, so the only sensible way to read one is to ask who is making the promise, what exactly it covers, and what happens to it if the person who made it disappears. In timber treatment, all three of those questions have real answers, and most homeowners never get asked to think about them.

We will start with the honest position. This site is not the contractor. It puts enquiries in front of an approved local team, and the guarantee on any work comes from the firm that does it, on their paper, with their terms.to be confirmedto be confirmedNothing on this page should be read as a claim about a specific arrangement until those are filled in with something real.

What we can do in the meantime is more useful anyway: tell you how these documents work, so that whoever you end up hiring gets asked the right questions.

What a timber treatment guarantee actually is

It is a written undertaking that if the specific problem that was treated reappears in the specific area that was treated, within a stated period, the firm will return and deal with it at no further cost. That is the whole of it. Three words in that sentence do all the work: specific problem, specific area, and the firm.

So a guarantee is only as good as the drawing or schedule attached to it. If the document says the works were guaranteed but never says which joists, which wall, which elevation or which floor void, then in any dispute you are arguing about what was meant rather than pointing at what was written. A guarantee that names the treated area, the timbers replaced, the product used and the specification it was applied to is a far stronger document than a longer one that names none of those.

A company guarantee and an insurance backed guarantee are different things

This is the distinction worth understanding before anything else.

A company guarantee is the firm's own promise. If the firm is still trading in eight years, still solvent, still willing to come back and still recognises the job, it is worth something. If the firm has closed, it is worth nothing at all, and you have no claim against anybody, because the company that made the promise no longer exists. Timber treatment is a trade with a lot of small firms, and firms in it stop trading, get sold and get restarted under new names regularly enough that this is not a theoretical risk.

An insurance backed guarantee, often sold as guarantee protection insurance, is a separate policy bought at the time of the work and underwritten by an insurer. It sits behind the company guarantee and responds if the company has ceased trading. It usually costs a small percentage of the job, it is normally optional, and it is the only version of a guarantee that survives the firm folding. If you take one, keep the policy document itself, not just the guarantee certificate, because the policy is the thing that pays.

Ask which of the two you are being offered, in those words. A firm that answers clearly is telling you something about how it operates. A firm that treats the question as an insult is telling you something too.

BS 8417, and why a quote that mentions it is worth more

BS 8417 is the British Standard covering the preservation of wood. It sets out the idea of a desired service life for treated timber, and it links the treatment specification to where the timber will sit and what it will be exposed to. Timber in a ventilated internal floor is a different case from timber built into a solid external wall, and the standard is what turns that difference into a specification rather than an opinion.

You do not need to read it. You need to notice whether a quote refers to it. A quote that specifies treatment against a named standard has committed to something measurable, and its guarantee is attached to that commitment. A quote that promises to treat the affected timbers has committed to nothing in particular, and its guarantee is attached to that.to be confirmed

What a guarantee will not cover

Most disagreements in this trade are not about firms refusing to honour guarantees. They are about homeowners discovering what was never inside the guarantee to begin with. In general terms, expect all of the following to sit outside it.

• New water from a different source. If the original leak is fixed and a different defect wets the same timber later, that is a new job.
• Anything outside the treated area. Rot appearing two rooms away is a separate problem, even if it is the same fungus and the same building.
• Failure to maintain the building. Blocked gutters, an unrepaired roof, a failed downpipe or ground levels bridging a wall will normally void a claim on the timber they wet.
• Consequential damage. The guarantee covers the timber and the treatment, not the flooring, decoration, kitchen units or carpets that have to come out to reach it.
• Work done by somebody else. Another trade cutting into treated timber, or a later alteration, usually ends cover on that section.
• Condensation and general dampness that was never part of the reported defect.

The questions to ask before you accept any guarantee

These work on us and on anybody else. Ask them out loud, and write the answers down.

1. Is this your own guarantee, or is it insurance backed?If it is insurance backed, who underwrites it, and can I see the policy wording rather than the certificate?
2. Exactly what area does it cover? Point at it on the plan or the schedule. If there is no plan or schedule, ask for one before the work starts, not after.
3. What specification was the treatment applied to? Which product, at what rate, and against which standard.
4. Does it transfer if I sell? Once, or repeatedly, and is there a fee or an inspection.
5. What voids it? Ask for the exclusions in writing before you sign, and read the maintenance conditions in particular.
6. Who do I contact, and how, in five years? A name of a firm, a company number you can look up, and a method of claiming.
7. Which trade body do you belong to, if any, and can I check it?Membership of the relevant body can be verified on that body's own register in a couple of minutes, and the check is worth more than a logo on a van.to be confirmed

Why this matters more in Scotland than the brochures allow

Guarantees assume that once the source of water is fixed, it stays fixed. That assumption is weaker in Scottish tenement stock than almost anywhere else in the housing market, and it is worth understanding why before you rely on one.

Roofs, gutters, downpipes, hoppers and the close itself are commonly shared, and under tenement law they belong to everybody, which in practice often means nobody attends to them until something visible fails. A cracked hopper or a blocked shared gutter can run down the same patch of sandstone for years. Joist ends are built straight into that solid wall with no cavity and no damp proof course between the timber and the weather. So the new timber that goes in as part of your repair can be sitting in exactly the same conditions as the timber it replaced, unless the shared defect above it has been sorted.

That has two consequences. The first is that the guarantee on your flat is partly hostage to a common repair you do not control on your own, which is a good argument for getting the surveyor's findings on the shared defect in writing, because that document is what you take to the other owners or the factor. The second is that if the source of water was never fixed, no guarantee length is going to save you. It will simply be excluded as a new ingress, and the firm will be right to exclude it.

So the order of priorities is the opposite of how these are usually sold. The survey that finds and names the water is the thing protecting you. The guarantee is what covers the smaller risk that the treatment itself did not work. A firm leading with a very long guarantee and showing little interest in where the water came from has those two the wrong way round.

Where we stand

The work is carried out by the approved local team covering your side of the Central Belt, and their guarantee terms are theirs to state, not ours to imply.to be confirmedUntil that is in place, what this page offers is the list above. If you use it on us and we cannot answer clearly, that is a real answer and you should treat it as one.

Book a timber survey and you will get the findings in writing whether or not any work follows, which is the part you can actually use.