What is a damp proof guarantee & how long does it last?

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Most professional trades will offer some kind of guarantee when they carry out work on your property. The same is true for damp proofing companies. They will usually offer some type of damp proof guarantee, and this will cover the customer for any future issues relating to the work carried out.

For example, if a company installs a new DPC (damp proof course) and a couple of years later rising damp returns, the company will need to come out and rectify the problem.

This is obviously an advantage to doing the work yourself, for 2 reasons:

  1. The original job will be done professionally. Due to this you would expect the work to be of a high standard and it shouldn’t have any issues.

  2. If there are issues, you don’t have to repair it yourself, and you don’t have to pay more money. The guarantee will cover the cost.

As you can see these are major advantages and it can remove the stress of repeat dampness. Most damp proofing companies will offer guarantees that last decades. This shows they are confident in the original work not having any issues.

what is a damp guarantee

How long does a damp proof guarantee last?

The duration of a damp proof guarantee can vary, but it will usually range between 10 – 30 years. This will depend on who you hire. However, the industry standard is 20 years, and, in our experience, this is offered by the majority of established, trusted damp proofing companies.

If you are quoted for work and there is only a 10-year guarantee, it might be worth shopping around a little. Also, if a company is offering a 30-year guarantee, whilst this is great, you should check how established the company is. For example, a one-man local business that’s been trading for a short time may offer 30 years, but is this company guaranteed to be around in 3 decades.

These are just things you need to consider. Obviously, a longer policy will give you more protection, but a guarantee with no company backing it is essentially worthless.

Due to this, if you are carrying out large scale damp proofing work, it is worth shopping around to find the best possible quotes and guarantees, from the best possible companies.

Comparing quotes and damp-proof guarantees

By far the easiest way to compare is using online comparison sites. Doing this will allow you to receive multiple quotes from a variety of companies.

Using these types of sites has several advantages. These include:

  • You can find a large number of accredited damp proofing companies in one place.
  • The comparison site will screen companies who are advertising on their website. This means, they are who they say they are, and you have less chance of hiring cowboys.
  • Previous customers rate and review the companies. As a result, you can read reviews and ensure you are hiring a good company, with good previous feedback.
  • All qualifications and guarantees will be available to view on the company’s profile page.
  • Finally, these sites are competitive marketplaces. Companies know they are competing against each other, so you are far more likely to get competitive quotes. We have seen discounts of 30% or more.

To see our favourite damp proof comparison site, Click Here

What if your damp guarantee company goes bust?

As we have already mentioned previously, a guarantee with no company to back it up is not worth the paper it is printed on, and this can happen. Many companies go out of business every year. Figures suggest that 20% fail in their first year. This jumps to 60% in the first 3 years and only 1 in 3 will last a full decade (10 years).

Considering these statistics, it is no surprise that many damp companies do go out of business and are unable to honour their damp proof guarantees.

So, what can you do?

Really the best thing you can do, is to make sure you hire an established firm. This would be a company that has already been in business for many years (10+ years preferably).

If you do find yourself in the situation, where a company has gone out of business, and can’t honour your damp guarantee. Don’t worry, not all hope is lost.

If they were a reputable company, their guarantee should have been backed by some kind of insurance company, who will honour the guarantee

Failing that, there are companies who can offer new guarantees for existing work. Generally, you will need to pay a small one-time fee of £300 – £400. However, after this, the work will be covered again for somewhere between 20-30 years.

With that said, this is providing there is no current damp issue for the work being guaranteed.

Unfortunately, if you don’t have an insurance backed guarantee and your damp proofing has failed, you will be out of luck and the burden of payment will lay on your shoulders.


As with any guarantee, a damp proof guarantee is a great thing to have. It ensures that your work is protected from future defects that allow damp to re-enter your property.

To ensure you get good cover that will be reliable way into the future make sure you hire established companies who offer insurance backed guarantees for the work they carry out.