waterproof guarantee basement construction build manage
  waterproof guarantee basement construction build manage
 

A guarantee means different things to different people.


  1.   Occupier: No leaks. Simple.

  2.   Developer: No call outs, no repair costs, property easily sold on.

  3.   Latent Defect Warranty provider. No claims.


We understand how these 3 customer requirements are completely distinct and different from each other.


  1.   The Occupier wants good workmanship.

  2.   The Developer wants the correct paperwork in place. Latent Defects Warranty.

  3.   The Latent Defect Warranty provider wants to be risk free. He wants his own protection.



Complete peace of mind for all requires all 3. Good workmanship throughout, latent defects insurance, insurance backed warranty from a waterproofing supplier.

You cannot have just one or two.

You cannot just have two of them, for instance 2, the latent defects insurance and, 3, insurance backed internal drainage because neither guarantees that the pump will always work, year after year, if it is pumping nearly all the time. And if the pump fails in a leaky basement then the basement will flood. But you cannot claim, you just have to get a new pump.

You cannot just have 1 and 3 because without latent defects insurance you cannot sell a new property.

Or just 1 and 2 either, because the latent defects insurer will fear he faces a risk if there isn't internal drainage.


  1. We leave you a basement that does not visibly leak, at all, probably completely waterproof.

  2. We will return and stop any visible water coming through our work for 12 years.

  3. We will fit a sump for a pump to enable a fitter who gives you a warranty to install his equipment easily.

You have to have internal drainage (unless you don't borrow and won't sell for 10 years) and if you want the pump to never fail for 10 years or more, either because of a break down or a power cut, you need the basement built never to leak.



That is what we do. Build basements with no visible leak through our work.





None of the basements we built in the last 7 years has any leak.

Most were for clients to live in themselves so many don't have internal drainage. They are dry from our workmanship alone.

We built this basement during 2015 and the clients moved in November 2016.

self build basement house
  The basement has no insulation, no heating and no internal drainage. So far it has been a constant 10°C. And it is dry.

self build basement house




If you ask 101 people for advice about waterproofing a basement you will get 101 different answers.

The reason for that is usually to do with poor workmanship.

The best advice will be to BS 8102: Code of practice for the protection of below ground structures against water from the ground.

BS 8102 states two defences and:

"the water resistance of the structure should be improved prior to the installation of the Type C protection".

The first defence needs to work so that the second could never be overwhelmed.


We were once asked to see a basement in Hammersmith that leaked everywhere.

Over 8 years the various pumps failed many times and the basement kept flooding.

Most basement labour, who see on the drawings that internal drainage will hide and cope with all the leaks, don't care.

When we visited, the screed and floor drainage were still in place, still hiding the worst leaks.

This photo was taken 8 years after the basement was complete and the internal drainage taken off the wall. It leaked all that time.

In our experience, many main contractors employ the cheapest to build the basement for them; and they charge the client double in case they have to rebuild it properly.
leaking basement


The approach we take is
  1. We do our best so that your basement will never leak, not even a drop, from the concreting alone.

  2. You have internal drainage as well for peace of mind, if you wish, or more often because your lender or your future buyer want it.
If you have internal drainage, you need to liaise with the supplier before you build your basement, even though they cannot install anything until after your roof is on, your windows are in and your basement cleaned of everything that washed down into it while the house above was built. This is because you might need to put their membrane under internal walls before they are built.

Most of our competitors give you 2 and 3. We believe we are unique giving you 1, a basement that will never leak.


Hopefully you can see the difference.

Our 12 year guarantee

Our 12 year guarantee is just a personal guarantee against visible leaks. If you need a mortgage or you plan to sell within 10 years you probably need the insurance backed warranty available with internal drainage as well.



If you need to borrow and getting a mortgage for a basement is proving difficult,

Clients in the past have
  1. Funded the basement construction from their savings and only drawn down funds after the basement structure is complete, satisfying their lender that his money is tied up only above ground in the part of the new dwelling that has a full warranty.

  2. Our founder once paid QANW almost £8,000 for a policy later assigned to NHBC, so that although NHBC insured the basement without internal drainage, they were fully insured themselves.

  3. When you wish to sell, if it is within 10 years, buy a policy for the remaining time only. Warranties are only for latent defects, the completely unexpected. So if after 5 years you have no problems you will easily get insurance for the next five years.



We have a number of other pages with information.


waterproof basement construction   You Must Have a Soil Report Before Design Starts   Please Ask Your Architect To Read This Page   Please Ask Your Structural Engineer To Read This Page   construction contract

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