A self build house project diary
by Oliver Cannell
Monday 24th February 2014
(published/edited Tuesday 25th February 2014)

Nobody wanting to ‘tank’ responsibility

For the last 2-3 weeks, getting the warranty sorted has been one of the main issues, as nobody seems to be willing to take responsibility for giving a guarantee for the tanking.

This is complicated. Very complicated. And way more complicated than it needs to be.

So, everyone's heard of warranties and guarantees. They're everywhere - usually when we make a purchase from a retailer, manufacturer or service provider. Loosely speaking, they exist to give people confidence that the product or service offered is proven, up to the job it's designed for and is not going to break within a specified period of time.

Correct me if I'm wrong, but here are what I understand the definitions to be (when talking about products/items) :

  • Guarantee
    A manufacturer or retailer will usually fix a faulty product, if it fails while in it's under guarantee, or they might replace the product completely with a new one. The guarentee period if usually set by the manufacturer.
  • Warranty
    An insurance policy, sometimes offered 'free' as part of a purchase, but also available as a paid-for extra.

How does it work?

When building a new house, in order get it signed off as habitable and in order to get a mortgage on it, there needs to be a 10 year warranty in place. The two main providers of these are NHBC and Premier Guarantee. The latter one being who we've chosen to go with for this project.

These are basically paid-for insurance policies to cover yourself (and your mortgage provider) in case anything happens to the house which needs repairing or replacing in it's first 10 years. Usually the builder will cover a period of time, immediatly after completion, but for the longer term, these warranties take effect. They're not cheap, but they're more affordable than having to pay for a roof to be re-built, or foundations to be strengthend, for example.

During the build, starting right from day one, a surveyor is instructed to check the designs and structural calculations, to make sure that everything is going to be strong enough. They will be involved right through the build progress and will check everything along the way.

So what's up?

As you know, this house design involves retaining walls to hold back the soil on three sides of the plot. Two of these walls are integrated into the house itself and double up as the external walls of house. Structurally this is sound and occurs all the time in construction engineering, but in order to prevent water/damp coming through the walls into the house, the outside of these walls have to be 'tanked'.

Tanking basically means that a waterproof membrane is stuck to the outside of these walls and a drainage system is used to divert any water away. After so many years (decades) of designing and improving these tanking systems, people still get nervous about using them. Water and damp are so difficult to keep out that you can literally spend a fortune, and still end up with problems. Just watch a few self-build TV shows like Grand Designs and you'll see what other people have come up against.

With all the flooding that this country has been experiencing in recent years - especially this year - insurance companies are getting increasingly less willing to cover properties near water, with a possibility of flooding or that have underground elements. And that's exactly what we're experiencing with this project.

The warranty provider wants to make sure that it doesn't have to pay out, by getting a guarantee from the designers / suppliers / builders that the tanking will be sound. So this is where it gets complicated.

Here are all the people involved, where the tanking is concerned:

  • Builder
    The people who will install the tanking.
  • Membrane supplier / manufacturer
    The people who make the waterproof membrane system (they have even offered to train and qualify the builder to fit their product).
  • Designer / engineer
    The people who have designed the retaining wall / house and have specified the selected brand of tanking.
  • Main warranty provider
    The people who will be covering the finished house, to pay for any repairs for build defects.

The problem is, as the builder has put it, "everyone is kicking the can around the playground, but nobody wants to pick it up". The main warranty provider wants the builder to provide a guarantee. But builder believes it should be the designer's responsibilty, as they have designed the wall and specified the tanking system. The main warranty provider also wants us to hire a tanking specialist, to write a report, to certify that the design is sound. This could cost a lot more money, and we don't have that kind of spare cash in the project to justify it. If the designers know what they're doing, it should all be fine - and they will have Professional Indemnity insurance to cover them, should anything go wrong.  

Plus, the manufacturer should give a guarantee on their product - but they want to charge a lot more money for this too. This part I don't understand... If the manufacturer is selling a product AND they are going to be certifying the builder to install it to their specification, shouldn't they offer a guarantee as standard? Why are we having to pay a load more cash? Basically it means we are paying for insurance twice - once for the membrane manufacturer to cover themselves and once for the Warranty provider to cover themselves, so they can cover us!

Craziness! It's a whole mega daisy-chain of insurance because nobody's prepared to take responsibilty for their work or take on the risk.

I can understand it from some points of view... but others leave me baffled.

Next entry: Building our Eco knowledge at the EcoBuild show London (Thursday 6th March 2014)

Previous entry: The calm after the storm (Sunday 16th February 2014)

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