Water pressure test

[Acchillo]

Hi,

we need to run a drain pressure test for the building contron inspector (final visit). I am told that he wants to seal the drains on one end and fill up the water circuits with water to check leaks.

three questions:
1) It is a two storey semidetached house. I guess this will have to be done from the ground floor as if we fill up the pipes from the first floor there could be overflow on the ground floor system. correct?

2) the drainage system has been installed properly (you can never be 100% sure). what are the chances it will break to a pressure test. How tough is the pressure test on the pipes?

3) The extension we built is now complete with flooring installed. I have the impression this is a late request from the inspector, as it would be extremely difficult to repair any problems (i.e. re-expose the drains and the foundations). He is undoubtedly entitled to the demand. Byt any views on this?

 

[Richard C]

Testing should be completed at first inspection before backfilling, did your BI not inspect then? did you ask them to? I’ve just completed a drain run for a new 1st floor en-suite & when the BI came to inspect the trench, backfill, drain run & all the upstairs waste runs, I broached the subject of testing; she just said to go ahead that’ll be fine. A friend of mine also does new builds (same LABC) & he’s never been subjected to a witnessed test either, just had to supply details of a water test retrospectively. You should only need to test the drain run from the downstairs loo to the inspection chamber as the upstairs is not subject to standing water pressure head, the water would overflow out of the downstairs loo before that!

You may have been a bit unlucky with your BI but they should have made clear their requirements for a witness test on initial inspection (assuming there was one!) & while the run was still exposed. Details of test requirements can be found in Part H of the building regs. & you can download these free from the professional user section of the Planning Portal website. There is an alternative air pressure test but this obviously requires hire of the test equipment. Read the regs. as it will give you an idea of what HE is expecting YOU to do; you may also be able to satisfy your BI by other means. A leak big enough to fail is extremely unlikely if the pipe runs have been properly installed & not damaged by ham fistedness; but it'll be a bummer if it does fail!