DIY Airtightness test (the Blue Peter method)

[Dudda]

I think I’m going to give this a try in a month when I’ve all the airtight stuff finished (which probably means two months as everything is taking twice as long as I plan). I’m not really interested in recording the figure or trying to get the pressure correct as I don’t have a U tube manometer or anemometer and don’t want to spend money on this just find the main leaks before I pay for a full blowdoor test. 

 

Semi related. Do you have to do an official registered blowdoor test on a new build in the UK? You do here in Ireland for the last number of years but the target isn't currently high although they plan on reducing it soon.

[jack]

10 minutes ago, Dudda said:

Semi related. Do you have to do an official registered blowdoor test on a new build in the UK? 

 

Yes, you do.

 

Edited July 3, 2017 by jack
Added linky

[ProDave]

1 hour ago, Dudda said:

I think I’m going to give this a try in a month when I’ve all the airtight stuff finished (which probably means two months as everything is taking twice as long as I plan). I’m not really interested in recording the figure or trying to get the pressure correct as I don’t have a U tube manometer or anemometer and don’t want to spend money on this just find the main leaks before I pay for a full blowdoor test. 

 

Semi related. Do you have to do an official registered blowdoor test on a new build in the UK? You do here in Ireland for the last number of years but the target isn't currently high although they plan on reducing it soon.

You would now, but as my house is being assessed to the 2013 version of building regs I don't need an official certificate to get a building control completion certificate.

 

I suspect not having an official test will make my as built SAP worse as they will have to use an assumed air tightness figure.

[Ian]

11 minutes ago, ProDave said:

 

I suspect not having an official test will make my as built SAP worse as they will have to use an assumed air tightness figure.

It will make it a lot worse as the assumed air tightness figure is 15m3/h.m2

Edited July 3, 2017 by Ian

[gravelld]

1 hour ago, jack said:

 

Yes, you do.

 

 

... but not _every_ newbuild - if you're building a lot, only a sample (1/3 or 1/4, can't remember which) of the distinct "dwelling types" is required.

 

And of course the test is irrelevant in many cases because the tester is paid for by the developer (conflict of interest) and its just bodged onsite with any sealing removed subsequently. Not in *all* cases... but certainly in some.

 

Only way to be sure is to pay for your own independent assessor.

Edited July 3, 2017 by gravelld

[Jeremy Harris]

16 minutes ago, gravelld said:

 

... but not _every_ newbuild - if you're building a lot, only a sample (1/3 or 1/4, can't remember which) of the distinct "dwelling types" is required.

 

And of course the test is irrelevant in many cases because the tester is paid for by the developer (conflict of interest) and its just bodged onsite with any sealing removed subsequently. Not in *all* cases... but certainly in some.

 

Only way to be sure is to pay for your own independent assessor.

 

 

Sadly this is probably true.  When we were looking for a builder we went to look at a small development of 6 houses that were being built, at the invitation of the builder.  Part way through the tour, the "sales chap" that had been showing us around the most complete build had to go and answer a phone call.  There were two chaps inside taping things up, and I asked what the air tightness target was that they were aiming for.  One of them said that the house had been tested twice and failed, and they were busy taping it up to try and get a pass.  The other remarked (sounding a bit pissed off) that they weren't going to go through all this hassle on the other houses..............

 

 

Edited July 3, 2017 by JSHarris

[gravelld]

I would pay £200 for a rough and ready testing kit (i.e. a fan and mount), without manometer, if anyone fancies setting up a part time business and a kickstarter account...