Air Tightness Test - New Build A2 Rating

gandalfio

Hi,

Can this test be performed/signed off on before the plumbing and heating systems are operational/commissioned?

the_amazing_raisin

Can't see any reason why not but it might be better to ask the the general Construction and planning forum, I think there's a few folks over there more familiar with the process

Calahonda52

Depends on the tester, an his attitude to risk of being mislead.

I know some testers won't do the final until all trades are off site, (and the sky dish is fitted).

mike_2009

You would normally do three tests, before 1st fix, after all trades finished / penetrations completed to find leaks, then a final one for signoff. I wouldn't want anyone to sign off in advance of trades work, you'll be living in the house for years, what have you saved vs what has it cost you in heat loss?

gandalfio

https://www.boards.ie/discussion/comment/120323643#Comment_120323643

This is what I can't understand. The test was done 2 days before plumbing and heating were operational in the home. It was also done before we snagged and 2 weeks before the build was completed. It was also carried out before the BER assessment was done. Should the BER have been done before the ATT?

The result was 4.51 m3/(hm2) at 50 Pa. From my understanding this is a bad result and it should be under 3 for a new build A2 with mechanical ventilation.

Calahonda52

ATT is an input into the Final BER

THE ALM

Whether the heating was operational will have no effect on the result as you are testing how air tight the house is so unless the heating and plumbing required holes to be put in the envelope of the building it wouldn't matter. It will have an effect on the heating of the building if it is drafty and how much it is going to cost you going forward.

The one before you snagged and before the build was completed would be the important ones and they should have shown where any air leaks are and could be remedied at that stage. As Calahonda52 says the ATT results would have been used in the final BER.

We just got an ATT competed on Friday and have just received the results of 1.376 for a 2006 bungalow. We did carry out a few upgrades and the tester was a bit surprised to be getting such a good figure.

Scoopsire

@ALM what type of upgrades did you do?

gandalfio

Where abouts on the report does it state where the leaks are coming from? Section 4.0, Findings and Observations, just gives the result of 4.51, and then a couple of sentences stating the result is within the upper limit of 5.

gandalfio

Also, should the builder have remidied the leakages given the bad result?

keno-daytrader

A horrible result in this day and age, you shouldn't settle for anything over 2.0 at bare minimum, that result will really cost you in the years to come if you dont rectify it now.

Anyone signing contracts of a new build should have minimum airtightness stipulated in the contract.

THE ALM

https://www.boards.ie/discussion/comment/120324539#Comment_120324539

It started with the small jobs that I could carry our myself which included removing 35 downlights, cursed drafty things, and filling the holes. Then armed with expanding foam I went round the entire house looking at all the holes inside and outside the building envelop, the pipes that go up from the hot press into the attic being a particularly leaking area and the attic staircase being another one.

The big one last Sept was replacing all doors and windows with triple glazed and composite doors, the old ones were never great and this was a long planned change. When they were fitted I asked the guys to leave off the internal window cills as I wanted to improve the insulation down into the cavity and make sure it was properly sealed.

THE ALM

https://www.boards.ie/discussion/comment/120324546#Comment_120324546

It doesn't. When the test is being carried out the leaks should be identified when the house is pressurized. When ours was done the tester and myself went round the house feeling for drafts, they are quite noticeable as our attic staircase proved.

Before the test was carried out I went round with an incense stick (smoky) to see if I could find any drafts that I missed filling holes.

gandalfio

Is it feasible that a house with a 4.51 ATT result be given a BER of A2?

keno-daytrader

Yes, we got a BER for our new build, our airtightness was under 1.5 and the BER assessor didnt even ask for the cert or the number, I suspect he just inputted some preset airtightness # We got an A2 rating, we could have had an airtightness of 10, bit of a joke.

The whole BER thing for us was a waste of time but we had to have it so paid the 250 fee, a useless piece of paper that sits in our newbuild file.