Airtest tomorrow - eeek

[Adamantium]

Hi all,

 

 Have an airtest being done tomorrow.

 

Any tips on how to grease the wheels in my favour?

 

I genuinely have no idea how it will pass. Primarily because the loft isn’t really finished.

 

 Any help would be much appreciated

 

 

[nod]

I would worry He will ask what score you need to achieve and be within that 

[Adamantium]

You would worry or you wouldn’t?

 

i upper my solar to 5.6kwh to give me a bigger safety net.

 

don't know what my target is.

 

[JamesP]

Is this for a new build EPC?

We scored 91 - B without an air test as was told it was not necessary. For an additional fee however for an air test it would score an A.

Average rating in England is 60.

Don't worry.

[Adamantium]

It’s for a new build.

 

i was told it’s unavoidable and the chance of passing is next to zero unless we can ignore the top floor somehow.

[Roundtuit]

Why have a test before you're ready?  For a new build, I'd be aspiring to much better than a scrape through...

[Adamantium]

Because the builder scheduled it before lock down as we were receiving pressure to have the building signed off for the purposes of completing the CIL exemption and the warranty.

 

can I ask, if it passes, what difference does it make how good the result is or isn’t?

 

isn't it just a rubber stamp exercise?

[SteamyTea]

13 minutes ago, Adamantium said:

 

isn't it just a rubber stamp exercise?

As I understand it, yes, just a rubber stamp, pass or fail.

Pretty hard to fail in reality if some care has been taken.

If there is a known problem, explain to the people that are pushing you to get it done that the country has been in lock down for 3 months, just in case they missed it.

A few insurance companies are in Bournemouth, so they may have been on the beach.

[Ian]

53 minutes ago, Adamantium said:

can I ask, if it passes, what difference does it make how good the result is or isn’t?

 

isn't it just a rubber stamp exercise?

It’s certainly not a rubber stamp exercise if you’re simply aiming for min building regs compliance because failure to get the air tightness value set out in your initial design can really complicate things.

[Roundtuit]

55 minutes ago, Adamantium said:

can I ask, if it passes, what difference does it make how good the result is or isn’t

Airtightness is important to the performance of your house in terms of heating requirement and comfort levels.  In simple terms, you don't get the full benefit of your insulation if the air is bypassing it.

[Declan52]

1 hour ago, Adamantium said:

 

 

can I ask, if it passes, what difference does it make how good the result is or isn’t?

 

 

A pass with a score below 1 means you have done a serious amount of work and will benefit in reduced heating bills as it's not leaking out quicker than you can replace it.

A score near 10 means you haven't fitted a front door. That's the kind of air leakage your talking about. You wouldn't want to live in a house with the front door missing.

[Adamantium]

Thanks, that’s a helpful explanation.

 

 My house has been very much sealed throughout. It’s not passive house standards but there’s no noise or drafts.

 

i have mvhr throughout as I did not want trickle vents, and suspended ceilings which join the wall cavities. My fear is every wire poking through into the ceiling void, every speaker, down light or mvhr vent.

 

 My biggest concern is they doors that seal the crawl space. 
 

guess I’ll find out today, but thanks as now I know what the results mean.

 

 Not sure what the target is though.

[SteamyTea]

You will need to block off the MVHR.

[Gone West]

We had an initial test done before the house was finished to give us an idea of where any problems might be. It was very good but the tester wouldn't accept it as the final test because the house wasn't completed enough. You can always fix any problems and have another test done later.

[Adamantium]

Looks like that’s what’s happening.

 

 Failed the test but the numbers were not what I was expecting.

 

 Target was 70?

 

 Just missed out.

 

 They are coming back next week after some suggestions have been carried out.

 

wall hung toilets, lots of downlights Los off mvhr vents, lots of ceiling speakers, air con vents, underfloor heating manifolds behind cupboards.

 

 Also cupboard doors to access the crawl space isn’t helping.

 

 We will get there but not today.

[joe90]

When we had our test I went round with jos sticks and a gun of caulk as the smoke trail was good at identifying leaks. What if you de pressurised the house with a home made fan from a car to test yourself rather than the cost of the test in case you have more leaks.

[Adamantium]

Probably a good idea. Thanks.

[Mr Punter]

Is it the case that you have a ventilated loft and holes in the ceiling?

 

You can often just seal over these for the test.

 

The test result should be something between 1 and 20.  You should be able to achieve 5.  It is for air permeability and is in m³ / (h.m²) @ 50 Pa.

[Declan52]

Can you get access to the top of the downlights and ceiling speakers to place a air tight hood/plant pot over them??

Mhrv vents should have all been sealed over before the test.

Air con vents???

You can use rubber seals on the crawl space hatches then use a screw with a decorative cup and screw threw the door stop to pull the hatch tight against the seal.

Can you use a bead of silicone to seal where the toilet comes through the wall?

A few pics of the manifolds and the ceiling speakers and toilet would give us a better idea of what needs done to fix it.

[Adamantium]

Mvhr sealed over completely.

 

 Could probably get behind the downlights, there aren’t that many.

 

6 wall hung toilets, the frame is very open to the wall cavity where the soil pipe drops. They’ve been foamed, rockwooled and siliconed, 

 

i think the loft is the issue, rubber seals have to be the way.

 

 It’s a big house, massive amount of work to seal.

 

 Why is my target 70? Sounds like a different scale.

[Gone West]

11 hours ago, Adamantium said:

Why is my target 70?

It would be easier if we knew 70 what? Is it m3/h.m2 @ 50Pa or ach @ 50Pa, SAP uses the former and nearly everyone else uses the latter.

[A_L]

11 hours ago, Adamantium said:

Why is my target 70? Sounds like a different scale.

 

Remember you can always use a default value of 15m³/m².hr (Part L1A 3.22b)

[ADLIan]

Is '70' a typo error, should just be '7'?

 

Problem with using the default value of 15 is that it probably results in a failure under Part L1A.

[Ian]

For anyone who is reading this who may be wondering what order of airtightness is normally achievable on a new build if you don’t use any special tapes or air tightness membrane I achieved a value of 3.7  m3/h.m2 @50Pa on a new-build timber frame bungalow. That’s without taking any special precautions regarding airtightness as the building is naturally ventilated (no MVHR). 

Edited June 27, 2020 by Ian

[DevilDamo]

That is good. We achieved 4.1 for a detached traditionally built large chalet bungalow yesterday.

 

Edit: Although 3,500sq.ft is quite large for a chalet bungalow hence the ‘large’ comment.

Edited July 2, 2020 by DevilDamo