Hello
We will erect our house where the construction company will install the first layer of insulation + vapor barrier. Then we'll take over and do the final layer ourselves (45.insulation+boards). Is there any point in conducting a pressure test? I will be able to see how the vapor barrier is installed and I'll be careful with the final layer. Is pressure testing mainly to ensure that the builders haven't cut corners before they hide everything with boards or is there some more fundamental/hidden fault that can be found?
We will also have an exhaust air heat pump and then you will still make holes all over the house for supply air vents, so I'm also a bit unsure what benefit pressure testing will provide in such a house?
We will erect our house where the construction company will install the first layer of insulation + vapor barrier. Then we'll take over and do the final layer ourselves (45.insulation+boards). Is there any point in conducting a pressure test? I will be able to see how the vapor barrier is installed and I'll be careful with the final layer. Is pressure testing mainly to ensure that the builders haven't cut corners before they hide everything with boards or is there some more fundamental/hidden fault that can be found?
We will also have an exhaust air heat pump and then you will still make holes all over the house for supply air vents, so I'm also a bit unsure what benefit pressure testing will provide in such a house?
Good thoughts!
And as you write, whether the fresh air only comes in through the wall vents or also through some leaks in the vapor barrier shouldn't matter much.
It's mainly when building passive houses/low-energy houses with heat recovery ventilation (FTX) that you want to ensure the air doesn't take the wrong path. For example, that you suck in cold air through leaks instead of pre-heated fresh air from the heat exchanger.
So, no, I wouldn't bother with a "blower door test" in your situation.
And as you write, whether the fresh air only comes in through the wall vents or also through some leaks in the vapor barrier shouldn't matter much.
It's mainly when building passive houses/low-energy houses with heat recovery ventilation (FTX) that you want to ensure the air doesn't take the wrong path. For example, that you suck in cold air through leaks instead of pre-heated fresh air from the heat exchanger.
So, no, I wouldn't bother with a "blower door test" in your situation.
I would pressure test without hesitation. I have seen how they cheat with the diffusion barrier. If you use exhaust air and have leaks, you will eventually notice this as black dirt streaks in corners and angles. You only build once, so don't skimp on the wrong things.
No, you can't see everything with the naked eye. I have seen examples of tape that is approved for building plastic that releases as soon as you start pressure testing. So I'll say it again, don't skimp on something so important. It's not particularly expensive in the grand scheme of things.
I can add that I have quite a lot of trust in the construction company which is local and has a good reputation, so I'm not too worried that they will cheat. However, it is after all a construction company, so there might be some negligence that can occur, but not outright cheating.