Loft PIR Board Removal

[glenmore3685]

Hello,

I'm always grateful for the wealth of knowledge on this forum so I'm looking for some advice regarding PIR loft insulation boards.

We bough a house just under a year ago and the surveyor flagged that there were some issues with condensation with the PIR insulation boards in the attic .
Having gone up into the attic this morning to check something else, I noticed quite a few damp patches where the condensation has formed. I assume the required gap wasn't provided when the insulation was installed - nevertheless I believe my best course of action will be to remove the boards.

Would removing these boards be possible for a DIY'er? Some quick searching reveals that they aren't toxic or dangerous to health and I can see they're held in place with screws so I'm assuming it should be fairly straightforward?

I'd welcome any advice anyone has.

Thanks

[LooneyTunes]

Dead easy to remove. Just pull them and the sheets will probably come out intact. Just wear a mask/goggles as the dust isn’t super pleasant.

If the issue is simply that there’s no air gap, pull the boards out and put them back in leaving an appropriate gap? You might need to buy a little bit more to deal with any extra infill needed, but it cuts easily with a hand saw.

[glenmore3685]

LooneyTunes said:

Dead easy to remove. Just pull them and the sheets will probably come out intact. Just wear a mask/goggles as the dust isn t super pleasant.

If the issue is simply that there s no air gap, pull the boards out and put them back in leaving an appropriate gap? You might need to buy a little bit more to deal with any extra infill needed, but it cuts easily with a hand saw.

Yeah thanks LooneyTunes, that's sort of what I wanted to hear. I'm not sure I wouldn't mess up re-installing them - my main objective is to prevent any additional damage at this stage. There is already insulation above the ceiling so not sure how much I'd notice losing the roof insulation....

[Domski86]

If this in an unheated/non converted loft with rockwool at ceiling level (floor of loft), you shouldn't really have any rafter insulation. This is a cold roof design that's had a bit of extra insulation chucked in the wrong place. As you rightly said there probably isn't enough of a gap for air/moisture to vent out, the PIR is causing warm air to condense at the wrong spot and run down the PIR, wetting your rafters.

By all means top up the floor/ceiling level insulation, but unless you're converting this space and adding a proper vapour control layer by taping all the joints etc that PIR needs to be removed. It doesn't look like it would take much, just find an edge and pull it, most older stuff shrinks a little so will likely come out without much effort

[wolfracesonic]

^ Some felt lap vents might be a good idea as well, as it seems warm moist air is finding its way up there, which is not unusual tbh.

[shtu]

They'll just tear out. Go nuts.

Part of the problem is the foil side is a vapour barrier too, so the moisture rising from below is getting caught there and condensing. You're better off rid of those, and some more glassfibre in the traditional place.

[TA14]

PIR is much better at ceiling insulation than what you appear to have so I wonder whether you could re-use it there.

[megaphone]

I have PIR boards laid across my joists, I then stack all my crap on top of them.

[glenmore3685]

Thanks for all the comments. I've started ripping them out this weekend. As mentioned it's pretty straightforward. Disposing of the boards will be likely be the most challenging part - I'll easily fill a skip with what I pulled out today and there is more to go...

[glenmore3685]

TA14 said:

PIR is much better at ceiling insulation than what you appear to have so I wonder whether you could re-use it there.

This is an interesting idea, I might look into removing the last few a bit more carefully and seeing if I can use any to lay over the tongue and groove.

[Magooagain]

Expensive insulation that. Would be a waste to throw it out.