Insulation Advice Please

CarolineL · 27-11-2021 1:20pm #1

We're in the midst of an insulation job on a storey and a half house. We have a reputable company doing the work but I'm so afraid of mould and damp in the future. We have slopes in the ceilings in the bedrooms and they are pumping rockwool in same. I've told them my concerns and owner has assured me it will be fine. They have installed more air vents in the attic but none down in the slopes. They also want to cut out hollow walls inside and place earthwool in same. Are my worries right or should I just relax and let them on with the job? All advice greatly appreciated. Thank you.

Biker1 · 27-11-2021 2:47pm

https://www.boards.ie/discussion/2058220056/insulation-advice-please

Sounds like they are full filling the sloped sections which is a no no. There must be a ventilation space between the insulation and felt in order to prevent the rafters from rotting. They will have to cut into the side walls in order to gain access for installation of the insulation in the crawl space and knee walls. S.R.54:2014 is an excellent guidance document and if they are any way professional they would have a copy for reference.

CarolineL · 27-11-2021 5:32pm

Thank you. I feel physically sick. Knew I was right. Are we rightly screwed? Can this be rectified? He has one side of house done. How soon before we start seeing the negative effects of this? Will mould start in ceiling or roof? Also I'm annoyed over they put 2 plastic air vents in the attic over the front window which is a total eyesore. One is for attic insulation and the other for a mechanical vents for the shower, which they installed. They told us they would try put in them in the gable ends of the house. I'm after driving around this afternoon and I don't see any house with vents like this. Many a house has roof vents. Is this what they should have done? I could cry. I trusted them. I know if I challenge him on the rockwool filling in slopes, he will just say vents in attic will suffice. Where can I find that link please? Please advise on what I can do? Is it OK to let them cut holes in hollow walls and lay down earthwool? Seemingly when they pumped the walls, the beads came through to one of the hollow walls. So they have to be vacuumed out and then the earthwool put down. What would you do if in my position please? They are due to finish works Monday and I need to pay then.

muffler · 27-11-2021 6:36pm

Agree with Biker1. You really need to stop your builder immediately and employ an engineer or energy consultant to look at whats been done, adjust same and plan a method for completion.

In the meantime have a read from Page 32 onwards of Technical Guidance Document L.

This will also give you a wee bit of an insight as to what's required.

CarolineL · 27-11-2021 7:41pm

Should he not have pumped it into slopes? Is rockwool not breathable? Is it OK for him to cut panels from internal hollow walls and put down earthwool or pump rockwool either?

muffler · 27-11-2021 7:59pm

https://www.boards.ie/discussion/comment/118233142#Comment_118233142

Without knowing the exact roof makeup and type of insulation (you sure it's Rockwool?) Id be fairly certain that there will be a need for a 50mm ventilation gap next the felt.

What do you mean by hollow walls?