Insulation foam recommendations?

amsbam1

Looking to get Insulation foam between the rafters of the extension i'm building. Anyone with recommended person to do this?

Does this come in both open cell and closed cell forms? I guess the closed cell form is a bit steep in price. So maybe makes sense to use the cheaper open cell for between rafters.

I'm based in Dublin

Gumbo

Cheaper not always the best.
Study the agreement cert and DoP of the product you are using and ensure strict installation to it.

Ventilation and air movement is key here to the time structure.

sydthebeat

amsbam1 wrote: »

Looking to get Insulation foam between the rafters of the extension i'm building. Anyone with recommended person to do this?

Does this come in both open cell and closed cell forms? I guess the closed cell form is a bit steep in price. So maybe makes sense to use the cheaper open cell for between rafters.

I'm based in Dublin

im not quite sure why youd think closed cell is a better option than open cell.....

especially in a timber application

Calahonda52

https://tigerfoam.com/sprayfoaminsulation/open-cell-vs-closed-cell-foam-which-should-i-choose/

The only foam I ever use is Gillette to go with this
https://gillette.com/en-us/products/gillette-labs/heated-razor-by-gillette

The issue when used on external timber structure is that water can condense against the timber, for either open (high risk) or closed (lower risk) and thus accentuate the risk of rot.
The other risk is unless you are there, how do you know which one you got

amsbam1

sydthebeat wrote: »

im not quite sure why youd think closed cell is a better option than open cell.....

especially in a timber application

I presumed closed cell is more expensive - better insulating but poorer breathing.

Breathing is nice to have for between rafters so I guessed open cell would be better.

What do you think?

amsbam1

Calahonda52 wrote: »

https://tigerfoam.com/sprayfoaminsulation/open-cell-vs-closed-cell-foam-which-should-i-choose/
https://b-static.net/vbulletin/images/icons/icon7.png
The only foam I ever is Gillette to go with this
https://gillette.com/en-us/products/gillette-labs/heated-razor-by-gillette

The issue when used on external timber structure is that water can condense against the timber, for either open (high risk) or closed (lower risk) and thus accentuate the risk of rot.
The other risk is unless you are there, how do you know which one you got

My roof is a tiled roof - so breathable. Condensation will rise towards the roof of course however ideal is if most will then evaporate through the tiles. So thinking Open Cell is the cheap and cheerful solution for me.

Now just need to find someone who'll do it for me for a good price. :-):)

horse7

amsbam1 wrote: »

Looking to get Insulation foam between the rafters of the extension i'm building. Anyone with recommended person to do this?

Does this come in both open cell and closed cell forms? I guess the closed cell form is a bit steep in price. So maybe makes sense to use the cheaper open cell for between rafters.

I'm based in Dublin

I used these guys, found they do a good job and very pleased with the results, much better than fiberglass insulation or rockwool.
snip

Calahonda52

amsbam1 wrote: »

My roof is a tiled roof - so breathable. Condensation will rise towards the roof of course however ideal is if most will then evaporate through the tiles. So thinking Open Cell is the cheap and cheerful solution for me.

Now just need to find someone who'll do it for me for a good price. :-):)

How did you deduce this?
Is the felt under the tiles breathable?
Is it counter battened?
are the soffits ventilated?

amsbam1

Calahonda52 wrote: »

How did you deduce this?
Is the felt under the tiles breathable?
Is it counter battened?
are the soffits ventilated?

Sorry for the slow reply. You ask very interesting questions. I have breathable felt, no counter battens, no soffit vents. Why did you ask these specific questions?

I have decided to go with Open Cell (with a gap between felt and insulation if that's cheap to do) - because of condensation management.

Not too bothered by having a bit of mould growing on the felt, but want to balance minimising mould issues and keeping cost down.

BryanF

If you don’t have counter battens you need to leave an air gap under the breathable felt.