Insulation between bathroom and exterior wall of house

[greatscot1]

Not really sure where to post this but here we go...

I'm helping with my folks houses insulation at the moment, I've insulated the loft to the full depth, they are just about to get cavity wall insulation installed (not really sure if it is a good thing taking away that moisture barrier, but it's going ahead anyway..... ) but the bit thats left is a strange area between the upstairs bathroom and the outside wall. It is an area where there is no wall as such (compared to the rest of the house). There is a tiled area on the outside of the house. No wall as such and very little except a gap between the decorative tiles on the outside and a pine facing in the bathroom.
It's about 10 feet long, 4 feet high with 1 foot gap between the pine facing inside the bathroom and the tile facing on the outside of the house.

My question regards insulation.
What is the best insulation to stuff into the one foot gap?
Standard glass fibre rolls, recycled plastic or sheeps wool?

I'm drawn towards sheeps wool insulation as in naturally breathes.
Any opinions?
I don't want to create a dampness barrier by installing glass fibre or recycled plastic.
Am I correct to be drawn towards sheeps wool based insulation?
Any problems with this?
By the way there is no plumbing or piping of any sort in the gap. So no worries about freezing.

Thoughts?

 

[mointainwalker]

Best ? Well that's rather a subjective matter.

I think the insulation value of these materials is similar, with wool being a little lower and plastic, maybe a little higher.

Cost : Wool will cost you at least four times as much, but if you like natural and helping farmers , fine.

Practicality: As roll material , all these are floppy so you will have to secure it in place using nails, wires, netting etc or it will compress with time leaving a cold spot at the top.

You can buy the fibre-wool stiffened ( called "batts" ) so it stands up on its own at about twice the roll price.

You are wrong when saying

"you don't want to create a dampness barrier "

That is exactly what you do want to do if you are interested in insulating.

Prior to replacing the pine facing, you should stretch and fix a plastic film/sheet across the whole face. This is to stop moist air passing through and then condensing in the insulation.

Did you install a moisture barrier between the ceiling and the insulation when you did the loft ?

 

[greatscot1]

You are wrong when saying

"you don't want to create a dampness barrier "

That is exactly what you do want to do if you are interested in insulating.

Prior to replacing the pine facing, you should stretch and fix a plastic film/sheet across the whole face. This is to stop moist air passing through and then condensing in the insulation.

Did you install a moisture barrier between the ceiling and the insulation when you did the loft ?

Thanks for your reply.
I didn't install a dampness barrier in the loft.
I suppose I will just use the re-cycled plastic stuff for the bathroom. I hate itching!!!

I didn't want to take the pine facing off as there are tiles on a part of it. I was just going to take the top shelf off(that runs along the top parallel to the window sill) and stuff the insulation into the 1 foot gap.
I've used the starwberry netting technique before in another house to do behind lath and plaster walls and it worked a treat.
Unfortunately I don't wish to re-tile and re-do the pine facing. So fitting the netting will be tricky.
I'll have a look at these batts and installing a dampness barrier sheet behind the facing.

 

[mointainwalker]

The itchy yellow stuff has been superseded.

When I bought some Knauf roll three months ago, they were just introducing the new roll made of something they called Ecose. Brown and completely non-scratchy.