another olft insulation q, should I get rid of existing

lobbyludd

the existing insulation is less than 5cm thick, filthy, fibreglass/mineral wool (i'm assuming, it was old and filthy when we moved in 11 years ago).

I've got new to put between the joists and a top layer to overlay -

Is there any benefit to overlaying the new on the old, or am I better off getting rid of it?

lobbyludd

not to worry, been up with a bigger torch and some boards to get to the recesses, it's a mess, so answered my own query

cyclonebri1

If you are buying new, (we are too), remove the old.

Lay new at 100mm between the joists.
Cross lap as you say with the next 200mm.
Anything you can salvage can then go on top and help in cooler rooms

ed110220

I removed all the original 1949 glassfibre insulation from the loft as it was so crushed, broken up and filthy and full of debris that I thought it would be best to start from scratch. It's a horribly messy job and filled about 30 black plastic bin bags (put out over several weeks ;-))

Yorkie1

If you do decide to remove it, do not shower in hot water afterwards. Use cool water to get rid of any fibreglass bits first or your pores will open up and they'll go into them!

ed110220

Yorkie1 wrote: »

If you do decide to remove it, do not shower in hot water afterwards. Use cool water to get rid of any fibreglass bits first or your pores will open up and they'll go into them!

Never heard that before! I didn't notice anything wrong having a hot shower after removing the old insulation.

sk240

I personally wouldnt bother removing the old, just overlay the new, you will still gain a fair bit thermally than if you removed it.

greyteam1959

I would leave the old stuff where it is......flippin' horrible filthy job to get rid of it.
It will be a small benefit........

cyclonebri1

As above, every little helps says Tesco;);)

Done 1 today, full suit, mask and goggles.

And yes, I am still itching:o:o