Loft insulation - Bin old insulation or keep it and put new layer on top?

Mutton_Geoff

Anyone who suggests getting rid of the old has probably never worked in an old loft. There is virtually no benefit getting rid of the old stuff unless you have other work to do up there, new lighting installs etc.

Just lay the new stuff over the old (the new stuff will be higher than the joists in any case. You can usually get someone in for around £200 (grant assisted) to do it. Just look at your (or any) energy suppliers website for more info.

SailorSam

When we had the loft done about 3yrs ago they just layed it on top of the old stiff. When B&q had insulation on offer for £1 a roll recently i bought more and am only going to top-up again. I wouldn't dream of throwing away the old stuff.

ic

Having laid insulation in two lofts, I can tell you that you don't want to be in the loft for longer than is necessary, its a horrible job. As for the comment above about the old insulation preventing the new from working, what utter rubbish. The more layers of insulation you have, the warmer the house will be.

Wetkitten

In response to JackRS's question, I would recommend buying from Wickes - rolls are easy enough to split down to size once you get the hang of it.

Current Building regs recommend 270mm (11 inches) so you run one roll between joists and then another across on top.

I didn't find it too bad and I'm a laydee! Just make sure you are covered up with gloves and mask, have a stanley knife to cut, a broom handle to manoevre rolls into position, a board to sit/stand on and a light. Done in a few hours.

Seamonster_2

Old thread, I know, but I have a loft insulation query if anyone can help...

My loft was professionally insulated about four years ago. Unfortunately, the insulation got soaked and covered in dirt when the roof was power-washed last week and a lot of water leaked in through the roof tiles.

The lagging is still wet several days later. Would it be best to get it totally removed so the underlying boards can dry out before having new stuff laid? Or could it eventually recover, and I could just lay new lagging over the dirty sections?

keystone

It ain't going to dry and will give all sorts of downstream (excuse the pun - ahem!) issues if you just leave it. You'll have to replace it methinks.

Cheers

27col

The fact that the insulation is dirty is hardly a reason to change it. I would think that it would dry out without too much trouble. Any pressure washing that I have ever done did not actually use a large quantity of water. The work is done by the pressure of the water, not it's quantity. In any event I would wait a while to see if the insulation does actually dry out. Insulation is a very difficult product to dispose of, especially fibreglass. It does not burn or rot down so it is difficult to get rid of. When I built my house I removed a large amount of dirty old insulation from the house that I was demolishing. It was filthy and I tried to burn it without success, so I stored it and replaced it in the new house. Then covered it with new insulation to make up the levels required these days.