?Bagged? loft insulation

[Tim+]

By ?bagged? I mean the insulation is enclosed when unrolled.

I?m finally getting around to topping up our loft insulation but because our boiler is at the far end of the loft, I need to maintain access to it.

There?s not enough headroom to use legs to raise the bit of flooring that presently provides access so I was wondering if there?s a form of insulation available now the I could just roll up easily when I want access and then replace afterwards.

Wicked used to do Knauf Space Blanket but not any more it seems.

Anyone know of a similar product?

Tim

[Theo]

works out about 3x as expensive as regular insulation though.

An alternative plan is to wrap insulation in similar film. Somebody mentioned there are condensation issues (use breathable film?) so would need thinking about the temperature gradient.

(I found a really good calculator of insulation performance here:

tells you things like U value, decrement delay, condensation, etc, for any arbitrary insulation stackup)

Theo

[Andy Burns]

I used Space Blanket as a top-up layer when the energy co's were practically giving it away, B&Q may have cleared all theirs out too

[www.GymRats.uk]

A word of caution from personal experience. After fully insulating our loft with the 270(?)mm Rockwool of the day I inadvertently left the outer wrapping of the last roll just laying on top the the insulation. Shouldn't have caused a problem to my mind but... skip forward a number of years (perhaps 8 or so) and I noticed a patch of ceiling in the kitchen was damp (upsidedown house).

Went into the loft and the small section of plastic wrapping had been acting as a cold surface for vapour to condense on and drip back down through the loft insulation to the ceiling causing a soft patch of plasterboard that had to be cut out and patched up.

Just something to watch out for.

Cheers - Pete

[David]

Could you use off cuts of Kingspan or similar?

As long as there is room to move the blocks to one side.

Cheers

Dave R

[Tim+]

Thanks. I found that company before but couldn?t find an ?order here? link.

Hmmm, maybe if I could find some of that paper fabric used for ?decorating suits? on a roll I could just staple it around an unrolled strip?

Tim

[Tim+]

All gone alas. Think I well and truly missed that boat!

Tim

[Tim+]

Thanks for the warning. As I happens I?ve used a large sheet of polythene to drag it into an awkward spot and I?ve forgotten to remove it afterwards. Will do so now!

Tim

[Tim+]

I suppose but a ?sausage? that I could just roll up would be easier than multiple pieces of Kingspan.

Tim

[Robin]

I have some of the Space Blankets in the loft and the perforations in the foil are petty small. So I'd guess (NB "guess" as in "don't blame me if I'm wrong") you'd get at least as much benefit from sandwiching insulation between 2 lengths of breathable membrane. If you don't need much perhaps wave a tenner in front of a roofer?

[newshound]

How about decorators' dust sheet fabric? Cheap, tough, breathable but should retain any loose fibres quite well.

[Tim+]

That might work. Also thinking about frost protection fleece for plants. That?s pretty cheap and come on long rolls.

Tim

[Andrew]

If you had a 'pathway' to the boiler where the insulation was only toghtly fitting 'celotex' then this is the equivalent of twice the depth of rockwool