Loft insulation - Kingspan?

You might be better off lifting the boards above the ceiling and sticking the Kingsan under there - inch for inch, it's much more efficient and insulator than Rockwool.

I'm assuming that your roof space is designed to be well ventilated; if you leave it that way and put Kingspan between the rafters then much of the benefit of that will be lost because the roof space is (intentionally) so draughty. If you were to try and combat that by closing off all the ventilation up there (if that's feasible), you could run the risk of getting condensation and damp up there, followed by rot.

Not saying it can't be done (and it might even be the best way for you), as plenty of people make their roof spaces into habitable rooms; I'm just pointing out that the whole process of curing your heat loss it's quite as simple as slapping up Kingspan between the rafters...

David

Good point, thanks David.

It's easy to tell. Buy yourself an infra-red thermometer, and measure the temperature of the upstairs ceiling all over. Colder areas are where you are losing more heat. See if that corresponds to the boarded area in the loft. In my case, the loft hatch was the coldest area.

I think I saw infra-red thermometers on sale in Maplins yesterday for around £20.

You can continue this exercise across the inside surfaces of all the outside walls/doors/windows, to see where you're losing heat. Alternatively, check the outside surfaces of all the outside walls/doors/windows for warm spots, for the same result.

Thanks Andrew, that's a brilliant idea - and an excuse to get myself a new toy as well :o)

Or even 7 quid off ebay! Probably not the most robust or reliable model, but I bought one of these and it works - hard to beat for the occasional or one-off use:

David

Do you use the loft for storage, yourself? If not, your easiest solution would seem to be to lay extra insulation on the loft floor, including on top of the boards. I think the current standard is 300mm, but someone else might know better.

If you do want to use it for storage, you could lift the boards and install Kingspan or Celotex before replacing them.

Insulating between the rafters is a bigger job, and a different kettle of onions in that you are aiming to create a warm, rather than a cold loft space. You need to ensure proper ventilation behind the insulation, the nature of which depends on the kind of roofing felt you have - breathable or impervious. If you want to go down that route, then plenty of people here can advise, but I suggest you'll be better off bringing the insulation on the loft floor up to scratch.

Cheers Richard

Thanks Richard. I'm going to take your advice (and Lobster earlier also suggested it) and lift the boards, put the Kingspan in there and refit the boards again - along with Andrew's suggestion of buying myself an infrared thermometer :o)

Thanks all,

Dave

I'll just add to this, it's the sort of toy you'll take out time and time again because you have it, and it can give you an instant gadget gratification every time :-)

I know i've done the same several times over the last year, and daily over the last few days to get an idea where the cost spots are...

In ours, the only real cold spots now seem to be where the ceilings meet the outside walls (14C as I type) - internal walls are typically at 20-22C, and the outside walls are typically 17-18C (although one unused room with the heating off and the door shut is at 11.9C)

I've just bought a new one from Chinavision for around 15 quid and it's vastly more precise & repeatable than a 2-3 year old 30 quid model from Maplins ever was (which wasn't much). Seems the newer tech has improved.

That's interesting. I've bought a number of newer ones for other people, but I still have my old maplin one, which must be over

NNNOOOOOOOOOOO!!!! Well OK, if you insist on a pukka DIY job.

If you're a bodger like me you'll buy some rigid foil-coated insulation board (Kingspan? I think mine's called Celotex) and JUST LAY IT ON THE BOARDS!! We store loads of stuff in our loft, which is boarded like yours; I don't walk around in it much, and the board is perfectly capable of taking my weight (with the floorboards underneath it of course) without deforming. None of the items stored (including heavy boxes) would affect the insulation board.

I came to this bodging conclusion after trying to push the trimmed board underneath the floorboards between the ceiling joists (my brilliant Plan A): impossible, thanks to crosswise timbers, the tops of partition walls, etc. BTW it was also impossible to lift the boards: they're genuine T&G floorboards, installed by a genuine joiner sometime in the

Plan B hit me like one of those giant lightbulbs, and saved me days of work.

Cheers John

That would work. Depends how much headroom you want to lose. 50mm would make a significant difference in conjunction with the stuff that's already under the boards, but the more the better. Chuck the boards over the top and bung a few long screws through to stop it moving about (making sure not to hit any pipes or electics under the boards beneath). You could tape the joins to make it continuous. Kingspan is better to walk about on than Celotex (though more expensive) because the foil stuff is stronger.

There you go, lots of options ;-)

Cheers Richard

Lift the boards. Put rockwool between the boards. Put over "all" the joists with rigid foam insulation. Then put the boards over the insulation and use long screws through the boards, foam and into the joists. Then all the cold bridges are eliminated. Board up to the boiler. Your gas bills will drop.

Love it John!!! :o)

Seeing as it is made by Maplin, will it actually last a season without falling apart?

-- JJ

Think I'd still clad it with something even if it's only hardboard. Drop a box or have a point load from something and you will damage the foam which will then hace an edge which will catch on things and damage the foam etc.

Maplin don't *make* anything. They *market* electronic items that are made by other companies, mainly in the far east.

But you're right in that they don't have the greatest reputation for selling quality items.

Bruce wibbled on Monday 04 January 2010 23:57

They used to be better. I still have Precision Gold multimeter, over 25 years old, side push button range select, excellent ranges (upto 20A DC current) and it was exceedingly well built for a lesser name. Dunno what the current stuff is like though...

I've just ordered one. £7 inc p&p.

mark