View Full Version : Loft insulation

22nd Nov 2013, 22:40
When I moved into my property I boarded the loft with a layer of the original insulation below the boards. Said insulation is probably about 15 years old.

What with all this government grant malarkey I could have a modern proper layer of insulation but the chappie who came to do the survey etc said it would have to lay on top of the boards.

I have quite a lot of stuff which I store up there and this would leave minimal space for storing same (yes I know I could dispose of at least half of the stuff but even then there would still be quite a lot).

Other than lifting the boarding, laying new insulation and raising the boards by placing cross supports on the original beams does anyone know of another fix which would provide a comparable level of modern insulation?

Thanks for any help

Gertrude the Wombat
22nd Nov 2013, 22:59
One hears rumours that there does actually exist some rather more expensive insulating material that will do a decent job just filling the space between the existing beams. One has not, however, heard any rumours that this rather more exensive kit is available via any of the grant schemes.

There are two main reasons why take-up of the grant schemes is somewhat low - one, as you observe, is the potential for losing storage space, and the other is simply that people can't be bothered to move the junk around to allow the insulation to be fitted.

22nd Nov 2013, 23:02
I'm about to do the same. I've gone for the glass fibre rolls for all the hard to reach places. For the storage area I'm looking at ply wood with a thick layer of polystyrene glued to the underneath. They have a tongue and grove design. And seem pretty strong.

22nd Nov 2013, 23:39
I was told that to qualify for the government scheme, 75% of the loft area had to be available to be insulated. We took this as an opportunity to clear out some junk.

Result was that the loft now has a much better layer of insulation and it didn't cost us a penny. It's a big bungalow so the area to be covered is about twice that of a normal house. Not often I could say that I've taken the time to listen to someone who came knocking on my front door to offer me something that sounded too good to be true.

But I finally have got something for nothing out of our county council - apart from a bit of overdue self help to clear the loft space. :ok:

23rd Nov 2013, 00:34
Would something like this work?

OPTIMAŽ Blow-in Insulation System - Blowing Insulation - Fiber Glass Insulation - Insulation - CertainTeed (http://www.certainteed.com/products/insulation/fiber-glass-insulation/317369)

23rd Nov 2013, 01:42
It would be worth your while looking at the general level of insulation around the rest of the house first. There's bugger all point insulating the roof more if your doors or walls leak like a sieve.
Draught-excluding is the first priority, and good curtains/heat-insulating blinds are worth looking at too. Do you have insulation in your cavity walls?
Failing that, use a single layer of rigid foam board and relay your loft 'flooring' on top of that. You may not need supports through the foam boards if your flooring and stored items aren't very heavy. If you can lay the foam boards cross-wise to the insulation/joists you can avoid the thermal bridging effect of the wooden ceiling joists.
High R-factor (low U-factor) insulation between the joists doesn't make much difference as the wooden ceiling joists act as a heat bypass. It's a continuous layer on top of the joists that makes the real difference.

23rd Nov 2013, 07:45
I have quite a lot of stuff which I store up there....

Other than lifting the boarding, laying new insulation and raising the boards by placing cross supports on the original beams does anyone know of another fix which would provide a comparable level of modern insulation?

You want to be sure that the loft floor joists are strong enough to take any significant weight of stored items and extra weight from any cross joists and boarding. Unless they are around 230mm thick or more, like your first floor joists, most roof floor joists are not load bearing and are just to complete the triangle with the rafters of the roof structure to stop the roof pushing the walls out. This particularly applies to maunfactured roof trusses, which are the minimum thickness to take the actual and imposed loads of the tiles etc and are not designed to have any extra weight placed on them with storage etc.

G&T ice n slice
23rd Nov 2013, 08:48
have a look at

the insulation goes between & below the spars - drops the headroom a bit.

you need to ensure there is airflow above the insulation to keep the spars healthy though, so may mean a "false ceiling" below the centreboard. it all depends on exactly how the roof is constructed

23rd Nov 2013, 09:28
What Cragman said.

If you temporarily clear it all out, then get it done under the free scheme, then get a few of those panels, clear the central area of the new insulation and fit the panels. The removed new stuff can be used to double-up around the perimeter.

23rd Nov 2013, 12:48
The only thing that would really help insulate my solid-walled house is exterior cladding.

Never a hint of help to have that installed of course.

23rd Nov 2013, 12:52
Free External Wall Insulation ECO Grants Now Available (http://www.freeinsulation.co.uk/solid-wall-insulation/external-wall/index.html)

23rd Nov 2013, 12:53
Fitting Loft Legs - YouTube

23rd Nov 2013, 13:21
Since there is no attic above our very old-fashioned plaster-tile ceilings, we had a builder put up a lattice work of laths onto which 24-ply insulation was fastened (this compresses down to 3mm thick and was originally devloped by a contractor to ESA), plasterboard on that, plastered and painted. At the same time had new wiring put up and new lighting. Came to about 1200 pounds sterling a room. But of that the painting would have had to be done anyway on the old ceiling and Mrs OFSO wanted new lighting, and who can say no to a wife's whims ?

It's been hard to check on energy savings directly since this summer was not atrociously hot and the cold weather didn't arrive until mid-November, but looks like it will be at least 15%, maybe 20% over last year.

23rd Nov 2013, 13:24
Vulcanised - you can fit it on the inside if you don't mind losing 3 or 4 inches. I have done it in our new kitchen and the temperature difference is noticeable.

75mm polyurethane foam and 12.5 mm plasterboard, skimmed.

23rd Nov 2013, 15:23
Unfortunately not a practical option inside = especially on the North facing wall which is the largest. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/cool.gif

23rd Nov 2013, 15:37
Near neighbours, whose house lies within the floodplain and has been regularly 'submerged' to a depth of a metre, had the building 'tanked'. The outside walls were coated in bitumen and then a further wall was built to a height of a couple of metres. All drain services were then re-routed to prevent backflow, and finally the one remaining doorway is fitted with a barrier that can be erected to keep the river out.

The major problem is that it isn't possible to gain access once the flood begins, so they have to evacuate or remain marooned until the flood subsides.

24th Nov 2013, 02:14
Remember removing all the old insulation about 10-12 years ago after buying the house, V hot summer with mate and I suited fully in disposable protective gear (like the cop suits at murders), gloves and facemask. Stuff was black and had 10 bin bags full which hit the skip. Face mask breathers were a must as both of them were black from dust and these were expensive ones acquired for a beer from a friend in the business.

Stupid fibres still got everywhere and arms around cuffs itched for days. However we rewired the place completely and new insulation was a dream to put down.

Would clean and remove the old crap, dejunk and then get new relaid at no expense.

Loose rivets
24th Nov 2013, 06:06
1960 spec house had 16" spaced, really 4 X 2, everywhere. Boarded it with floor quality chip. Set about making the second attic higher with steel RSJs carried by three of us up three ladders. 17' span I beam. It was a test.

Supported the purlings on the beams and local joists had overhanging 1/4" thick steel washers set into the I beams to lift the ceilings via coach bolts.

Floored the lot in chip.

Marked out the bays and listed the hundreds of items stored aloft. (ho ho)

Sat back and farted contentedly.

Sold house.

Took most of the stuff down the village dump and auctioned off the rest for tuppence.

Kicked self up jacksie for next ten years.

Funnily enough, my host this last summer had her loft insulated with 170mm stuff. The other pal that did the job put in a raised walkway to put stuff. I think it's a Wimpy home or some such. Nice 4 bed detached, but nothing like my 60s build. I'd be hesitant to put my 200 lbs on that ceiling structure - before or after the work.