This wills seem a silly question to those of you who probably know but we had our loft insulated to about 6 inches higher than the rafter with that roll stuff. If i was to get it boarded would that mean that as the thermal wadding became depressed it would also become less efficient/effective?
Janet
Yup, it would become less effective. Do you want storage or insulation? Thats the choice.
You could insulate under the roof rather than over the ceiling. My loft storage has the roof insulated precisely because the above-ceiling insulation was compressed under some chipboard.
"Bruce" wrote
OR use more thermally efficient insulation between the joists below the boards and put carpet on top of the boards - probably get you most of the way to equalling the thicker stuff elsewhere.
Phil
Compressing it makes it less effective.
Boarding over it makes it more effective, especially in a high wind situation.
In fact its probably true to say that traditional loft inuslation is next to useless if you have a well vented roof, and the wind is blowing hard.
Ive got 7" up there, and the difference when I boarded it up was remarkable.
But for best effect, board it without compressing. Just lay extra joists at right angles to existing.
People worry far too much. The difference between an uninsulated loft and one with 4" between the rafters is huge (lots of pounds per year) - all agree on that. The difference between a boarded loft with insulation (uncompressed) between the boarding and ceiling and one with an extra 6" laid on top and no boards is pretty minimal (pennies per year) in the grand scheme of things.
funny this should come up, I was pondering this just last night.
Our loft is pretty much boarded out but I'd like to increase the insulation up there. Don't want to take up the boarding really - and we use it for a fair bit of storage...storage of some stuff that I'd prefer not to have in the loft suffering extremes of temp :-(
Hence I was pondering insulating the roof somehow.
Not looking to spend a fortune on this, but what are the options for making the roof space a bit cooler in the summer and a bit warmer in the winter? I'm not looking to turn this into a usable room - just make it a little more stable in temp. Currently roof is just slate - no felt or anything just bare slates so we get a fair amount of dirt/dust in there as well. Cutting down on that would be a bonus.
Of course, if it was a bit warmer up there I could start by grand plan of the uber trainset in the loft (ha, as if that's ever going to happen!)
Anyone else done this and not had the roof rot away etc?
Darren
"Janet Tweedy" wrote
Another option is to add some elevated storage. It will depend on the roof construction how easy this is. If it is modern "W" truss, you can put batons across fixed to the "vertical?" timbers, then lay boards across those for storage. Not suitable for really heavy stuff, but keeps the joist area clear for thicker insulation. All you need then is a single walkway to provide access.
Phil
Yup, rot is the usual concern, however in your case its quite easy by the sounds of it, since you probably have ventilation through the slates with no sarking to block it.
So you can cut rigid insulation board to fit between the rafters, and then possibly add a second thinner layer over (well under, IFYSWIM) the lot. Finish with plasterboard if you want to be posh, or just hardboard painted white for a cheap smooth surface.
If you cut some blocks to fix to the sides of the rafters you can set the max depth of the insulation and stop it pushing back against the slates. Aim to leave about 50mm of breathing space behind the slates.
There is a bit more info on how I did mine here:
I used 50mm Rockwool slabs between the rafters, which left a 50mm gap between it and the slates. There is now virtually no difference between summer and winter temps up there, and no adverse effects after 10 years or so. 25mm Celotex would probably do the same job, and that has a built in vapour barrier, but 8x4 is too big for my loft hatch.
In article , TheScullster writes
Don't think it's a w Phil, it is a 1935 detached house with pine rafter etc. but not much head room most of the height in the middle of the roof. Might board a few bits just so i can store some boxes up there. Tiny roof hatch so it will have to be cut small enough to get the planks up there. The idea of insulating the inside of the rafter sounds good as well as our house is quite cold in the centre up the stairwell. (We ought to have bitten the bullet and upped our central heating system from gravity feed I guess)
Janet
"Janet Tweedy" wrote
Is the hatch near a wall? If so some cheap brackets and planks (which should fit thro the hatch) would provide useful storage but keep the joist area clear for insulation.
Phil
Cut rafter gap width sections ought to go through most hatches though.
Yep, ventilation isn't a problem in our loft :)
I was thinking hardboard - this doesn't have to be particularly pretty.
than the local merchants - anyone in particular? Seems that a couple of places sell seconds - I assume this would be cheaper still (cheap == good for this project!)
Cheers,
Darren
ACPO Wholesale in Benfleet. Typically doing 50mm PIR foil faced seconds at £10 per 8x4' sheet equivalent[1] (they may supply bigger sheets like
12x4'). Drop me an email if you want the number and I will find it. [1] at least that was the price when I ordered a van load for doing my workshop toward the end of last year.HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.