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I’m hoping to get a bit ahead of the rush and sort my loft insulation in the coming weeks. House is a mid 90s detached with a truss roof. Total area is about 80m2. There’s 100mm between the joists already so I believe adding 200mm over this will be sufficient?
The question is should I use 200mm at 90 degrees or should I do 2 layers of 100mm? What’s considered best practice?
In terms of what insulation to use, is it all pound for pound much the same? Anywhere particularly good to buy it from?
A 200mm layer will be easier to manage than 2x100
Run it 90 degrees to the joists and make sure if the eaves are the venting for the loft that you don't block them off.
I've just done an extra layer in my loft this weekend, from 200mm up to 300mm.
Gloves, mask, long sleeves and eye protection are really important. Even the 'non-itchy' stuff is horrible
I just picked up some from B&Q.
Existing stuff is so thin and sparse I'm putting 100mm over the top, then 170m at right angles.
Need to sort the loft hatch too, there's a gap when it's shut and it's not insualted at all.
Thing to watch for is the exact width. Some will be 2x600 wide which is ideal for going perpendicular. Some is 1140 (2x570) for going between rafters.
Becomes relevant if you're looking to add loft legs or similar.
When fitting it wrap duct tape around your sleeves and collar, the stuff gets everywhere and itches like hell.
Gloves essential.
Any recommendations for companies? I need to sort ours as existing stuff is 25years old and pretty much useless. Ideally need someone to come and make the loft hatch bigger as well. General builder? Any national or local companies near Burton recommend?
Once you've added the insulation be aware that you may need to up the ventilation in the loft as well to prevent damp/condensation.
Any recommendations for companies? I need to sort ours as existing stuff is 25years old and pretty much useless. Ideally need someone to come and make the loft hatch bigger as well
no need for a builder or company for any of those, your local village handyman is more than capable.
Watch the electric cables, they get hot when under insulation. If it's something bigger like a shower cable then this could be pretty hazardous.
Use an old bread knife to cut it to size, that's what I've seen the prós uses.
I'd go opposite way to the trusses to maximise coverage.
Make sure any downlighters are fire rated too.
I m planning it too, good tip 're duct tape.
You can buy covers for downlighters to maintain a gap between the fitting and the insulation.
https://www.wickes.co.uk/Loftleg-Loft-Lid-Downlight-Protector-Hood/p/148851
Came on here to post those downlighter covers.
Just bought 4 to go with the 6 extra rolls of 170mm insulation in putting in our loft this weekend. Got some 50mm celotex hard insulation for the walkways too, will put 6mm ply above that
Aren't downlighter covers now redundant {if you have LEDs installed}.
Mine give off negligible heat.
Aren’t downlighter covers now redundant
Isn't there job to retain the fire/smoke barrier between floors anyway......well according to those pesky building regs anyway.
Ahh, OK.
The only thing I can say in response is that glass insulation doesn't burn anyway, so maybe it's ok to put 30cm of it on top of the downlights - would it do mostly the same job?
Use an old bread knife to cut it to size, that’s what I’ve seen the prós uses.`
An electric carving knife works much better, doubles for cutting foam too.
Something I found useful is that decent batten lights are quite cheap these days, so if you've just got the one crappy light in your loft stick some better lights in; faffing about in the eaves is sooooo much easier if you can actually see what you're doing and not losing torches under the insulation all the time.
I used knauf rock wool from wickes. It comes with perforations to make it easy to cut to the relevant widths. Much faster to lay one layer than 2. Get a white coverall, invest in a decent mask and goggles as you end up in some pretty tight spaces. A litter picker / grabber is also really useful for lifting it in to the tighter spots. Box cutter and wallpaper scissors were the best for cutting, box cutter probably better. Get a couple of decent boards to bridge the joists for working on and a headtorch. There was loads of crap left up there from the old roof, lots of old black plaster dust / mortar which I went to the effort of cleaning up and so glad I did.
As above, lay it across the joints for best coverage. However, this does make it harder to cross the loft on the joists to access stuff like your TV aerial, water tank etc, so you could plan a central catwalk (ply on loft legs) I just used to feel about to find the joist and then walk across but it does start to break down the insulation depth if you go up there repeatedly.
Check if they are still doing grants, I got mine done for free when I realised it was going to be quite expensive to insulate the larger than average area of a 3 bed bungalow.
You can buy loft hatch kits with a wooden ladder and door/frame from the usual DIY places, as long as you can use a tape measure, screwdriver and a saw and some caulk, I'm sure the average diyer could fit it without a handiman.
I've just topped up the insulation in our loft over the weekend. There was already some existing insulation so I used 170mm Knauf Eco Roll. I found it was cheaper in B&Q than Wickes at £24 per roll.
I laid it at 90 degrees to the existing insulation and used a small plank of wood underneath to help jiggle it into position in hard to reach areas. I also installed so LoftLeg XL loft legs and a few boards for storage, so I used those boards as crawler boards to span the joists whilst laying the insulation.
The tip about taping cuffs is brilliant. I was wearing goggles, dust mask, overalls and gloves but was still itchy and needed a shower as soon as I was done.
Aren’t downlighter covers now redundant {if you have LEDs installed}.
Mine give off negligible heat.
Depends on the LED. Mine had symbols on top indicating insulation was not to be laid on top.
I presume the LED light cables are ok under insulation. From what I can tell 1mm is ok for 8a under insulation (16a in the air). The fuse is 3a so I can't see a situation where they'd go over 8a. The lights are 6w each so prob drawing 0.1a total most of the time.
anyone have any tips for fitting insulation over a hatch which has a fold up ladder attached. I'm thinking it can't be done from inside the loft.
common way is to box in the hatch from above and create a secondary hatch into the attic above the ladder .
ill end up there eventually but for now i have a 40mm rated and sealed solid insolation hatch on the bottom. of the ladder which should be a marked improvement on the old 12mm ply i had doing the job.
Once you’ve added the insulation be aware that you may need to up the ventilation in the loft as well to prevent damp/condensation.
Ignore this ☝️ At your peril.
Upping insulation, and particularly pushing it into the eaves can massively increase household damp/moisture/condensation etc.
We moved into an old cottage and we noticed over the space of 4 years the moisture levels were gradually rising. In winter our windows would stream like a waterfall with large pools of water on the sills every morning. The carpets, bedding, furniture and curtains all felt damp. The moisture meter was showing 87%
In the process of fitting a Nuaire PIV I noticed the loft insulation was very deep, and when I pushed my hand arm deep inside my hand came out wet.
Basically we were suffering interstitial damp caused by the loft insulation being so deep; as the warm air travelled through the ceiling, through the insulation, it was gradually condensing and trapping within the insulation. This is because it was too deep to allow the warm air evaporation into the loft. Furthermore, the eaves had been stuffed full of insulation meaning the house didn’t “breathe”. All of the woodwork, joists etc. we’re wet and some were beginning to rot.
I’ve now removed 36 large bin bags of insulation, leaving just about 9” between each joist. It’s all the old stuff that had been covered over, and way past it’s best. Totally replacing this with a quality product is top of my “jobs to do” list.
Houses are designed to “breathe”; they need ventilation and movement of air, so if you’re adding insulation just remember that there is such a thing as too much. Ignoring this can be incredibly expensive in the long run.
Extra tip for the shower post work, make it a cold one. The hot water will open the pores and make it harder to rinse the unseen dust off your skin.
Flip side to the above. Ive stuffed insulation into the gaps in my loft and the moisture has dropped from 75+% to <60% while we still get windows the house is a lot better overall.
As for the light covers? My LEDs downlighters are 10W and while it is arguable that they would be safe I paid £18 for the covers just for peace of mind. Even 10W over time generates a decent bit of heat.
Flip side to the above. Ive stuffed insulation into the gaps in my loft
Which gaps though.....
That's a good point re air gaps. I was insulating the pitched roof section of our dormer bungalow, so the area above the flat roof sections. I did maintain the existing air gap by insulating up to the purlin but not over the top of it, as that's where the existing insulation was.
It's pretty draughty up there and everything was dry, so i'm hoping the ventilation is adequate. I'll pop up periodically over winter to keep an eye on moisture levels.