Non-motoring > Loft Insulation Advice Sought Green Issues
Thread Author: zippy Replies: 25

 Loft Insulation Advice Sought - zippy
I need to add loft insultation. The current stuff must have been added when the house was built in the '80s and it's about the thickness of two sheets of loo roll!

The rafters are quite thin and can't support a lot of weight.

Was thinking about fiberglass type or whatever the current modern equivalent is unless anyone can advise anything better / more cost effective.

I am shocked at the price. Last time I did this it was £2 a roll now it's £30!

Also I have about 40 led ceiling lights (well some are old style so will need replacing). Are caps required for them in the loft or is it just marketing - eg www.wickes.co.uk/LoftLeg-Loft-Lid-Downlight-Protector-Hood/p/148851?

Thanks
 Loft Insulation Advice Sought - Kevin
Before you get the credit card out check to see if energy companies (or your local council) are still doing free/subsidised insulation. British Gas topped up my loft insulation to about 400mm years ago. Gratis.

They were also doing free cavity wall insulation if it was needed.
 Loft Insulation Advice Sought - zippy
Thanks Kevin, I did look. House needs to have an "E" rating for energy efficiency and ours is "D" unfortunately. Some schemes are also restricted to council tax bands "D" and below. Ours is "E" annoyingly.
Last edited by: zippy on Wed 13 Nov 24 at 22:35
 Loft Insulation Advice Sought - bathtub tom
>> ours is "D" unfortunately.
>>Ours is "E" annoyingly.

?
 Loft Insulation Advice Sought - zippy
>> >> ours is "D" unfortunately.
>> >>Ours is "E" annoyingly.
>>
>> ?
>>

"D" refers to the energy efficiency of the house. It needs to be "E" or worse to get a grant.

"E" refers to council tax. It needs to be "A" to "D" to get a grant. Crazy because bands don't relate to income.
 Loft Insulation Advice Sought - Kevin
No restrictions at all when they did ours. They just checked that the existing insulation was below latest recommended thickness. Even got them to do the loftspace above the garage.

Wall cavities were checked with a boroscope to make sure the builders had done their job properly.
 Loft Insulation Advice Sought - zippy
What energy co is that? Could change to them if they still offer it.
 Loft Insulation Advice Sought - Kevin
It was done by a British Gas contractor but I wasn't even a customer. I'd switched suppliers about a year earlier.

It's a while ago now so recall is a bit vague but I think we'd had a letter from British Gas saying that they were supplying extra insulation as part of a Govt. scheme and if you had less than a certain depth of loft insulation they'd top it up for free. I contacted them and they came around, checked loft and installed it on the same day. Only requirement was that you'd cleared any junk out of the loft.
I had about 100mm between rafters and they added another layer perpendicular to the old stuff that appears to be about 300mm thick so ~400mm in total.
 Loft Insulation Advice Sought - Zero

>> Also I have about 40 led ceiling lights (well some are old style so will
>> need replacing). Are caps required for them in the loft or is it just marketing
>> - eg www.wickes.co.uk/LoftLeg-Loft-Lid-Downlight-Protector-Hood/p/148851?
>>
>> Thanks

They were required when ceiling lights were incandescent, for heat dissipation reasons. Still advisable to use them for access reasons. Some higher power leds still need to disipate heat.
 Loft Insulation Advice Sought - smokie
The electrician currently (haha) working on my kitchen won't fit non-fire rated ones. I think cos of regs, not personal preference.
Last edited by: smokie on Wed 13 Nov 24 at 23:21
 Loft Insulation Advice Sought - Zero
To bounce this in an unrelated direction.

In the bathroom we have 4 MR16 Dichroic ball type 12v lights in the ceiling. Yesterday 3 of them went out, fiddling with one of the bulbs they all came on. Hour later, same three out again. The "this is dangerously flakey". flag is hoisted uo the flagpole.

So quick trip to the Amazon mall, sees a pack of 6 LED Downlights Ultra Slim 7W LED Recessed Ceiling Lights arrive and a wago connector box.


Up into the loft crawl space, the old (deffo not IP44 rated for bathrooms) come out (one falls to pieces), out comes the wiring back to the pull switch, out goes the 1970's 12v transformer. The wiring was laughable, a mix of ring main cable, lighting cable and numerous chocbloc connectors,

Anyways, the delight of the morning was the Wago connection box. My first time using one in anger, what an absolutely fantastic piece of design.


Set the lights to warm while over the bath, and cool bright white over the sink and loo
Last edited by: Zero on Thu 14 Nov 24 at 13:40
 Loft Insulation Advice Sought - Fullchat
The Wago systems are brilliant.

Your original lights were probably fitted by 'professionals'. Those people we have to employ so as they can sign off the required certification.
 Loft Insulation Advice Sought - zippy
This may be a silly question - apologies in advance....

I have thin joists in the loft with insulation in the gaps. If I top up the insulation, then put loft flooring over, will it be worth adding further insulation over the boarding?

So From top to bottom:

Insulation
Loft flooring
Insulation
Ceiling

Thanks.
 Loft Insulation Advice Sought - tyrednemotional
Probably better to use boarding "legs".

Link below is simply an example which shows the concept. They're widely available and probably better value elsewhere.

tinyurl.com/loftleg1
 Loft Insulation Advice Sought - bathtub tom
Years ago, I topped up my loft insulation to 4" (100mm, the height of the joists) and floored it on top. I couldn't find a definitive answer to how that affected the overall insulation, but surmised that as insulation's all about trapping air, then flooring panels would be doing a similar job. The problem with laying insulation on top of flooring is you effectively make the loft unsuitable for storage or walking on.
 Loft Insulation Advice Sought - sooty123
Depends if you want to store or go in the loft. If not layer up the loft insulation, if you do need access fit loft legs.
 Loft Insulation Advice Sought - Terry
Flooring should not be a problem but you are then left with a cold loft space.

You need to make sure that there is:

- no easy route for moisture inside the house to find its way into the loft where it could condense and rot the rafters (eg: seal any hatch into the loft, and

- ensure that there is a decent airflow in the loft - don't block the eaves or any air vents you may have in the soffits or gable ends.
 Loft Insulation Advice Sought - Manatee
You can get different insulation that does require so much depth to go under the boards. Then just pile the extra insulation around the edges which are unbiased.

I got a large area if mine boarded when we built it (we used attic trusses). The insulation that went under it was the same brown stuff we used between the bedroom floor joists. Unfortunately I can't tell you what that was.

Or raise the flooring on legs so you can get 3/400mm under the boarding.
 Loft Insulation Advice Sought - sherlock47
My loft is split between the old and new sections , New sections with 7x2 (longish spans) and old 5x2. i keep thinking that I should add to the existing insulation which varies from 100mm to 150mm but insulation is augmented by my passion of keeping the old packing boxes from white goods, electronics etc containing the polystyrene formers. In my head this limits the circulation of air thereby significantly reducing heat loss. There appears to be significant draughts to reduce the risk condensation, and the heat loss keeps the lightly insulated tanks ice free in the winter.

Would seem a considerable expense to reduce heating bills - not sure whether worth it, particularly since number of future years must be limited. Any experience of reduced EPC resulting in reduced selling price or use as as a negotiating (downwards) factor when the time comes?

4 Bed detached annual consumption
2022 gas 15849 kWh elect 3609 kWh
2023 gas 15912kWh elect 3750kWh
2024 gas ~17000kWh elect ~3500kWh
 Loft Insulation Advice Sought - zippy
>>Would seem a considerable expense to reduce heating bills

Yes it is quite an expense, but to be honest, it's more about comfort as well.

I go to relatives' and friends' houses and they are warm and toasty with heating bills about the same as our "fridge".

It's a 1980s house, though poorly insulated. I will be insulating, draught excluding and replacing double glazing over the next few years (currently the windows are wood, some of which are beyond repair and the double glazing gap is miniscule - I guess under 5 mm).
 Loft Insulation Advice Sought - Zero

>> It's a 1980s house, though poorly insulated. I will be insulating, draught excluding and replacing
>> double glazing over the next few years (currently the windows are wood, some of which
>> are beyond repair and the double glazing gap is miniscule - I guess under 5
>> mm).

In your boots, I would be doing this first, I suspect chucking more insulation in your loft is approaching the law of diminishing returns.
 Loft Insulation Advice Sought - maltrap
Slight thread drift, is triple glazing worth the extra cost?
 Loft Insulation Advice Sought - Zero
>> Slight thread drift, is triple glazing worth the extra cost?

Depends. On your window sq footage, and the age and efficiency of your existing double glazed windows. If your current double glazing is fairly recent, then no you probably wont recover the replacement cost of triple glazing in a reasonable timescale. If you are changing windows anyway, then yes its worth the extra.
 Loft Insulation Advice Sought - James Loveless
"It's a 1980s house, though poorly insulated. I will be insulating, draught excluding and replacing double glazing over the next few years (currently the windows are wood, some of which are beyond repair and the double glazing gap is miniscule - I guess under 5 mm)."

"In your boots, I would be doing this first, I suspect chucking more insulation in your loft is approaching the law of diminishing returns."

Agree entirely. A few years ago we replaced our wood-framed narrow-gap draughty double glazing with modern stuff. Don't forget glass is now coated with high-tech stuff to help retain heat, as well as the gap between the glass being larger and draught-proofing much better. (Bonus - you can clean the windows from the inside.)

The improvement in warmth was very noticeable.
Last edited by: James Loveless on Tue 26 Nov 24 at 23:19
 Loft Insulation Advice Sought - Bromptonaut
>> In your boots, I would be doing this first, I suspect chucking more insulation in
>> your loft is approaching the law of diminishing returns.

Ditto.

Our old house was seventies built and when we moved in still has single glazing and wooden frames some of which were going rotten. Not good seals and draughty.

Big single glazed window at the rear of the lounge/diner. You could literally feel the cold air flow down that window and, in spite of a heavy curtain, spill across the floor.

UPVC double glazing transformed it. However inhibiting 'natural' ventilation set us up for mould in corners of rooms and behind furniture on outside walls.

If you cannot afford to reglaze in one hit it's worth looking at secondary glazing. Balloons up chimneys that are not in use are another quick fix.
 Loft Insulation Advice Sought - sooty123
There's a gov site you can put on your current insulation, your proposed and current energy price it then works out the payback.
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