Loft Insulation help

[Mark18PLL]

I am looking to re insulate our loft and re board, it is used for storage and we also have some computer equipment running. It has been boarded in parts by the previous owner but electricians and plumbers have been in and hacked away at parts, I am also not sure if the boarded parts have any insulation under them and if it is it will be squashed.

The joists are 100mm so im not going to get a decent thickness of insulation in and be able to leave an air gap and board over, I had thought about laying some 4 x 2 but it will only give me another 50mm. I am also thinking of running foil insulation down the rafters but these will have a decent gap behind, the eves are also vented so airflow is pretty good.

Any ideas would be grateful, I don't want to do it cheap but at the same time can't spend a fortune.

Cheers Mark

 

[seanf]

I"m considering StoreFloor from LoftZone for ours, either a section or the whole loft. Interested to hear the replies to this

Sean

 

[MARK.B.]

Ask your local council if they are running a warm home scheme, I have two lofts(smaller one over the extension) that have just been done and they now have approx 270mm of insulation in them,all for the princely sum of £99.00.

 

[Chris70]

Mark18PLL:

Hi Mark! When you say "I am also thinking of running foil insulation down the rafters", have you considered TLX. Here's a link https://tlxinsulation.co.uk/

It's good, but it's expensive. The economist John Ruskin (08.02.1819~20.01.1900) said:

It's unwise to pay too much, but it's worse to pay too little. When you pay too much, you lose a little money - that's all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do. ​

 

[Seascaper]

I am looking to re insulate our loft and re board, it is used for storage and we also have some computer equipment running. It has been boarded in parts by the previous owner but electricians and plumbers have been in and hacked away at parts, I am also not sure if the boarded parts have any insulation under them and if it is it will be squashed.

The joists are 100mm so im not going to get a decent thickness of insulation in and be able to leave an air gap and board over, I had thought about laying some 4 x 2 but it will only give me another 50mm. I am also thinking of running foil insulation down the rafters but these will have a decent gap behind, the eves are also vented so airflow is pretty good.

Any ideas would be grateful, I don't want to do it cheap but at the same time can't spend a fortune.

Cheers Mark

Hello,
Have you thought of adding Celotex. It sounds like you are going to have to lift the floorboards. You could add depth to your rafters and then cut and lay Celotex between the raised rafters, then relay the flooring. It is important to keep a good airflow if this space is unheated otherwise condensation can form and then mould.
Regards

 

[Doug71]

I recently upgraded the loft insulation for a friend.

I used 100mm insulation between the joist then 170mm on top of it running perpendicular which I think brings it to the recommended level.

I made a platform using some plastic legs from B&Q and boarded it with their loft boards, it was surprisingly sturdy. The legs give the required airflow over the insulation.

https://www.diy.com/departments/diall-loft-storage-stilt-pack-of-12/3663602538240_BQ.prd

 

[MikeH]

Have you looked at loft lifters like B&Q sell? They are black plastic stilts that attach to the rafters, with a circular top then you put loft boards on top, lifts those loft boards about 200mm up so you can have insulation underneath. I used some in a bit of the loft for storage so I can have a decent amount of insulation under them. They are pretty easy to fit and once the loft boards are on they are rock solid. Not too expensive either.

 

[MikeH]

Hah, Doug 71 was typing the same thing as me at the same time Great minds and all that!

 

[treeturner123]

Mark18PLL:

Hi Mark! When you say "I am also thinking of running foil insulation down the rafters", have you considered TLX. Here's a link https://tlxinsulation.co.uk/

It's good, but it's expensive. The economist John Ruskin (08.02.1819~20.01.1900) said:

It's unwise to pay too much, but it's worse to pay too little. When you pay too much, you lose a little money - that's all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do. ​

Quite right Mark

See my tag line below!

Phil

 

[trvlr]

Perhaps solid insulation (kingsman/celotex etc.) between loft joists would work. I think 50-75mm more than equates to the rock/mineral wool roll stuff (knaups etc.) and still leaves an air space between loft boards and joists. Not cheap and a bit more involved in cutting/installing it. If using this material, wear a good dust mask when cutting it.

 

[Terrytpot]

I am looking to re insulate our loft and re board, it is used for storage and we also have some computer equipment running. It has been boarded in parts by the previous owner but electricians and plumbers have been in and hacked away at parts, I am also not sure if the boarded parts have any insulation under them and if it is it will be squashed.

The joists are 100mm so im not going to get a decent thickness of insulation in and be able to leave an air gap and board over, I had thought about laying some 4 x 2 but it will only give me another 50mm. I am also thinking of running foil insulation down the rafters but these will have a decent gap behind, the eves are also vented so airflow is pretty good.

Any ideas would be grateful, I don't want to do it cheap but at the same time can't spend a fortune.

Cheers Mark

We recently moved from a newish semi to a detached bungalow and one of the first “issues” we needed to get resolved was the inadequate loft insulation that had been occupied by small furry beasts.. The residence portion is roughly 125 square meters and we removed all of it..any that was in good condition was bagged and saved to be used above the uninsulated garage. We then laid 100mm of knauff itchy coo between the joists and topped it off with 200mm of their stuff at right angles and for a fair chunk we’re still in the process of screwing down the loft legs and over boarding with 18mm t&g board @2400x600 (was fun getting them up through the hatch) which along with a dozen of those covers for keeping the insulation away from the kitchen downlights and quite a bit of ppe has cost us roughly £800 .
It’s a job that had to be done and one I will be extremely glad to have behind me although we could probably have managed fine without boarding a chunk of it for storage but seemed a bit silly to lose the option as it’s really not a task you want to attack more than once.

 

[Dave Moore]

Perhaps solid insulation (kingsman/celotex etc.) between loft joists would work. I think 50-75mm more than equates to the rock/mineral wool roll stuff (knaups etc.) and still leaves an air space between loft boards and joists. Not cheap and a bit more involved in cutting/installing it. If using this material, wear a good dust mask when cutting it.

The only problem with celotex is ensuring the fit is tight. Latest regs require Gapotape or similar which is very expensive. I just fitted out my step sons new bedroom extension and even although it’s good you still need good layout of the trusses or else you are making tapered cuts to allow for fit. Gapotape takes up 8mm gaps but cables also make for required adjustments. The videos on youtube make it look simple. Lol.

 

[XTiffy]

I am looking to re insulate our loft and re board, it is used for storage and we also have some computer equipment running. It has been boarded in parts by the previous owner but electricians and plumbers have been in and hacked away at parts, I am also not sure if the boarded parts have any insulation under them and if it is it will be squashed.

The joists are 100mm so im not going to get a decent thickness of insulation in and be able to leave an air gap and board over, I had thought about laying some 4 x 2 but it will only give me another 50mm. I am also thinking of running foil insulation down the rafters but these will have a decent gap behind, the eves are also vented so airflow is pretty good.

Any ideas would be grateful, I don't want to do it cheap but at the same time can't spend a fortune.

Cheers Mark

The plastic leg supports seem to be the most economical route. When building a house (2004) Bldg.Regs called for 10" of Rockwall, so I used 4 inch then fitted 6x2s cross ways to enable a further 6" on top. I then fully boarded the loft. My present house(10yrs ago) was insulated with Sheep's wool, which turned out to be a wonderful haven for moths and destroyed hundreds of £s of clothing. All insulation had to be removed and ditched. I would not go down the celotex route as it is not imune to fire (Grenfel disaster was Kingspan insulation) and must be fitted with great accuracy. Rockwall is non-flamable . I have used the multi-foil insulation (walls using battens), at least it is clean with no dust!