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Roof Insultation
Anonymous user 15/03/2024 - 2.53 PM
Hello I have recently been reviewing the insulation in my house & the previous owners have put mineral wool insulation between the roof rafters. There is also no felt on the underside of the tiles (it is a 1940's property so not unusual). The mineral wool insulation feels damp, is this OK - should it be there? Would it be better to have this removed & have a breathable membrane installed? I should also say that the roof floor is insulated with mineral wool & it is boarded. Thank you! Susan
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4 Answers
Oaklands joinery services
Rating: 5 out of 5
The felt will be doing more harm than good susan.. the warmth from house will warm the wool and the cold from tiles/slates will cause it to condensate leading to bigger problems best remove it and let rafters breath a little and then look at getting kingspan or the likes of that fitted between rafters it will let airflow be continuous and also has a vapour barrier in it so no need to worry about damp etc
Answered30 December 2019
16
Anonymous user
Take it out, if its damp as it could hold moisture against the timber and rot the rafters.. as for fitting a new breathable membrane in my opinion it would be pointless without renewing the roof tiles completely, better to leave it open and breathing until your ready or can afford the Arm and Leg needed to pay for a new roof where the new tiles will be laid on a waterproof breathable membrane. , there may be systems where you can spray a waterproof coating under the tiles but I would leave it open
Answered30 December 2019
1
Green Contractors Ltd
Rating: 4.9 out of 5
1 You can take the insulation out.
2. Buy a Soudall 25kg foam cylinder and a pro gun and then spray it all .
Is the best and cheapest option.
The tiles might be fine so it will be the case of striping all out and fitting the felt, you will need some battens etc
Good luck
Answered18 January 2020
0
Handimen (Home & Garden)
Rating: 4.8 out of 5
Hi
I suspect that the floor insulation is in need of updating to add against heat loss from (ceilings) rooms below.
It’s generally excessive loss of heat that’s causing the condensation problem.
The mineral insulation to below roof tiles is not helping & possibly blocking ventilation (so best to carefully remove this)!
Fitting tyvek (or similar) breathable membrane to the underside of roof joist should not only help problem but also look & keep loft area cleaner.
Hope this helps
Tony
Answered19 January 2020
0