Insulation

[Steveshouse]

Hi
Sorry if this has been ask before...

I am just about to buy a bungalow and on checking the roof space, I noticed the insulation was sandwiched between the underfelt and the rafters with a type of brown paper in between them.

To clarify it was tiles - felt - insulation (quite thin) - brown paper - rafter.

Could anyone please tell me if this a correct. There is no airgap and the paper is ripped in places..

Thanks
Steve

 

[Burnerman]

Incorrect, and there's an issue just waiting to happen.
There must be a gap between the underfelt and any insulation - at least 50mm - and there must be provision for ventilation.
On a bungalow, the best method is to put 300mm insulation between the ceiling joists, heavily lag any water tanks and make sure the insulation doesn't cover the eaves.
John

 

[Steveshouse]

Hi Burnerman
Ah your reply has just appeared after I edited my post????? Thanks

It is a dormer bungalow - it is the side of the roof opposite the dormer where I can gain access to the roof area. The insulation is to keep the upstairs a warm area.

I have tried researching on this type of insulation and not found a convincing answer. I have come across terms like kraft brown paper, does this mean anything to anyone?

Thanks
Steve

 

[freddiemercurystwin]

Burnerman is essentially correct, that said, is the insulation rigid or fibreglass type? Is the dormer/room in the roof original or was it a conversion? If so how long ago? Have you actually checked there is no gap between the insulation and the felt? Are there ridge vents? are there eaves vents?

 

[Steveshouse]

Hi freddymercurystwin

The insulation is like the wool stuff and I could see the felt up against this insulation.
I believe the dormer is original and the bungalow in cica 1970.

There are eaves vents in the plastic soffits under the guttering but there are no ridge vents.

Thanks

 

[freddiemercurystwin]

Well technically you need a gap but all houses are different and I would say if its been that way since the 70's and (here's the proviso) there is no sign of rot or deterioration of the timbers or condensation evident (if you can get access to see) then you can leave it as it is. When funds permit or you wish to upgrade the insulation then do a pukka job at that time.

But if I was the seller and there were no problems evident I would not be entertaining a discount.

 

[Steveshouse]

Thanks for the reply.
I asked the question if there has been any work done and the reply was on the opposite side where the dormer is.
All your replies suggest air gap so I have booked to go back and will penetrate the felt and see if there is an air gap above the felt.
Cheers

 

[freddiemercurystwin]

Thanks for the reply.
I asked the question if there has been any work done and the reply was on the opposite side where the dormer is.
All your replies suggest air gap so I have booked to go back and will penetrate the felt and see if there is an air gap above the felt.
Cheers

Err I wouldn't go penetrating the felt, that's the last thing you should be doing. If that's what you meant?

I mentioned that an airgap was good but if there hasn't been on for 30 odd years and there have been no problems then so be it. A problem is not likely to suddenly occur when you move in.

 

[Steveshouse]

Ok thanks -

I will not stick anything through the felt - just try and get a better understanding of what is going on up there and get further into the roof to test more timber with a meter.

Cheers