Loft ceiling insulation

[theDIYkid]

Hi,

I have boarded out my loft for storage and want to sort the inside roof between the joists some insultaion to keep the heat in. I've looked at Kingspan and a few others similar but Im surprised at the crazy cost of this stuff.

The Length I need is 30 feet and the width about 18 feet, so the cost would be too expensive to do it this way, does anyone know a cheaper but good method of dong the same job at the same time blocking outside noise and keeping heat in.

Thanks
S

 

[freddiemercurystwin]

What kind of membrane do you have under the tiles? Is it breathable of the old fashioned felt or nothing at all?

If you have felt do you have continuous ventilation at the ridge and eaves?

BTW Kingspan and the like are not good at insulating from sound.

Normally insulation is all at ceiling level, or floor level when you're stood in the loft if you see what I mean.

 

[theDIYkid]

Hi, Thanks for reply!

Its felt under the times there is plenty of ventilation coming thru the roof and edges. I can hear everything outside in there people talking...I have wool insultaion under the loft boards which leaves room for ventilation but the cold is coming from the ceiling so if I stuck a radiator oil type up there the heat would go stright out the roof, so really want something that will 1. keep the heat in and 2. reduce the outside noise. Doesn't sound like Kingspan will do job from what you say, is there something else I can look at to dampen sound and keep heat in, I looked at the foil rolls that you staple to the joists?

Great username btw
thanks for help
S

 

[freddiemercurystwin]

So if you have traditional felt then unless you have continuous ventilation along the ridge then insulating the roof at rafter level is not recommended. Because there is no high level ventilation any moist air that gets through the insulation will not be dragged out by a breeze so it will just condense on the underside of the felt causing the timbers to get wet.

 

[theDIYkid]

Ok, so in any case I need to leave as is to allow air to move thru freely, thats a shame thought I could do something but take what you are saying, looks like a lost cause.
Thanks for advise

 

[freddiemercurystwin]

Sorry, its not an uncommon thing to try and do but is quite risky.