Superquilt - what to do at Eaves

[Careful_Bodger]

How should such multifoil products be fitted into/around the eaves in an 'under rafter' application? My roof is not felted (so oodles of ventilation), and the ceiling is well lagged.

I am thinking that, say, 1" battens can be fitted vertically in-line with the rafters (I dont intend to board over - just leave the foil surface exposed). This allows the thickness of the rafter as an air gap behind the tiles.

The manufacturer's websites dont seem the show the specific detail of the foil, the lagging on top of the ceiling, and the eaves geometry in a retrofit.

In addition, is Superquilt significantly superior than Airtec Double in such applications? (Any votes for Kingspan or celotex?)

Can anyone help?

TIA
C-B
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lynda, moderator

we can only move posts, not copy them

 

[topbanana]

50mm air gap needs to be left behind insulation.
e value of the product you are using should be available,from supplier and also the required value.
the insulation also needs to be solid, havent heard of super quilt but it doesnt sound it.

 

[Careful_Bodger]

Hi Topman,

Superquilt is a sort of multilayer space blanket-type material. You can apparently fit it above or under the rafter, depending on hot or cold roof construction in a new build.

I called the manufacturer, who said this should be fixed to the wall plate with battens. This is the same fixing method as for the rafters and ridge board.

Since my application is a retro-fit I dont think getting hammer and nails (and me!) under the roof slope is going to work.

Maybe solid insulating board might be easier to fix.........

Thanks anyway,
C-B

 

[topbanana]

ring the appropriate manufacturers and you will receive ample guides for construction.
this may need addition to your rafter (underneath) to gain space for 50mm air space and neccesary e value of insulation.
has this superquilt british standard approval?

 

[Careful_Bodger]

..which one did you have in mind?

See http://www.ybsinsulation.com/PDFs/Superquilt.pdf for the datasheet. I could not see any specific reference to a test standard.

Also, there is a discussion thread here http://www.screwfix.com/talk/thread.jspa?forumID=21&threadID=24683&messageID=279659#279659 which raises some doubts in my mind.

Thanks for your help

 

[topbanana]

BBA Certs.
have a search for that on your engine.
i read quite recently that they have no insulation that is being tested for a thin rafter application. that was probably on this site.

 

[TimSk]

According to my building inspector, superquilt 14 is approved and is a higher specification than tri-iso super 9/10. The point with these foil insulation blankets is that the tests used for them are different from solid foam boards. These things do not perform to spec in contact with other surfaces. There must be an airspace from other materials and the information I have seen is that a 25 mm batten is sufficient space from a roof or ceiling surface. If you do that they are very good and give values that should equal or exceed 100 mm of foam.
These products are very good for retro fitting as you can take a roll in through a loft hatch and staple or batten it to the rafters and as long as you tape the joints they will work very well. COnsider the problems of getting an 8x4 sheet of celotex into your loft! The rigid foams are great for underfloor or walls, but for roofs, these foil blanlets have sone real advantages.

Just for the record, I dont work for either Arctis (tri-iso) or YBS (superquilt).