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I am installing Triiso Super 10 foil to insulate the pitched & double height roof of my my byre conversion. However the manfacturers instructions refer to adding additional foam board insulation to the flat (horizontal) part of the roof to comply with buiding regs. My architect says that the foil is fine on its own. Can you advise on what I should do? I am keen to ensure a high level of ninsulation to improve energy efficiency.

Your architect has access to the insulation qualities of the roof construction you already have and if he says it complys to the regs then it probably does. If you want more then there is nothing to stop you putting it in.

Be careful, the manufacturers lit says that it will achieve 0.2W/msq K.

This is fine for sloping soffits, but with a flat soffit the regs ask for elemental level of 0.16W/m sq K. which means you will need additional insulation.

However the insulation value of the whole property is taken into account, walls, floors, windows and roof.

Your architect could have upgraded other areas of the build to compensate, so be guided by him.

Also if the project is under NHBC they might not except Triso-Super 10.
Not sure about Zurich.

I use this product on alot of my refub projects, its great, 30mm thick rather than 160mm+ makes a big difference in construction terms, particuarly if you want to expose the beams.

great product but not all local authorities allow it. For me in Cornwall they won't let you use it- if anybody knows different please advise as I would love to use it

Hello

does anyone know if Super 10 would be suitable for insulating a loft at the floor level in the loft between the ceiling joists, rather than in the roof pitch itself. We want to prevent the heat escaping into the loft and as the 1st floor ceiling timbers are only 100mm and the loft is boarded we wondered if Super 10 between the joists would be effective at all.

Also, is there any merit in laying 2 layers of Super 10?

thanks for your time

yvonne

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I would never use a multi-foil product such as Tri-iso Super 10 because it DOES NOT do "what it says on the tin"

The manufacturers claim that it will achieve a good U-value but the companies that have actually tested their product correctly now find that you are required to install approx 75mm of a polyurethane insulation between the rafters before covering with the multi-foil!!! Then with all the cross batterning that you are suppose to do before you plastyerboard - you may as well underboard the rafters with a polyurethane board and plaster which can be fixed straight through to the rafters without the battens.

Ycooke - I don't think that any of the products have been tested or certified for use at ceiling level and there are no merits of laying 2 layers - infact if done this could cause more of a problem as you don't know were the dew point will occur.

I used Tri Iso Super 9 (the previous version to the Super 10) in the restoration of my medieval house. It was the only product that I could find that would enable me to insulate the pitched roof and allow the rafters to be exposed. Having been working in the property for quite some time before the insulation work was done, I could sense an immediate and fantastic difference between how quickly the heat was being lost before and how well the heat was being retained afterwards within the upper floor rooms. And this was without any insulation to the solid brick walls at all!

Personally I think this product is fantastic. Especially as the idea behind it is not to store heat like conventional insulation (which obviously requires an amount of heat to be used in creating this 'cushion' around the house), but to reflect the heat back into the rooms where it is needed. I can't understand why some Building Control Officers will not accept it and others will. My property alone is proof that it works.

I think the architect is right! the foil is ok on its own and dont need some extra support

I wish to use a multi foil insulation material when repairing my roof. My local Building Control inspectorate at Bristol City Council are not satisfied with this and will refuse me certification to the latest standards. They wish me to use much thicker mineral wool instead which will raise the roof line and so look odd against my adjacent neighbour’s house. Can you help me get past Bristol Building Control with some third party accreditation?

If you check the Actis Triso 10 Spec sheet it is not recomended or tested for use on flat roof situations.

Leopo

If you have not already made a regs application then use an approved inspector. They want your business so are much more helpful and much more flexible.

Most accept tri iso.

Please note that there has been a recent determination on the dclg site throwing out manufacturers claims about multi foils so Council's will now be even more reluctant to allow this.

It is also good to read a post in this thread about how good it is. The products have been around for so long that I would have thought they would have been found out by now if they are no good.

hth

xavi99 wrote:Leopo

If you have not already made a regs application then use an approved inspector. They want your business so are much more helpful and much more flexible.

Most accept tri iso.


hth

Terrible advice. That just reads as ' Go to an approved inspector, they just want your money and will let you do anything" (not far from the truth to be honest). It sends a chill down my spine that building control is a 'business' first and foremost. Money first, standards second. Lets just do away with Building regs altogether.

Why won't tri iso get a BBA certificate? No BBA, no acceptance on site. Its not rocket science and it's certainly not LA's being deliberately awkward.

Other multifoil manufacturers have got BBAs and are accepted by LA's.

My advice is use a multifoil with proper accreditation rather than anecdotal and spurious claims. That way no problem will arise with LA building inspectors.

Alternatively, if you want to ignore the building regs, use the approved inspector, who will approve anything you like.