# Options to cover/finish foil faced rigid foam



## asinsulation (Apr 11, 2011)

not too sure. you have a unique situation on hand. I know you are concerned about mechanically fastening the materials, but I think it would be your best bet. Adhesives WILL fail over time, where as mounting your foamboards in place with some foil tape, and then putting 3/8" drywall over the top of that and fastening everything together as a system, you should never have a maintenance issue any deeper then paint and spackle.


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## asinsulation (Apr 11, 2011)

also, keep in mind for any foil faced material to have its radiant properties, you need to have airspace. you may be able to save some cost on foamboard and apply that to the fastening by using bluebloard facing instead. same r-value and thermal properties without the radiant barrier which would be useless on this application anyways


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## dave_in_gva (Mar 8, 2013)

Thanks for the thoughtful replies.

I am leaning towards using 2 cm thick furring strips.

So from the concrete block wall moving towards interior I would have:

Concrete block > 2cm furring > 7 cm polyurethane (alu faced) > humidity rated drywall (1 cm).

That gives me a total buildout of 10 cm which is about the upper limit of what I can have without eating up too much of my cellaring space.

I did in fact call the insulation provider here in Switzerland and talk to their technical guy about the panels I am looking at. The reason I am after them is they offer the best thermal conductivity that they offer (0.02 W/mK). Like you, I was not so keen on the alu facing but wanted the product for the thermal properties. I would not have minded if the alu was on one side only and had it existed like that I would keep that side turned towards the exterior (i.e. towards the concrete block work). His answer was the internal facing may have some thermal reflectivity but given the ventilation going on in the wine cellar (it is an active wine cellar with constant ventilation) and the fact that the space would be empty of heat sources 99% of the time, it should not be a problem.

Regarding the furring strips - I am contemplating spending a bit of time and actually making these furring "discs" by cutting out say 6 cm discs of 2cm thick ply and having only these applied to the wall at the 60 cm on centre spacing needed to mechanically fasten my drywall. I have laser measuring equipment and am quite careful with how I work so I think I can end up getting my drywall screws biting into 2cm of ply with a 6 cm diameter target. I would then actually insulate the spaces between those discs as well, meaning I would gain in insulation value but give up the air space you mention. Did not know that an air space was important for the alu facing of insulation to have an effect.

Best,

Dave


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