Hardie Board over foam board

 

I have 1 1/2" foam insulation installed on my house. We would like to
install Hardie Board over that, but the Hardie website states that it can
only be installed over 1" foam insualtion.

Can I still get away with it if I use longer nails or screws? Anything
else I should know about?


Thanks
-------------------------------------

 

On Nov 17, 10:03 am, btombs_at_kgsgroup_dot_...@foo.com (tombsy)
wrote:

You should call Hardie tech support and ask why they have the
restriction.  1.5" foam isn't much more likely to crush than 1" foam,
so I'd think that it has to do with the weight of the fiber cement
siding.  Maybe the siding sags over time as the actual point of
attachment is further away - the foam wouldn't support the nail by
itself and you can't nail it tighter to hold it more securely.

R

 

tombsy had written this in response to
http://www.thestuccocompany.com/construction/Re-Hardie-Board-over-foam-board-18271-.htm
 :
I contacted James Hardie and they said it was ok as long as I install a
Forene Strip or sheathing. Never heard of a Forene Strip (probably not
spelled right). Has anyone heard of this?

 

On Nov 17, 11:15 am, btombs_at_kgsgroup_dot_...@foo.com (tombsy)
wrote:

I think they probably said furring strip.  Google it.  That would
address the sagging situation.

R

 


On Nov 17, 11:15 am, btombs_at_kgsgroup_dot_...@foo.com (tombsy)
wrote:

What country are you in?

In the UK we would use battens to stop the foam being compressed.

Furing strips in the UK are normally tapered (eg as used to form a 1:40
slope on a flat roof) but I see in the USA Furing strips = battens.

http://en.wikipedia.org/wiki/Furring