Replies

1. 
   butch | Oct 16, 2005 09:48pm | #1

   I've applied masonite siding over foam before

   and the only way to do it was with a nail gun as

   the driving force of a hammer would cause the

   foam to compress. I don't know what the concrete

   manufactures suggest but you might want to check

   with them.

   Don't know if this helps...

2. 
   r | Oct 17, 2005 04:05am | #2

   I have no experience, but the second line of the Hardiplank installation instructions says, "Hardiplank lap siding can also be installed over foam insulation up to 1 inch thick".  They say just increase the length of the fastener by the thickness of the foam.

3. 
   shaarsta | Oct 17, 2005 08:43am | #3

   I sided my house with hardi-plank with 1" super-tufr foam insulation panels being used as the underlying sheething. I did not have any problems and have had good results. I used nail gun to install the siding, being sure to hit the 2x4 framing underneath. I was woried about missing the 2x4's and so I set the air pressure of the nailer on the low side so the nail would not shoot completly through the siding. Oftentimes however, the nail would not go in completely and so I had to hammer by hand the nail, but I felt that this was a minor inconvenience, for if I did miss the framing, it did not cause overly extensive damage to the siding.
   I did not have any problems with the sheething compressing around the nails.

   
   

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   Edited 10/17/2005 1:47 am ET by shaarsta

4. 
   drbgwood | Oct 17, 2005 02:41pm | #4

   I've never done a whole house, but I do alot of rotted masonite removal and replacing with hardi.  I also remove the rotted building board and replace with foam.  Haven't had any nailing problems yet.  

   Where I can blind nail, I use the gun.  Where I have to face nail, been useing those gav hardboard siding nails.

5. 
   moltenmetal | Oct 17, 2005 02:44pm | #5

   The planks themselves can handle quite a bit of flexure without breaking. The 5/4 cornerboards cannot.  Just the flex of the pallet when they unloaded it from the truck with the forklift was enough to do in all my cornerboards- every one was broken through in at least one place.

   Guess XPS (the pink or blue extruded polystyrene) as an underlayment would be less risky than EPS because it's more rigid.  Dunno if you can get the higher density (1.5 or 2#/cu ft) EPS in thinner sheets, or it too might be an option.  I'd be worried about having a really touchy installation if you went over the cheap 1#/cu ft EPS foam without furring.

1. 
   RodK | Oct 17, 2005 03:59pm | #6

   Thank you very much everybody, that gives me a much better understanding of what can be done, All the best,Rod