I have both Reward blocks and IntegraSpec blocks.  The styrofoam portion is 2.5" thick.   I tried to connect 2x4's to them using 3" screws.   Didn't work.  The screws just wouldn't catch the furring strips.   What I ended up doing was to drill a wider hole, like about 1" wide, most of the way through the 2x4.   This allowed the drill/driver to insert the screws about 3/4"-1" deeper.   That worked and produced a solid connection.

So I emailed both Reward and IntegraSpec.  Asked them what screws they recommend to attach 2x4's to their blocks.   Both replied 3". 

This seems to be a case of manufacturer's specs say one thing empirical evidence shows otherwise.    Oh well.  I suppose I need to buy 4" screws from now on to attach 2x4's to the ICF blocks.

Have any of you had the same experience?  I ask because maybe there is something I don't understand about how screws should be used to attach 2x4's to ICF blocks.

Never had problems securing 2x's to Integrarspec with 3" # 8 or 10 screws. Yes you need to have a feel for the drill gun you are using such that you don't strip the plastic web but a little practice and it should be no problem.

Use a impact driver, you will get the feel for it. Make sure you hit the tie as sometimes you think you did but may not have. When in doubt use another screw. Some use more wood then others and some use more glue then others. You will get the feel for it.

Here's my IntegraSpec to Reward connection...

http://tj.jjt.partyconnect.me/construction/walls/screwholes.htm

Notice the 1" bore holes I made to enable the 3" screws to catch the ICF furring strips? In the picture I used crate pallet (which I got for free) but the wood is just as thick as 2x4's and the same situation occurred with 2x4's. Without the holes that enable the 3" screws to penetrate deeper the screw just would not connect to the plastic furring strips inside the ICF's. Try as I may. I was hitting dead on into the center where the specs claim the furring strips are supposed to be. This phenomenon was occurring time and again, not just at one fluke location, with both Reward and IntegraSpec blocks. With a little more depth that the 1" bore hole provided the wood latched on tight and solid. So with the extra depth I was making a full-on solid connection.

Check your screws. I ordered 3" screws last time. But they sent 2.5".

The screws are for 100% sure 3" screws.  I'm going to give it another try when I have a little time on the ranch this weekend.  Maybe I'm doing something wrong. 

Posted By jacktca on 27 Nov 2012 05:58 PM
The screws are for 100% sure 3" screws.  I'm going to give it another try when I have a little time on the ranch this weekend.  Maybe I'm doing something wrong. 

If you are scabbing pallets, you might have hardwood. Try using softwood, ie spruce or pine.