“I'm seriously considering using ICF for a basement addition. One thing that concerns me greatly, however, is the selection of the appropriate product. It seems like most are very adequate and it really comes down to 'feel'. One area that there appears to be a great deal of marketing going on, though, is the use of vibrators. Which products *really* work best when using a vibrator, and why are the products so different? As this will be a finished basement, I want to make certain I do NOT have blow-outs or bulges all over the place. In other words, I want to be certain I select the correct manufacturer.”
A reply from a professional installer : “Amvic, toughest block on the market right now. Pay the extra price and ask for an upgrade from the plant to build up the strength of the form. It can be moulded to perform as a foam forming system over 3 x stronger than others on the market today. Reason, they have thier own manufacturing equipment and, if requested will mould blocks with higher density foams. However, be prepared to pay for the process. I have heard of numbers as high as $1.00 per square foot more for high density blocks.”
A reply from a manufacturer: “Without going in to how unfounded the previous discussion is, I will point out that by increasing the density of the foam in any block, it will likely void the parameters of the E84 tests, hence voiding the code approvals; if said block has such approvals.”
Finally, someone is willing to tell the truth! Not to mention that the increased density lowers the Insulation value and may not increase the strength of the form. The increased density just may transfer the “weak link” from the panel to the joint or even the tie.