5 COMMON ICF MYTHS
1- All ICF systems are the same!
ICF wall systems and installation procedures are definitely not the same, some systems come already molded together others are assembled in field, some have hinges that open the block and some are vertically installed others horizontally. Some blocks require much more time to install and have inherent issues with corner and wall bulging, if extra bracing isn’t used. Still others have a smooth interior surface allowing the concrete to separate from the interior foam wall. There is a huge difference in wall installation procedures between blocks, some systems require a large amount of foaming, metal starter track, wire block stiffeners and extra brackets even though the block purchase price is cheaper, “ancillary installation items” run the cost up considerably and actually slow installation time, which has a significant impact on sqft production.
2- Large blocks are easier and faster to install!
Most certified professional installers know that a large block may actually take a longer time to install, especially when it comes to lintels, headers, door and window openings. When a significant amount of cutting is going to take place, smaller “knock-down” blocks are easier to handle, cut faster and add a large degree of flexibility to trimming and bracing and actually go in quicker. A significant factor in installation is what is the “application” and how adaptable and flexible is the block? Some blocks can be cut on a table saw like a sheet of plywood while others have to be meticulously cut by hand saws, still others have to have abrasive blades in circular saws to make block cuts. These are block specific characteristics that significantly affect production time and duration of the project overall.
3- ICF construction has a lot less waste!
“fit” for the project. I have also seen jobs over 10,000 sqft where they had 4 trash bags of excess cut foam blocks. A large amount of foam waste is costly and just looks bad, although the total purchase price might have been less the end overall cost is much more expensive than a correctly fitted ICF block system.
4- It is easy for the trades to work with ICF systems.
Yes it should be, but again this is contingent on the expertise of the installation crews. If the crews don’t understand the mechanics of the ICF system they are using, they may not install the furring studs (imbedded in the foam) at the correct locations and miss block-outs, penetrations and just general issues that make the trades job extremely difficult and slow. For example, the drywall crews are use to a certain layout anything that deviates from 16”oc is potentially going to be a problem and probably create more waste and slow down installation. Another example is the electrician may actually have to cut through web-furrings because the manufacturers blocks do not allow for “channeling” of the electric wiring, this is extremely time consuming and burdensome.
5- We don’t have blowouts anymore.
Simply not true, blowouts still occur although much less frequently, mostly due to advances in ICF block manufacturing and more experienced crews. There are two types of blow-outs, one is called an installation blowout, usually due to inexperienced crews or inexperience with a particular ICF block system. The other type is a factory blow-out, there are a lot of new block systems out there that are more prone to blow-outs than others. In order to cut costs some blocks are less dense and less thick than other systems. Still others in the mold process do not “weld” the plastic webs to the foam. In other words the plastic that holds the blocks together during the pours is not internally connected to the foam. Ironically, this process in the injection mold portion of the ICF block manufacturing makes a significant difference in reducing blow-outs.