The construction industry has evolved over time based on consumers desires and price constraints. Tucson has not been immune to these shifts and in recent years we have seen a strong interest to have green building products and efficiencies incorporated into our clients custom homes. This desire for a green and efficient home has led many to question the conventional construction methods that have been used for decades if not centuries or longer. One product that was developed in the 60s and 70s is making a resurgence now.
Insulated concrete forms or ICFs are a type of building material that is typically used for exterior walls. ICF blocks are stacked to create a continuous form that is filled with concrete to create a strong and well insulated exterior wall for the home. In our industry these blocks are referred to as Grey Blocks and White Blocks. In my opinion both types of block have there benefits and drawbacks. Below is a description of the pros and cons of each along with some examples:
Grey blocks are great because they are typically made from post consumer material. This keeps non-biodegradable Styrofoam out of the landfills which is always a plus. Grey blocks are also very easy to shape and mold giving a flexibility in design that is harder to achieve when using a white block. The cons that we have found using grey block is that they don’t have precise dimensions. They can very by 1/4 inch in some cases making it difficult to stack and align. Another issue with grey block is it does not have any furring strips to attach drywall or lathing material to making interior finishing more difficult.
Many of the benefits of white block are similar to those of the grey block such as their sound insulating capabilities, rigidity, and fire resistance. What the white blocks have that the grey don’t though is their ease of installation. Since white blocks are completely made of Styrofoam they are much lighter than grey blocks. They also are precisely manufactured to interlock reducing the need for glue. Another benefit to white blocks is their integral furring strip or web. This allows easy installation for interior drywall and stucco finishing on the exterior. Some of the draw backs to white block is that it is slightly more expensive than grey. It uses new Styrofoam instead of recycling existing. Finally with the integral webbing design options can be fairly limited.
All together we think ICF is a great product for the construction of a home. There are pros and cons to each type of block that need to be considered but in the end the home will be strong, energy efficient and beautiful!