There are two types of basements that we were considering for the House Trade Built: a regular concrete form foundation or an insulated concrete form (ICF) foundation. ICF foundations are where contractors basically build your basement out of Lego pieces made of thick styrofoam. Traditional concrete form basements are formed between steel and wood sheets. Concrete is poured into the form, agitated to release bubbles and once dry, the forms are removed. Before this project started, I was 99% sure I wanted to do ICF foundation for one major reason: ICF acts as a huge insulator and makes it so that you don’t need to frame or insulate your basement which could save you big dollars.
The main downside of ICF foundations is that it costs about $7000 more to build it. However, this is to be saved when you don’t need to spray foam and frame your basement as the electrical can get cut right into the ICF blocks, and the drywall attaches right to it. Further downsides that I have heard are as follows:
a) Your excavation has to be very precise. Whereas with a regular basement, you can be a few inches out and make up for it at the top of the wall by making it level at the top, but ICF you can’t. It must be perfectly level at the base which is harder to do.
b) There aren’t many qualified ICF contractors in Regina.
c) Tradesmen don’t like doing electric and plumbing in the ICF basements, they prefer standard wood or steel walls. It may end up costing more if tradesmen dislike the work.
d) The method of securing drywall to the ICF blocks is not as stable as in wood.
I don’t know for sure whether any or all of these are true, but they are based off of feedback from people we’ve contacted in the industry.
After going back and forth on my options, I decided to go with a traditional concrete form basement. This decision wasn’t based solely because of the price. I would have liked the extra insulation for that cost, and saving on framing and spray foam wouldn’t have been a bad thing. But all combined, the negatives outweighed the benefits.
Below is an image of the concrete forms that Safrane Construction built for the basement.
We were fortunate to find contractors that have all worked together in the past on houses that made our decision much easier as well. We felt quite comfortable in the combination of Bergen Excavating doing our dig, and Safrane Construction to build the forms and foundation, and Ultimate Insulation to spray foam the basement that we decided this method would overall be our best choice.
Have you had any experience with ICF? If you were building a house, what would you do?