ICF House Update

[beck3906]

Things rolled along well this week until the machine that makes the foam blocks for the ICF walls broke. The company is waiting for a part to get shipped in from Austria, so we'll be 3-4 days late on getting the remaining blocks for the walls. Anyway, I thought I would share photos of the ICF wall process.

The one photo of my wife holding a foam block is just a small piece that was cut from the window area. The area between the foam will have more rebar installed once the complete wall is built and then filled with concrete.

The walls will allow protection against high winds but not making it tornado proof. The struture will also be more more sound proof.

The idea would be to create an envelope where the house is completely foamed in so the attic will have about 6 inches of foam sprayed in. We hurt the effiency some by having windows, but you need some windows in a house.

 

[mredburn]

I built ICF houses. I built my own and my parents out of ICF as well. You might consider double paned insulated low E windows. WE also spray insulated the underside of the roof deck. I would also recomend that you use an asphaltic tape on the seam lines of your roof sheathing to seal the openings of your roof. This allows the expansion but wont let rain in if you ever loose your roofing in a storm. The product we used was called "FIre ans Ice" IT was 6inch wide asphaltic tape. You will need a fresh air exchanger on you a/c system as well. ICF houses are so air tight they can get stale inside. Are you building it yourself or having a contractor do it?

 

[beck3906]

Thanks for the suggestions. I'll look into a couple of them.

We have double-paned windows with an inert gas inside for most of the windows. We have a large window/door in the family room that I'm not sure about, but I think it is also an energy efficient design.

The roof deck will be sprayed with foam to complete the envelope.

We have a builder that is doing the work. We've watched a few of his houses over the last few months. A guy nthat works with me just finished his ICF house this past December, so we got a first hand look at the construction methods.

 

[mredburn]

I have large windows and a 12 foot sliding glass door. All the glass in the house including the doors are insulated impact low E rated. I'm posting a picture of the roof with the tape so you can see what it does.

we used 2 /38 ring shank nails to hold the plywood to the trusses. The nails will break or the plywood will tear before they will pull out. We built houses to with stand Hurricane force winds. The weakest points will be your your window and door anchoring and your roof sheathing attachments. The tape helps keep the rain out if the storm takes off your roofing material. Shingle tile or metal. We had to build to south Miami Dade hurricane codes.
When we built my moms house we put a special meter on the A/c system to measure the electric used to cool the house. It ran .89 cents a day to run the A/c at 78 in Southwest Florida. where its 93+ outside. WE used 2 stage A/c systems. You will need a fresh air exchange system with your a/c as well. Your house will be so air tight it can get stale inside very quickly.

 

[beck3906]

My friend that built the ICF house found out just how tight they can be. He turned on the vent hood over the stove and discovered it was so strong that it pulled the smoke out of his fireplace.

 

[mredburn]

Heheh The first one we built we had an energy efficiency audit done. They put a fan in the doorway between the house and the garage and suck all the air out of the house. The toilets started bubbling as it pulled the air backward up through the septic tank. IT will be exciting for you I'm sure.