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Myth Question & Answer Session
I'm in the process of researching building materials for my home design and have come across ICF as an option. The home will be a custom designed, 6000-8000sq. ft, hillside home in Portland, OR. We're seriously considering ICF + dietrich tradeready steel flooring. I talked to a local ICF guy who is using ARXX. I read an internet forum that highly regards your opinions (see above), so I'd really appreciate your advise on a few questions:
1. I'm concerned about earthquakes / ICF. Can you make them seismic 4? I need to lean more about this, but it just doesn't seem to be good to be concrete in an earthquake, unless you have extra reinforcement.
Yes, Concrete with the proper size and placement of reinforcing is one of the best methods for building in high seismic areas. The structure should be engineered by a structural engineer and more specifically stated to resist seismic 4. I would add that most of the time, wind forces govern over seismic. When people think of earthquakes and concrete, they tend to visualize roads and bridges....these are columns and "beams", whereas a concrete house is more like a concrete box....picture a box tossed out on the water at the beach....the box rides the waves and stays together...picture columns and beams on the waves...they fall apart immediately. Proper engineering must pay particular attention to the lintels (small beams over upper story windows and doors) since these areas may (depending on the design) be the achilles heel of the walls.
2. a. What do you think about ICFs on a project like this?
This type of project is very typical for ICF. I would say that it is very fitting.
b. How do you route wiring on the ICF walls?
Wiring is usually run after concrete is placed, the roof is on and interior walls are framed (the normal time to place wiring). Wire is typically inserted into grooves that are cut into the foam with the use of an electric chainsaw, router or hot knife. Electrical boxes are anchored to the concrete with special screws. This is all code compliant. Depending on the brand of ICF you use, you may be required to install nail protection over the wire if the wire is not recessed far enough from the surface of the foam.
3. What do you think about ICF above grade? Or...Would you recommend only using it below grade? I will have a 1 up mid 1 dn (daylight basement) design.
I would suggest to you that you attempt to build the entire exterior wall envelope with ICF. If you are still in the design phase, you may want to insure that the design is "ICF friendly". If you only build a portion of the structure with ICF, you are building a "bucket with holes in it". If the design doesn't allow for ICF for the entire wall envelope, I would recommend SIP, Thermasteel panels, or conventional framing with sprayed urethane foam insulation (not necessarily Icenyne type) since the sprayed urethane acts as a good continuous insulation as well as an adhesive that "glues" the framing together making it super strong. To complement the insulative qualities of the ICF, you should consider good windows, doors and the sprayed insulation in the attic areas.....Don't allow your electrician to install the cheapo recessed can lights....the insulated ones cost a whole 2 bucks more on average and seal the attic from the living...saving a ton of $$ on heat etc.
4. Do you recommend SIPS on the upper floors w/ICF lower?
Only if the upper is not "ICF friendly". I like SIP and as a matter of fact was one of the first users of R-Control in Oregon! (Brownsville)
5. Any issues with ICF + Dietrich trade ready steel internal flooring?
I have heard (but not substantiated) that there have been some complaints about the bounciness as well as sag of that system. I have not used it. I am not sure about the cost effectiveness of the system....that should be considered on your project prior to completion of the plans and engineering.The concept is nice, but I don't see where it is all that it is cracked up to be for running ductwork etc.
6. Any issues with ICF + steel interior walls?
None that I know of. Probably 75% of the homes we build are topped out with steel framing. If anything, it may cost out of line, this is something you should research locally.
7. Any issues with ICF + radiant floor heat + gyp?
No issues, You answered your question below.....With radiant heat, you will still need to circulate air within the structure, especially to remove moisture. Many times, this ends up costing you the same amount that forced air heat would cost....Check out your options NOW, don't wait until the design is complete. Another option for you to check into is geothermal using both forced air and circulating hot water in the floor...only in desired areas, (limit the cost)....An idea.
8. Obviously, an ERV/HRV appears to be a great idea w/ICF due to the tightness...
Yes, this is a MUST. Check into all of the sites for these. A good website to start that gives tons more to go to is www.eeba.org There are enough links etc. to keep you busy for a century.
9. Do you have recommendations for contractors in my area?
The ICF Builders Network will be able to connect you with a builder in your area, or a way to get information on the builders in your area. Contact Us and we will be happy to assist you.
10. Problems w/ties and ARXX + stucco/EIFS?
I would suggest to you that you should concentrate on visiting sites of all brands of ICF, look at the quality of the install, visit the same sites all the way through the build process, knock on the doors of ICF home owners, ask tons of questions about the performance and problems etc. related to the ICF install and the particular brand of ICF....This will lead you hopefully to a good installer, the installer will tailor the brand to your project.
I hear there is a new variant coming in May 01 of ARXX without the exposed ties?
That's the story.....
11. I'm very concerned about health issues with the foam. I know that they do not use CFC's, but am still worried about the possibility of other issues...
If you build with "air tightness" in mind, you won't have any worries that you would have in a tight wood frame. If you choose a stucco veneer finish, BE SURE to have a 3rd party inspection clause written in the contract for the stucco sub...pay an inspector to visit the project multiple times while stucco is being applied.....if they don't detail around windows and doors correctly, you will get moisture intrusion behind the stucco....it will migrate into the house along ties, window bucks etc.
12. What system do you recommend? arxx? amvic?
I wouldn't concentrate on the brand of ICF until you are close to starting your project. I would design the walls as 12" thick. The reason for dodging a particular brand is based on these unknowns.... You don't know what may come around as a better system, don't know how the installed cost of the walls will vary by brand, don't know who you will want to install the walls, and they may have a preference for your project.