My wife and I are in the early stages of building our own home (target date is a few years out still) and I am in research mode.  I'm trying to find information on ICF home builders/contractors in northern Utah and struggling to find much.  If anyone knows good ICF builders in northern Utah I can contact, please let me know.

The other question I have is about multilevel homes.  Can ICF walls on upper levels only be used directly above lower level concrete walls to ensure structural integrity?  I've poked around on this a little and not found a very definitive answer.  Is it a better idea to do ICF for basement/lower level and then use SIPs for upper?

Thanks for the help.

JPWhite

Sorry, I can't help with the contractors, a little out of my territory.
However, I will try to answer some of your questions.
The ICF walls should always be alined from level to level. The concrete in an ICF wall is extremely heavy. Providing support for that weight would extraordinarily expensive, and unnecessary. Also, one of ICF's main features is its strength, which is derived, at least in part, from the direct connection to the lower levels and into the ground-tied footers, by means of the concrete and steel rebar connections. Once this continuous connection is broken, the walls' resistance to shear forces (wind) is reduced to the point of ineffectiveness.
If you must offset the exterior walls from level to level, then use ICFs for the lowest (basement) level and then switch over to SIPS. However, I would recommend that you not offset the walls. You will get a home that is much less expensive to build and to maintain.

Hi JP.
Without your drawings in hand I cannot offer much advice. However we have done multi-level ICF structures with walls sometime set back on the upper level(s).
Often there is no trouble with the spans involved, sometimes a column may be required.
Don't go to Sips unless you must; while they are far superior to stick frame (regarding absolute R-value and little air leakage) they nowhere match a good ICF wall, IMHO.
If you are able to email your drawings to [email protected] I'll give you my opinion as to the viability of what you hope to do.
Keep well,
FM

Where are you located in Northern Utah? AllSteel Distribution is a licensed General Contractor out of Southern UT but they have worked in lots of different places. www.allsteelllc.com is the website.

Rick

Thanks for the replies.  I did end up finding a couple of local contractors that are experienced in ICF.  I believe they use the LOGIX system.  I suspected as much in regards to aligning upper level walls with lower.  I had just never seen any distinct statements on the matter.

We haven't settled on any specific plans yet.  Otherwise I'd be more than happy to send them off for opinions.  I wanted to uderstand some of the things about ICF construction before picking a design.

Another issue that I'm curious on and haven't seen too much information is how ICF homes hold up to an earthquake.  In Utah we certainly aren't concerned with hurricanes and only on very, very rare occassion a tornado.  When the big event happens here it is almost assuredly an  earthquake or winter storm disaster of some sort.  I've frequently seen the strength information of ICF homes related to wind and debris impacts, but have found very little on earthquakes.

Also, I haven't done much research yet into what type of flooring/roofing systems are best to use in an ICF home.  I didn't know if there was some better option besides the standard stick frame approach to floors between levels and the roofing construction.

If anyone has any reliable information regarding these other issues I'd appreciate hearing it.

Thanks

JPWhite

JP,
Steel floor joist and roof trusses are a great interface with ICF construction. Embeds are easy and there are no extra steps involved; just place your embeds where you need them then place your trusses and screw them on. We have done concrete roofs and floors over the steel trusses. There are a lot of choices depending on your style of home and your preferences. We have pictures of what that looks like on www.allsteelllc.com

Rick C

Posted By jpwhite on 21 May 2010 10:57 AM

Also, I haven't done much research yet into what type of flooring/roofing systems are best to use in an ICF home.  I didn't know if there was some better option besides the standard stick frame approach to floors between levels and the roofing construction.

The best floor and roof system for an ICF home is the one that best fits your needs, all things considered, including economics. You can hang any kind of floor inside an ICF shell. There are several types of concrete floors, including slabs, steel beam supported, integral foam forms, etc., but I'm not familiar with the details on them. If you're using in-floor radiant heat, or going after passive solar heat, then concrete might be the best. Wood joist floors also work good for radiant heat, and are probably some of the easiest and economical to install. Floor finishing has a bearing. Concrete can be stained, or finished with any usual material. Hardwood makes a good choice if you want to minimize dust. Floor strength needs to be stronger for tile than carpet. Joist spacing and size can be varied to accommodate varying dead and live loads throughout the house. I used I-joists because they're economical, readily available, and easy to install. I used Advantech subfloor material because it's stronger than either OSB or plywood, priced in between, and the guys on a tile forum swear by it. I-joist spacing was adjusted for heavy load areas such as the bathrooms. Keep in mind the china closet, or grandfather clock, test. Do you want to hear dishes or chimes rattle when you walk or jump on the floor? Do you plan to use stone, or tile? I'm sure you get the picture! Since you're doing ICF walls plan to do a conditioned crawl space, if you are having a crawl space.

Your roof design depends on what you plan for roofing material, such as steel, asphalt, tile, etc., what you want to for insulation, whether it be roof or ceiling, what you need to do for water vapor control, and the configuration of the roof, i.e., ridges and valleys, dormers, and so on. Some parts of the country still prefer to hand stack rafters. Other areas use nothing but trusses. SIPs make a good roof, but may cost more. A double layer roof (a second layer of sheathing on 2x's on top of the primary sheathing) has advantages. Cathedral roofs have special considerations for ventilation and insulation. You can put any kind of roof on top of an ICF shell.

For both systems research everything you can and mesh that information with what you can afford and what you want in terms of comfort and aesthetics. There have been boo coo discussions of floors here in the past few years.When you make your choices stick with them, don't look back, and don't let anyone tell you you could have done better.

Here is document that will answer your questions regarding ICF structural engineering.

It gives you insight into earthquake resistance and wind resistance and multi story concrete structures
http://www2.huduser.org/portal/publications/destech/icf_2ed.html

Thanks for the tips *dmaceld. If there aren't any significant drawbacks to the standard I-joist setup between levels that is likely the route we will take. If anyone knows of any drawbacks I may be overlooking, please let me hear them. Our roofing will be the asphalt shingles, but I'd like to make sure the roofing system is tight enough to match the ICF in the rest of the home.

Great reference *focusonz. Thank you for that. It looks like it will make for a good read.

JPWhite

Posted By jpwhite on 21 May 2010 10:57 AM
....
Also, I haven't done much research yet into what type of flooring/roofing systems are best to use in an ICF home.  I didn't know if there was some better option besides the standard stick frame approach to floors between levels and the roofing construction.

If anyone has any reliable information regarding these other issues I'd appreciate hearing it.

Thanks

JPWhite

The "best" floor/roofing system depends on many factors.

For my ICF home I will be using custom designed open web engineered floor trusses (steel plated wood 4x2), 18" deep.  This will allow me to run my HVAC duct work, plumbing, and electrical through the open spaces between the top and bottom chords of the trusses.   The trusses will be top chord bearing and will hang on a ledge at the top of my ICF basement walls.

For the roof, I will be using engineered 2x4 roof trusses.  I have a simple roof design, so this works for me.  If you have a complicated roof structure, this might not be the best option. 

I also have a reputable truss designer / manufacturer <10 miles from home.

Here is some info on floor trusses:

http://www.hgtvpro.com/hpro/bp_fram...41,00.html

Thanks *arkie6.

From a preliminary look, I quite like the floor truss systems. Any idea on cost comparison to standard I-joists?

JPWhite

I have another question that has come up. For the upper level walls that are not above lower concrete wall, but are inside the trusses, what is a good way to build those and keep the tight, energy efficiency that I'm going for with the ICFs? Should SIPs be used for walls in the trusses or is standard framing with insulation in the attic space just as good?

Thanks to everyone for their input. It has all be very helpful so far.

JPWhite

Posted By jpwhite on 26 May 2010 10:13 AM
I have another question that has come up. For the upper level walls that are not above lower concrete wall, but are inside the trusses, what is a good way to build those and keep the tight, energy efficiency that I'm going for with the ICFs? Should SIPs be used for walls in the trusses or is standard framing with insulation in the attic space just as good?

Thanks to everyone for their input. It has all be very helpful so far.

JPWhite

One option if you are using trusses for the roof is to have the truss manufacturer build attic or room trusses, then strap inside the vertical 2x4s with ripped 2x4s running horizontally, aka "Mooney Wall" as described in the link below, then cover the outside of the vertical 2x4 walls with ~1" thick foil faced polyiso insulation board (foil side facing the unconditioned attic space).  This would give you a strong, relatively low cost, ~R25 wall assembly assuming cellulose insulation is used along with 1/2" gypsum wallboard on the inside.  Another option would be to fill the cavity with open cell spray foam; although, that would probably cost more and not really provide any real benefits over the cellulose.

Mooney wall:

http://www.builditsolar.com/Project...eyWall.htm

Here's the complete URL

http://www.builditsolar.com/Projects/Conservation/MooneyWall/MooneyWall.htm

The great advantage of ICF in my mind it is an easy DIY, no heavy lifting or sharp tools required and you can sculpt practically any shape you want out of Styrofoam.

Go with light gauge steel trusses for interior floors, light weight and strong and easily assembled and lifted into place.

Then go with UAD, Underfloor Air Distribution.

The house has a hot air system but no ducts. An electric heat pump uses a loop of circulated water buried deep in the ground, teamed with a novel air distribution system. 16" open-web floor joists create a hollow floor plenum for distributing air throughout the house with no ductwork. Conditioned air is pumped into the plenum from a centrally located air handler. This system works well because the house envelope is very tight and well insulated. Infiltration loss is low, and air temperature stratification is minimized. Conditioned air is not forced through at high velocity, but seeps out at a comfortable, barely perceptible flow.

Return air is collected on the second floor through a dropped corridor ceiling and at the first floor through the air handler closet louver door. Air is supplied by an air-to-air heat exchanger that modulates the incoming air with temperate exhaust air from bathrooms and kitchen.

Then go with a lite deck for a flat concrete roof with insulation built in. http://www.liteform.com/Lite_Deck/information.html

Then go with a non structural roof assembly (not trussed) on top of the lite deck. No sheathing required just rafters and standing seam steal roof planks.

I like Integraspec http://www.integraspec.com/
I like TF systems http://www.tfinsulatedconcreteforms.com/
I like these systems because.

1. The blocks are folded for shipping or your will call so more product per load
2. You can build curved structures
3. Less expensive than others
4. Integraspec has complete window and door buck solution
5. TF system has tall wall and is more easily trimmed for size

Designing a home is a matter of trade offs. Add a feature increases cost but you have to take away a cost to stay in budget. Reducing the cost of roof structure lets you add cost of insulation in ceiling. Eliminating cost of duct work lets you add any nice amenity.

Snaking around that hose from the concrete pumper is a bit strenuous but the pumper operator often times does that for you while you consolidate with vibrators.

When you pull a permit to build an ICF home be prepared to have a structural engineer review and stamp your drawings. Most municipalities require structural engineer to sign off on concrete shelters. And the structures guy will want a soils report on your site before he will even look at your building design.

Oh oh! I don’t know exactly where you live but certain parts of northern Utah are off the chart in an “E” Seismic Design Category. You got to stick with stick frame in an “E” and a concrete roof in a “D1” or “D2” is probably not doable in a reasonable budget. It looks like all of northern Utah is “D1”. And In a D1, I would only go with an earth contact approach where you have only one above grade floor and a below grade living space restrained on three sides

I hate to burst your bubble, let’s go float the Green and Colorado through Cataract Canyon instead. I got stuck in Spanish bottom and had to be jet boated out, when the Colorado River was running 100,000 cubic feet per second and never did see the Canyon.

%g Seismic Design Category E D2 D1 CBA

Utah Geological Survey

Earthquake Ground Shaking in Utah

In a properly designed ICF home you can watch in your living room CNN live - the forest fire raging beside you, the tornado blowing over you and the earth shaking below you.

Thank you for the suggestions *focusonz. I'll check out the systems you mentioned.

I had a hard time completely understanding that last portion of your post. Are you saying that building an ICF home in Northern Utah is not recommended and that stick frame is a better option? Or that it is doable but only at great expense? In the document you linked to earlier about ICF structural engineering, it seemed the main difference in engineering for different seismic zones is the rebar size and spacing in the concrete. Do you know a cost difference in that regard when designing to D2 rather than to a C zone? In one of the links you posted, it said that stick frame sustained less damage in earthquake loading than and UNreinforced concrete or masonry home, but didn't say anything about reinforced concrete. From looking at the map we should be located in a D1/D2 area of Northern Utah rather than an E.

If anyone has any good sources for comparisons between stick frame and ICF in earthquake loading I'd be very interested to see them and how they compare.

JPWhite

The document Prescriptive Method for Insulating Concrete Forms in Residential Construction as I recall doesn't give a design for "E" and if I remember without cracking it open that certain features "2 story above grade" cannot be obtained in "D2" while in "D1" you have to have so much solid wall and what windows and doors you can put in make the home look like a block house. In "D1" and D2" your lintel stirrups and rebar requirements make the home rather expensive.

You just have to study the document draw up the floor plans you want and see if it fits in with the prescriptive method and iterate the process till your satisfied. Then just go down to you local rebar and concrete suppliers and price it out.

A lot of people around here, the New Madrid seismic zone "D2", just do an ICF walkout/basement and put stick frame above. I in the middle of "D1" do an earth contact with a concrete roof with short roof spans.

You have to look at %g Seismic Design Category E D2 D1 CBA map find out where you are and follow the method.

If you are close the the Wasatch fault you are in an "E", that shaded gray area on the map the method does not address suggesting that you should build stick frame above ground only and an ICF walkout/basement.

The reinforcing prevents catastrophic failure resulting in the entire collapse of the structure to protect the otherwise statistical victims. My uncles slab on grade stick frame near the San Andreas fault during the last big one out there in Los Gatos, CA did not fall down but the un-reinforced concrete slab split in half

Life is full of probabilities. You can build anything you want but using the math you can contemplate the likelihood that you will be crushed by falling concrete or skewered by a wind driven 2X4 or Bar-B-Q’ trapped in a forest/brush fire or go broke paying for skyrocketing utility bills or raise an family and die in your sleep at age 92 with a smile on your face and happiness in your heart knowing you did your homework and survived.

Hillside fire ICF survivor

F5 tornado ICF survivor.

Unreinforced Concrete block first floor of 3 story building non-survivor.

Earthquake ICF survivor

Check with FEMA. I believe they have a publication on buiilding disaster proof structures.
Try this link:

http://www.fema.gov/plan/prevent/earthquake/codes.shtm

Thanks *BrucePolycrete and *focusonz for the information. The "Prescriptive Method..." document does not spec for zone E. My target was D1/D2. I'll have to go review that document again.

There appear to be quite a few FEMA docs that will be of use, or at least of interest.

It is great to get this info as early on as we are in the process.

JPWhite

I too am researching icf in northern utah (utah county)  Any useful info on the issues you've discussed--especially contractors and seismic findings--would be appreciated.