Hello,

I have been planning a home utilizing steel construction with concrete board & spray foam insulation throughout. I live in the Caribbean and frequently incur hurricanes, I believe this to be the optimal setup in terms of cost, energy efficiency & strength. Based on my research the steel has superior strength, especially the roof, compared to the traditional cement/wood construction. I've been told several times to consider ICF's but I havent seen enough info to say ICF's are an upgrade to this plan, can anyone enlighten me as to why ICF would be better (if that is so) or not?

Any other forms of construction you think would be superior to the steel setup I described (Cost, Strength, efficiency) would be welcome as well. Another person pointed me to "Durisol" blocks? Still doing some research on this.

Thanks,
Jimmy

Jimmy,

Have you considered using fiberglass instead of steel for the construction of your home.  I mention this because of your site being so exposed to salt air and high winds.  See http://www.cbs-homes.com/    A big advantage to fiberglass is that it weighs less than steel and can be much stronger than steel.

If you do use light-gauge galvanized steel, then be sure to use at least G90 galvanizing.  You will also need to increase the gauge of the steel to meet local wind conditions.

Another approach might be to use red iron for the frame and SIPs for the insulation.

Clearly you cannot beat ICF for strength. Should you look at the cost of red-iron plus SIPs to create your envelope these costs will significantly exceed ICFs and still not offer extra additional strength. Given your climate you might consider ICF with fiberglass rebar as was implied above. If you want to build the best structure possible then go with SIP and/or steel along the lines of what Alton is recommending above for the roof but it is not possible to beat ICF for the walls. Regards.

I'm a huge fan of ICFs, and though I live in a SIP house (mistake) I can only say they are better than "conventional" stick frame (as far as insulation is concerned).
Back to ICF: Have you thought of an ICF roof? There are several options available; OP-Deck and Insul-Deck come immediately to mind. We sell both of these and can get you a quote from someone nearer to you.
Send your span requirements ([email protected]), or if possible a pdf of what you need to cover & we'll learn soon enough if this a technology for you.
Keep dry.
Felix

Posted By Alton on 28 Feb 2010 03:27 PM

Jimmy,

Have you considered using fiberglass instead of steel for the construction of your home.  I mention this because of your site being so exposed to salt air and high winds.  See http://www.cbs-homes.com/    A big advantage to fiberglass is that it weighs less than steel and can be much stronger than steel.

If you do use light-gauge galvanized steel, then be sure to use at least G90 galvanizing.  You will also need to increase the gauge of the steel to meet local wind conditions.

Another approach might be to use red iron for the frame and SIPs for the insulation.

Alton;

Posted By Alton on 28 Feb 2010 03:27 PM

Jimmy,

Have you considered using fiberglass instead of steel for the construction of your home.  I mention this because of your site being so exposed to salt air and high winds.  See http://www.cbs-homes.com/    A big advantage to fiberglass is that it weighs less than steel and can be much stronger than steel.

If you do use light-gauge galvanized steel, then be sure to use at least G90 galvanizing.  You will also need to increase the gauge of the steel to meet local wind conditions.

Another approach might be to use red iron for the frame and SIPs for the insulation.

Alton;

Galvalume SIPs are proven in the Caribbean, Florida and all of Gulf Coast areas, they weigh less than fiberglass about 1.8# per sq. ft. are also impact and termite resistant
We can refer to experienced builders available in the Caymans, Jamaica, St. Lucia, Trinidad/Tobago, Guyana and many other Caribbean Islands

In order to give you a fair cost and performance comparison, one should need to know and understand where you are wanting to build in the Caribbean.

howdy!
well, that's a good way to put it. nice insights regarding the matter, works well in clientele explanation and information resource option.
In most cases, the homeowner is the one that has already convinced themselves that ICF "is the way to go", they are only trying to determine the "cost/ value" in terms of building a new home with a limited budget. This is where the examples of utility savings, hurricane, fire and tornado and other durability marketing materials come into play.
For this example home, if the homeowner had already had ICF on the "want list" of materials, then presumably, other more efficient materials and methods were already considered so there wouldn't be any other cost impacts of using materials and methods that complement the ICF product.
have a great day everyone!

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http://www.caribcoat.net/services.html ---this site may be of some use

SCIPs are basically inside out ICFs - concrete on the outside and foam in the middle saves having to cover the foam. The concrete and foam thicknesses and/or strengths can be the same as ICF.

With some technologies such as Thermomass, the two concrete wythes may need to be thicker than an ICF wall for the same load.  The Thermomass system also protects the foam but the outer wythe of concrete is not counted in the calculations for strength.  That is, the elements in a Thermomass wall do not make it a composite wall.  However, the EASI -Wall insert by Precise Forms does form a composite wall so that both wythes of concrete can be counted.  Or at least that is my understanding based upon conversations with engineers.

This is a pretty cool video showing strength of ICF.

http://www.youtube.com/watch?v=ocEmJ_D-uP4

I agree with Alton, - GFRP rod (fiber glass rod) would certainly be the choice for corrosion prone areas. Durisol is also a great choice for the walls. Maybe consider Hambro for the roof?

ICF construction sandwiches a heavy, high-strength material (reinforced concrete) between two layers of a light, highly insulated one (EPS or foam). This combination creates a wall with many desirable properties: air tightness, strength, sound attenuation, insulation, and mass uses.

The solution you are thinking about is very much useful because its cost effective can provide you enough protection against most of the hurricanes as compared to wooden logs and planks.
http://www.usbuildingdigest.com/

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