What kind of experience have people had with ICF floors and roofs? It seems like an ICF floor would be great for passive solar, and an ICF roof would be a strong, long lasting roof with great thermal properties. What do you guys think?

I'm building a passive solar right now using Insuldeck. It is a terrific product if you consider it during the design of the building. Trying to apply it to off-the shelf designs is more problematic. Use of Insuldeck appears to squeeze even more benefits out of the ICF walls in terms of height and strength.

Don't even try it with an inexperienced contractor unless they show good intelligence and the willingness to work with new things.

I love ICF flooring in theory and in practice. We have done quite a few of them. Roofs, on the other hand, are great in theory, though they still need more insulation in a Michigan climate; but are much too costly for most people in practice. The only roof client I had was doing a flat roof, and ICF floors are good for that. Problems occur when you want to install the deck on a pitch with both installation and application of the roofing. It makes the most sense to install the deck flat, then build the roof peak on top. This of course adds a lot of cost to the project, and the only real gain is strength, not insulation or thermal mass. You can easily insulate a roof to get the r-value needed, and the thermal mass of an ICF deck is on the wrong side in a roof application.
Bottom line: An ICF deck for a main level floor adds significant strength to a home, adds to its passive solar efficiency, and when colored and left exposed as the finished flooring, is cost effective. For the ultimate in strength and safety, an ICF deck for the roof is an excellent solution, but be prepared to pay for it.

We have regularly designed and built cast in place concrete roofs over insul deck. They are not much more expensive, if you do not place any other type of roofing material over the top, and you keep the pith relatively low. http://www.myspace.com/icfbuilder/photos/albums/album/581363#mssrc=SitesPhotos_SP_AlbumCover_ViewAlbum
This is a link to a site with photos of a cast in place concrete roof we installed, and placed cast in place concrete on top as an overlay, to create a step look. This is then coated in a sealant. The last one we placed, we added xypex to the mix also.

Gregory Fasano
ICON Structures LLC
239-438-2670

I have used Lite-Deck, very similar.

About how much extra did the Xypex add to the cost for a cubic yard of concrete.  Every time I talk to Xpex they tell me that Xpex will replace some of the cement but there still is a cost premium per yard.

I have used ICF flooring and roofing in my new house, and I very impressed...The ICF Floor & Roof System is a modular, lightweight, stay-in-place form made of Expanded Polystyrene  and used to construct concrete floors and roofs for commercial, industrial and residential uses. When installed properly the system provides structural strength through reinforced concrete and insulation through EPS.  The System utilizes 10 inch lightweight steel framing studs which carry the temporary construction loads until the concrete gains its required strength and act as furring strips to which interior finishes can be attached.  This system perfectly compliments your Insulated Concrete Form (ICF) structure and together they provide a complete structural and thermal “building envelope” for your floor or roof.

The EPS used in the green flooring and roofing decking system provides continuous insulation to your concrete floor or roof, which will provide you with an R-value of 17.8, or more depending on other materials used in conjunction with the system. The insulation is also highly effective at reducing the amount of noise that travels from one story to another.
_______________________________________________________________
You can know more about roofing Austin or Austin roofers .

I have used both Lite-Deck and Insul-Deck. Both are great products and the reps for both companies are very helpful. I personally prefer Insul-Deck. I use it for flooring, low slope roof applications and currently for a 6/12 roof application which is a lot more complicated. Cost is an issue but the end result is an indestructible fortified home. When you factor in the reduced sizing for HVAC equip, monthly energy costs and greatly reduced homeowners insurance, its not as costly as you would think.

Jim
J C Marshall Construction Inc.
[email protected]

One of the advantages of ICF construction is non-combustibility. Cold formed steel floor joists and roof framing are natural compliments to an ICF

I've seen ICF stairs - or I suppose ICF/SCIP - they had concrete tubes inside and concrete sprayed on the outside. Seems like a roof could be similar.

We have typically build ICF roofs with standard ICF panels, with pitches anywhere from 5.5/12 per foot to 12/12.
The steeper the better for concrete flow. Our last concrete roof included the overhangs in concrete and was poured at the same time as the roof.
The biggest advantage of this system, is storm protection. You can build with large tall gables and vaulted ceilings and still weather most of what Mother Nature dishes out.

Our current project is a flat roof “ gentle sloping roof “. Many curved walls, all floors and the roof this time around are insul-deck.

Eldon

totalicf@gmailcom

as a builder, distributor and insuldeck technical consultant/rep i would agree that exposed concrete slabs on an icf roof deck may not be a good choice in COLD climates. luckily that is were hurricanes or tornados are less of a concern, allthough joplin and other disasters have changed that perception. my opinion is not professional or sientific, but i would suspect concrete mass, once cooled down in northern winter temperatures will eventually draw a lot of heat out of the conditioned space, despite several inches of eps below the deck joists.

that is why we have successfully installed our panels on roofs without pouring the slab, utilizing the panel joists to create a concrete roof frame in conjunction with ridge/hip beams. this allows for any depth joist with eps inbetween (hi-hats can be added for more R-value) and a conventional sheated roof can be applied over it with concrete fasteners and sleepers, if a ventillated ( i believe they call it "cold roof") is desired.

insulation needs to be applied under and around the supporting beams (can be steel or concrete, or full walls). this makes for a fairly tight envelope, protects better than a framed/trussed roof in storm situations, and provides the ability for roofing geometry and look as needed. its also easier to finish the concrete just by screeding it flush with the panel, without having to worry about a clean slab finish on a steeper pitch.

added: eps panels such as retro, insofast or knockdown type panels can be added on top below the sheating, when needed.

i invite the engineers and experts to comment here, but i suspect the roof snow load capacity or resistance to negative uplift pressure is higher for a concrete to concrete reinforced connection than a strapped wood to wood connection.

anyone looking for more info please email me.

[email protected]
[email protected]