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I'm currently researching Insulating Concrete Forms to make walls etc.. and would like any opinion on using those instead of a standard foundation or block concrete foundation. I plan on putting in a full basement where I build.

Does anyone know of any "issues" in using ICFs in conjunction with log building?

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We built a Cape Cod style milled "D" loghome we built it on a full basement using ICF's. We did the construction on the home ourselves, we sublet the concrete yes I would use them again but I would form the ICF's myself as the concrete guy did not have anymore experience than we had on them. They are easy to setup and you can pour in cold weather, you must waterproof as with any other method you do need a pump truck. Cost was more than standard forms but the weather was cold so we saved time. This was in 1999.
Here is the episode from Bob Villa on this type of construction. I have no experience at all with this but I have had homes where the block leaked and another where the poured concrete walls were crooked and eventually the internal tie bars corroded away leading to leaks. I think no matter what you choose the preparation is the most critical with pea gravel and drain pipes.

The one thing about ICFs is that you cannot backfill until the floor joists are in for the first floor as the system is not stable until then. If you are going to finish the basement then they certainly have a big advantage. I think the latest use metal studs versus wood that I have seen in the earlier versions.
Thanks for the replies.

It appears to me that using the ICF's should be just fine, and since I will end up finishing the basement at some point (money flow depending), it may even be better.

Thanks for the help.
We built a Heritage log home (The Silvercreek 3244sf) on Lake Eufaula in Oklahoma using ICF's for the full walk out basement. We agree with the owners that it worked out even better than expected. The only drawback that we found at all was in pouring the concrete. That took a little more time than a standard pour.When building was completed we rocked using native stone from the property

. Ed Davis
I have seen them used for several years now on log, timber frame and stick homes. Easy to get a straight wall. Flexible to get higher ceilings. However, I don't believe the insulation values being promoted (EPS foam R-value at 3.85 per inch x 4 inches = R-15, not R-50 as marketed by some). Carpenter Ants love the foam for nesting and surface application of borates not enough (always treat the soil). Some walls are only 6" thick of poured concrete in the core (10" block), which doesn't seem stout enough for the weight of a log wall. 8" core minimum for me. If 10" core block being used, why not form and pour the wall instead? Some ICF's have shelf or starter blocks to support the exterior stone veneer weight.

All in all, they are as good as the crew is at installing.

ICF forms have been in use in Europe since 1964 and in US since 1985 (disclosure -- we are a distributor for Greenblock - the original ICF). Foam has a different R value depending on temperature -- the generally accepted rating is 4.4 per inch of EPS foam so blocks are rated at R22 to R24 before you account for the concrete. A 6" wall using standard 3000 psi concrete is more than adequate for any normal residential use so the concrete you save from a standard 8" poured wall will offset some of the cost of the ICF forms and labor. They are not a do it yourself project unless you have some experience with concrete work and they are poured on conventional spread footings.

In NH, we don't use block foundations so the other option is poured wall. ICFs have become popular with those trying to build an Energy Star or energy efficient log home. With a conventional stick built home, your easy upgrade for Energy Star is in the walls -- with logs you are already starting behind the curve so hence the use of ICFs to bring up the total efficiency. Ideal if you are planning on finishing part of the basement. The big downside is cost -- will add 40 to 75% to your installed foundation cost depending on availability and experience of local foundation contractors.

Yes the cost is the only reason that they are not used everywhere as it is great technology.
You need to use a laser transit or equal to pour the footings before you set the forms and the blocks require fair amount of bracing (more with some brands than others) to prevent blow outs when concrete is poured. Also some header details for any windows and doors. That is why you usually see it done by a foundation contractor.
Outside is parged to keep out water, sunlight, and bugs. With any foam on the outside of a foundation, a termite shield should be a standard detail.
In designing the homes one thing we have to be aware of is the additional thickness of the ICF walls. Many log homes have through bolts, or at a minimum the first course is bolted into the foundation. This bolt has to be offset from the outside face of the concrete a certain distance to hold properly. This means with the logs sitting on the concrete there is still 1/5” or 2” of insulation that is extending beyond the face of concrete and depending on your log diameter some distance beyond the face of the logs. Adding a stone veneer on top of this makes for a foundation that extends well beyond the face of the logs. This means we have to pay particular attention to the flashing and foundation cap. But to answer your question, this isn’t an “issue” but something that has to be paid attention to so the logs are sitting on concrete, not insulation, your bolts hold, and so that the log/foundation intersection can be properly detailed.

Derek Hurd
Gravitas, Inc.
1524 W. Hays
Boise, ID 83702
Twitter: Gravitasboise
We built a 4400sqft log home in 2007-2008 using ARXX ICFs, which have been used extensively in Canada for many years. The system worked well, our heating bills are low (remember that BASEMENTS are a substantial source of heat loss too!), and made finishing the basement a breeze as studs were not required.
You can see our construction of the foundation by visiting our website at:
The cost of the ICF system versus conventional poured concrete was NOT that much more - only about 15%, and we figure we saved on labor and heating costs, so it will prove to be a cheap investment.
Also, may I recommend that you look into the use of Form-a-Drain for your footer drainage...another big money is made by Certainteed.
We used 8" wall Logix ICF's for our walk-out basement. We poured the spread footing, keeping it very level and square. We stacked the forms ourselves, using a lot of HD zip ties to tie them together end to end and layer to layer. Loved the rebar pockets. If you alternate between two rebar pockets as you go up, the vertical rebar can be slid in from the top and the alternating horizontal layers hold it in place. We hired a crew and a concrete pump to pour. It was very easy to make a 9' wall so we can have 8' dropped ceiling inside. Walls are straight as a string. We are living in the basement now while we finish the upstairs and the temperature stays very nice year round with minimal supplemental heat or cooling.
We also used the Form-a-drain product, and we highly recommend that also. Drainage and Radon control all in one package! Best of two worlds.
We also went the geothermal route, which has been very satisfactory also, but that is another topic.
Alan, there is already a thread on this here
When we built our home the ICF blocks weren't that available in our area, but since then we have built several homes using the ICF blocks and have had a great success rate. They are about 30% higher in cost than standard concrete foundations, but the cost you save in not having to insulate and not having to use studs on the perimeter walls can even it out. Not to mention the time you can save and (backs) you save not using simon forms. If we could go back and do our basement over I would with out a doubt use the ICF.
This picture is of one of the homes we built using ICF forms and as you can see the homeowner went with a native stone around the foundation. It turned out very well.


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