Hey Y'all! (yes I'm from the south). . . . . I'm thinking about building a residence. I am considering building in central Florida and/or the mountains of North Carloina. The subjects of my questions: Termites in slab on grade and ICF in crawl spaces 1. The locations I plan to build have very heavy to moderately heavy probability of termite infestation. This condition either limits or prohibits the use of foam below grade. In these areas what is your experience, how did you build foundation stem walls? 2. In western NC, a crawl space or basement is more common than a slab on grade because of the cold winter temperatures and the slope of the land. In a crawl space foam can not be exposed, therefore it has to be covered or removed. How did you handle this situation? THANKS!! I appreciate you sharing your experience! ps: I've looked at Build Block's and Fox Block's websites trying to educate myself before jumping in. Any advice about these or any other brands? From Florida code book> R318.8 - Foam plastic protection. In areas where the probability of termite infestation is “very heavy” as indicated in Figure R301.2(6), extruded and expanded polystyrene, polyisocyanurate and other foam plastics shall not be installed on the exterior face or under interior or exterior foundation walls or slab foundations located below grade. The clearance between foam plastics installed above grade and exposed earth shall be at least 6 inches (152 mm).

There are peel and stick membranes out there that function as termite protection.
Such a product will also acts as waterproofing.

Here's one such.

http://www.polyguardproducts.com/wp-content/uploads/2018/04/TERM-Flashing-Moisture-Termite-Barrier-R4-18-18.pdf

We have used and we very much like BuildBlock. We have used and we like Nudura and TF Systems ICF too. We have not tried Fox, but all ICF brands have gotten pretty well refined over the years and I suspect that they all work very well. Really, the ICF brand that you end up using is typically the one that is priced best for your local area and there are good contractors who are experienced using that brand. Properly done ICF is likely one of the better termite resistant building envelopes there is. I would recommend totally avoiding crawl spaces as there are better ways these days to achieve long-term maintainable/repairable plumbing and such. Research what is being used and done in your local area. You can find construction photos of our shop and home on our website which were both constructed using BuildBlock ICF.

Posted By Dilettante on 12 Aug 2019 06:07 AM
There are peel and stick membranes out there that function as termite protection.
Such a product will also acts as waterproofing.

Here's one such.

http://www.polyguardproducts.com/wp-content/uploads/2018/04/TERM-Flashing-Moisture-Termite-Barrier-R4-18-18.pdf

Thanks! I appreciate your response. A termite barrier will not work in some areas of the country. In Florida and other states that have "Very Heavy" termite probability building code says foam insulation CAN NOT be used below grade. (there is a map in the planning section of the code book) Foam has to be at least 6" above grade. I was hoping to see a comment from a contractor who builds in that area telling how they treat the below grade work then continue with ICF. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I've discovered that both Build Block and Fox Block offer a ICF that has a removable plywood form on one side. If there is a two sided removable plywood version, or if they sell the spacers individually so that I could attach larger pieces of plywood, that is what I would do.

Posted By sailawayrb on 12 Aug 2019 04:24 PM
We have used and we very much like BuildBlock. We have used and we like Nudura and TF Systems ICF too. We have not tried Fox, but all ICF brands have gotten pretty well refined over the years and I suspect that they all work very well. Really, the ICF brand that you end up using is typically the one that is priced best for your local area and there are good contractors who are experienced using that brand. Properly done ICF is likely one of the better termite resistant building envelopes there is. I would recommend totally avoiding crawl spaces as there are better ways these days to achieve long-term maintainable/repairable plumbing and such. Research what is being used and done in your local area. You can find construction photos of our shop and home on our website which were both constructed using BuildBlock ICF.

Thanks! I appreciate your response. I will take a look..... I'm not sure how many companies distribute ICF in my locations. I suppose a local manufacturer will be more cost effective because of shipping cost. If I can find local manufacturer or distributer nearby, I have the capability to transport the material the jobsite on my own vehicles. I also suppose material cost is pretty close to the same from one brand to the other. I still have to figure out what is best. . . . . I've been thinking about using the ICF materials for a long time, but just now starting planning and research. If you have any suggestions for material suppliers in NC or FL, I would appreciate it.

Posted By A W Warn on 12 Aug 2019 07:23 PM

Posted By Dilettante on 12 Aug 2019 06:07 AM
There are peel and stick membranes out there that function as termite protection.
Such a product will also acts as waterproofing.

Here's one such.

http://www.polyguardproducts.com/wp-content/uploads/2018/04/TERM-Flashing-Moisture-Termite-Barrier-R4-18-18.pdf

Thanks! I appreciate your response. A termite barrier will not work in some areas of the country. In Florida and other states that have "Very Heavy" termite probability building code says foam insulation CAN NOT be used below grade. (there is a map in the planning section of the code book) Foam has to be at least 6" above grade. I was hoping to see a comment from a contractor who builds in that area telling how they treat the below grade work then continue with ICF. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I've discovered that both Build Block and Fox Block offer a ICF that has a removable plywood form on one side. If there is a two sided removable plywood version, or if they sell the spacers individually so that I could attach larger pieces of plywood, that is what I would do.

https://www.icfmag.com/2017/09/termites-and-icfs/

https://www.icfmag.com/icf-comparison-chart/

Dilettante & Sailaway,
Thanks for the links. I've got a lot of reading to do.

One other possibility.

Go with an ICF system like Spider Ties. At least for the foundation/crawlspace.
Spider-Ties is a system where you mount the insulation inside double-sided wooden forms between the ties.
So what you wind up with is, essentially, a concrete sandwich wall.
You could also mock up the slab in a similar way. Exterior slab with rebar and wire mesh. Spider-tie walls up. Lay down a raft of foam on top of the exterior slab. Pour an interior slab flush to the walls.

It wouldn't be a PERFECT thermal break. As the interior of the spider-tie wall would contact the bottom (exterior) slab, and the top of the exterior spider-tie wall would be in contact with the floor and more conventional ICF wall above.

Still, if you really ARE limited (recommend lots more research) and sub-slab and wall barriers are just flat out VERBOTEN, then this may provide you with the best solution.

Polyquard term was used here in upstate SC. Footing and below grade walls were wrapped in it. Does have to be detailed right. Call them. They have pictures of the job. It was on Parris Mountain. David