SCIP, SIP, CMU, ICF?
Hello all.
I am building a house in a hurricane/northeaster prone area of Virginia, and in an area that has potential for flooding to boot.
Keeping in mind that i dont have an unlimited budget, what do you think would be the best long-term, flood resistant, hurricane resistant home?
I love the idea of SCIP, but im not sure i can find skilled shotcrete people and the cost looks prhibitive
I like SIP, but i worry about flooding and hurricane resistance.
Im leaning towards ICF, but thinking it may be cheaper (and maybe “just as good”) to just to build CMU with foamboard
The house will be a three story box, approximately 28′ wide x 60-75′ long. Ideally with a roof deck.
I would appreciate your thoughts!
Chris in Virginia Beach, VA
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GBA readers,
In support of my program to reduce the number of confusing acronyms and abbreviations -- with the aim of beginning a conversation with an explanation, after which use of the acronym is permitted -- I will explain:
SCIP = structural concrete insulated panel
SIP = structural insulated panel
CMU = concrete masonry unit (concrete block)
ICF = insulated concrete form
Thanks Martin. I like the idea of concrete. I was in Puerto Rico a few years ago, and love the buildings with concrete roofs that somehow don't leak. But of course, they don't have to deal with freezing temps!
For Hurricane (and earthquake) resistance, and thermal comfort and airtightness, SIPS are excellent. But would not be best at levels subject to flooding. If a flood risk, first level should be of water tolerant piers or posts? Engineered helical screw auger pile foundation would give excellent ground anchorage and flowing water resistance, if you are in a floodable site. Key word is Engineered.
It doesn't take a "Michaelangelo of shotcrete" to do SCIP- just about any in-ground swimming pool contractor could do the shotcrete part correctly. The bigger problem is finding experienced contractors to do the rest of it, and getting the code people up to speed. Contractors trying new stuff (rightly) have to build in extra margin to cover the unknowns. It' won't be as competitively bid as going with the tried & true.
CMU with foam board can easily meet or exceed the thermal performance of minimalist ICF, but it's not quite as hurricane & earthquake resilent.
You should read resource information from The Insurance Institute for Business & Home Safety (IBHS). https://disastersafety.org
I was impressed after living in a SCIP house. But it's not popular in the US.
You should have no problem finding people who can do poured concrete covered with rigid foam - probably at a lower cost than ICF.
What a great community. I appreciate the quick replies!!
I am very experienced contractor, having done several hundred helicals over the years. I feel confident in a traditional concrete foundation.
Poured concrete....With traditional forms? I worry about going three stories with that/
CMU and a 6" ICF core wall are quite different in strength. A standard 6" core with rebar is tested to 200MPH winds and projectiles. Remember, ICF is basically poured in place concrete with the forms remaining in place after the pour. In addition, CMU with foamboard doesn't have the same R-Value as ICF with 2.5" on both sides. ICF like Nudura is ready for interior drywall with plastic studs every 8 inch OC and the exterior is ready for stucco. CMU requires framing wood walls on the interior and extensive exterior work for cladding to be installed.
Finding someone who knows how to do SCIP properly on a residential home is going to be VERY HARD to find in the USA. Sure, some SCIP people know how to do pools but doing a pool and a home are quite different.
Thanks all. Peter, I think you hit the nail on the head. I have even looked in Puerto Rico, thinking I could find some guys down there who could come up here easily to teach my local guys.
I think ICF may be the default answer in terms of water resistance, hurricane proof(?), etc.