SIPs vs. ICF in southeastern region
I am in the process of planning a one-level residential build of a 1300 sf house in the Atlanta, Georgia, area. We initially thought of using SIPs and have recently opened to the ICF product because of the threat of termites. I know the SIPs panels can be treated, as well as the build site. There is a local company that can do the ICF install and assist with finding other subcontractors familiar with integrating that type of build with their craft. I’m having a harder time finding SIPs installers–or anyone familiar with that method of building. They don’t know what to charge and I’m not sure what is fair. My husband and I are considering installing the shell ourselves, with the exception of the roof. Is one option better than the other or substantially less monetarily? In recent years, Georgia has had colder winters but I’m not sure concrete walls are justified and I think they might be much more. Any advice is appreciated.
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"My husband and I are considering installing the shell ourselves, with the exception of the roof. Is one option better than the other or substantially less monetarily?
If you are thinking of doing a lot of the work yourselves, ICF construction offers a substantial saving to DIYers that SIPs doesn't. And the consequences of getting things wrong during the installation is a lot more serious with SIPs.
Hi SidBeans -
You can imagine how complex this comparison is: cost, constructability, contractor experience, environmental impact...
This issue has also been addressed in previous Q&A: https://www.greenbuildingadvisor.com/question/sip-vs-icf.
On the issue of termites: while termites process wood as food, they will chew through just about anything to get to a good place to live or set up shop. So, you are likely to need insect protection for both ICF and SIP.
We did research on both SIP and ICF while I was at the then NAHB Research Center. Granted that was a long time ago (mid-90s) but neither system seemed very DIY-friendly to me.
Best - Peter
I built my home with SIPs years ago and when the framers doubled their quote, I did the work myself. Ugh.
I found that erecting the panels was easier than framing and raising a stick wall. As long as the factory keeps the skins square to each other, the panels go together quickly.
I was able to eliminate many headers, even on load-bearing walls, when there was enough panel above the window to transfer the load around the window. Your truss company might be able to help you by placing headers above the wall (in a raised heel). (You could even run the panels higher than the ceiling and then have the trusses fur the ceiling back down. This might provide enough panel to eliminate headers.) A simple gable roof will help to eliminate point loads that would need lumber in the wall.
If you build a service cavity inside the walls, specify NO electric chases in the panels. Bring your electrician in on the design to specify one or two chases for exterior lights, iff needed. Plan the kitchen and bath cabinets so that vents go behind cabinets until they can go up in a framed wall.
What you save on labor can justify the cost of SIPs. If you do the job right, your ACHs will be low. By eliminating headers, you also eliminate seams and thermal bridges (and save some money on the fabrication of the panels).
I don't know if the panel company told you, but panels can come 8' high by 24' long. It literally takes minutes to erect those.
After you school yourself, they are DIY.