One way to build without footings is to use precast concrete wall systems and use crushed stone with a steel reinforced footer beam to replace the standard conventional concrete poured footings. “Superior Walls”, having licensed dealers around the country claims that in their system the walls distribute the weight better, are 10 times stronger and 20 times faster to build, being warmer in winter and cooler in summer. As a former Realtor of 12 years, I always prided myself on sharing the pros and cons of having a home built when my clients’ interests moved towards new construction.
The strength comes from the fact that Superior Walls concrete wall panel has concrete studs reinforced with rebar and polypropylene fibers. The warmth comes from the 1 inch of DOW insulation with an R-value of 5 for the original R-5 wall, with their newly improved Xi wall system having 2-1/2 inches of DOW insulation which has an R-value of 12.5. It’s fast to put up, because the walls are custom built and prefabricated in a factory, delivered and then erected with a crane. The concrete panels also have built-in accesses for wiring and feature stud facings to easily install drywall with screws. It might sound similar to a prefab modular home, but they are not modular and don’t look modular.
Superior Walls are contributing to a greener environment because their system reduces energy leakage, lowers energy cost, saves on valuable resources, improves indoor air quality, and has no on-site soil contamination. They have achieved LEED certification, the American Institute of Architects Green Specs, and the National Green Building Standard. They have been featured on TV on 13 episodes of “Extreme Makeover: Home Edition” as well as being featured in multiple episodes of “This Old House” for the 2007 Carlisle Project, and the 2008 Weston Project.
However, what they have soared at with respects to accolades, they have fallen short with water proofing. They have addressed the water issue somewhat, but in my opinion they could do more. They have suggested that if you plan to further insulate the cavity of the already insulated concrete walls, that you should consider styrofoam or other closed cell insulation products over the blow-in insulation or the itchy pink fiberglass batts. Those open cell insulation products can create a moisture problem whereby moisture in the air penetrates the insulation and reaches the cooler wall surface and causes condensation. Another moisture preventative technique they use is a specifically manufactured concrete sealant and it is this one part polyurethane sealant that is used to seal the panel joints when the walls are joined together. Additionally, the concrete foundation walls themselves are made of a special low water/cement ratio concrete that they say require no additional damproofing, and the crushed stone underneath in lieu of the poured concrete footings act like a french drain, draining the water away from the home.
Now alot of these ideas are good ideas, and not using poured concrete footings is not something I have objection to whereas stone underneath has been substituted with success up north in colder climates. I also do not particularly take umbrage with a concrete foundation wall. What I do have a problem with is comments I saw by some builders on a message board about this very system. One contractor stated the issue seemed to be at the corners, whereas the walls are only bolted together and then a sealant or caulk is used, which in his opinion didn’t fully protect against water intrusion. He also noticed this happened with a home that had a basement (or cellar). He did however note, that he had another friend that used the system and has had no problems.
So it could be that the caulk used was not an outside caulk or the elevation of the land (lot) was not condusive for basement building. Perhaps the property was not properly graded to slightly slope away from the property, or perhaps there were other issues in installation and not in the manufacturing. These comments were made on a forum in 2006 and 2008, and so if it is a manufacturing problem, then it is important to note that they have improved the R-5 wall with a Xi wall and now an Xi Plus using a combination of foam insulation and Dow Thermax. Of course it depends on the type of soil one has, whether that be clay, silt or sandy loam, because some soils are better draining than others. This is particularly important when building a home with a basement.
TIPS: One option is granular backfilling for controlling frost heaving. This reduces the possibility of ice formation and frost on those poorly draining soils. Another suggestion would be using a geo-textile on top of the granular over the drain tile. You should also consider the frost line you have in your part of the country and ask your contractor if that can be altered artificially. Your builder can help you with answering both of these items. You will also need to ask your builder if these things can be done in conjunction with the Superior Walls system.
DISCLAIMER: Another note of importance is that after the crushed stone has been put in to act as your foundation, and the concrete walls are up, you will still need a contractor or builder to finish the home with electrical, plumbing, heating and cooling, and drywall. If you decide to abandon the idea of the Superior Walls system, you still may be able to build a regular stick built house using the stone underneath as a substitute for poured concrete footings. Although Superior Walls uses the crushed stone to distribute the weight of the walls and is contingent upon the crushed stone, that does not mean the crushed stone is contingent upon using those concrete walls.