Previously, I posted about the options for foundations and basement walls, and explained my intrigue with precast walls. Well, I finally had the chance to take a look at the product in person and I am certainly impressed.
My general contractor and I had many questions about precast walls, and decided to take an afternoon to visit the local supplier, Superior Walls. We met with Don Wagner, and he showed us their in-office displays, as well as a warehouse made from the Xi precast wall.
Superior Walls has been around since 1981, and started with the R-5 design for precast walls. They have been the foundation choice for over 85,000 new homes across America. They were recently featured on This Old House, HGTV and the diy network. Their claim is Dry. Warm. Smart. basements.
R-5 and Xi Precast Foundation/Basement Walls
Superior Walls has two precast products, R-5 and Xi. The similarities include:
- 5,000+ PSI Concrete for strength (typical poured wall is 3,000 psi)
- Steel Reinforced concrete studs, footer beams, and top bond beam
- 1-3/4” Concrete Face Shell
- 10-1/4” overall wall thickness
- Precast wiring, small plumbing, window, and door holes
- Tongue and groove system for wall sections
- Superior Sealant on ALL joints for Permanent Moisture Barrier
- Walls are reinforced with rebar and polypropylene fibers for extra structural strength.
- Galvanized stud facings for interior finishing
- Available Heights: 4’, 4’-8”, 8’-2”, 9’, 10’
- No additional dampproofing required
- Reduced build time (foundation set in less than a day)
- 15 Year Warranty against defects in workmanship and side wall water penetration
R-5 Specific Details
The R-5 product is the original Superior precast wall. The R-5 comes from it’s actual insulation R-Valueproduced by the 1” of DOW Extruded Polystyrene Insulation. Here’s a breakdown of unique features:
- 1” of DOW Extruded Polystyrene Insulation that runs continuously behind the studs and against the outer shell
- R-5 when installed
- May be insulated up to R24 after installation
- Around since 1981
What I Didn’t Like About the R-5 Wall
I don’t like the fact that the studs in an R-5 wall are not poured with the wall shell, bond beam, and footer beam. They are poured separately and installed with fasteners. I was also more interested in the Xi’s insulation than the R-5. While the R-5 will surely be warm and dry enough for code purposes, why not go with over double the R-Value with the Xi?
Xi Specific Details
The Xi precast foundation wall was introduced in 2003. The Xi is warmer and in my opinion, stronger than the R-5 wall. The Xi wall has an R-value of 12.5 when installed thanks to the 2.5” of DOW Styrofoam insulation.Here’s a breakdown of unique features:
- 2.5” of DOW Extruded Polystyrene Insulation
- R-12.5 when installed
- May be insulated up to R31.5 after installation
- Around since 2003
- Monolithically poured (poured all at once, studs and all)
- Meets or exceeds energy conservation requirements from both the IECC and the IRC.
My Likes and Dislikes of the Xi Wall
I like more about the Xi wall than the R-5 wall. I do however have a concern that the Xi product has only been around for 6 years (as of this writing), where the R-5 has been around since 1981. That being said, I would imagine the Xi was engineered to address certain issues with the R-5, while also improving warmth and dryness. I REALLY like that the walls are monolithically poured as one piece instead of the studs being added after the fact. I also really like the improved R-value for the Xi.
Some Notes From the Salesman
In our discussion, I asked a handful of questions as did my GC. Here they go:
Why do we feel very uncomfortable with the idea of NOT having a footer?
Answer: Everyone is at first. The fact is, the Clean crushed stone footing is every bit as load bearing as a footer, and the stone is often more level. It also provides the ability for water to flow out of the basement if it should get in
Why do you recommend one Auxiliary drain pipe around the exterior of the wall, as opposed to the traditional one inside, one out design?
Answer: Because crushed gravel is used, water from inside the basement can escape underneath the wall, rather than having to have a drain pipe internally that empties externally
So you mean to tell me you don’t recommend basement floor drains?
Answer: That’s correct (my GC and I will probably do the floor drains anyways…)
What type of water proofing should be used around the outside shell of the walls?
Answer: None, the high density 5,000 PSI concrete will be water tight (again, we will probably water proof anyways)
What goes wrong, and how many times have you seen it in your 11 years as a salesman for Superior Walls?
Answer: Wall sections have fallen in on the basement floor before. It has happened maybe 30 times in 11 years. They install about 1,000 foundations per year.
Why do the wall sections occasionally fall in?
Answer: Typically it is because the builder doesn’t follow the installation procedure for the floor joists, etc… For example, we require the builder to toenail the floor joists into the Bond Beam for stability. Often times, when someone is setting a modular, or double-wide, they forget or just don’t do that part.
How hard of a fix is it when a wall section falls in?
Answer: Easy for Superior Walls, but obviously very difficult for the homeowner if the basement was previously finished.
Does Superior Walls have an install crew, and do they use the same one for all installs?
Answer: Superior Walls does the installation, and each branch has it’s own install crew.
How do we avoid issues like the wall section falling in?
Answer: Have the saleman come out and inspect the floor joist installation and wall setup prior to backfilling and moving ahead
My Conclusion – What Did We Decide?
After seeing the product and getting my questions answered, I decided that I want to use the Xi product. We are doing a partial walkout basement for convenience, and I am almost certain that we will finish part of the basement at some point, so the precast walls will save us money in the long run. As it is, the cost for our home is only about $1,400.00 more for precast walls, than for poured concrete. I think we would have much more than that into studding and insulating the basement, if we decide to finish it.
I’d love to hear if you have any experience with, or questions about precast walls! Drop me line in the comments below.