Superior Walls precast foundation walls 2

[jayrod12]

Good Morning Everyone,

Has anyone had any experience specifying precast concrete foundation walls by Superior Walls?

We have a home builder that brought some details for these things and wants to know if we would allow them as an alternative to poured concrete foundation walls.

These walls have 2"x8" concrete studs at 24" o/c, a 2"x10" top and bottom concrete plate, and the face of the wall is 1 3/4" thick. We are still waiting on answers for reinforcing specs. These wall panels can come in varying lengths and heights. Generally pre-cast stuff is also engineered and approved by the manufacturer however they have made it clear that the liability for these walls to be installed here in Manitoba would be ours.

We understand there is a key provided to lock adjacent panels to each other and then a watersealant/waterstop and waterproofing membrane isapplied.

Anyone have advice or recommendations besides check the wall once we get the rebar specifications?

 

[FSS]

Be careful with the foundation. They will just put on some gravel and call it good without a footing.

Point loads must also be specified so they can modify the walls.

 

[jayrod12]

Good points that I meant to mention. They want to use just a gravel footing however that does not fly in our office so they will be pouring a concrete strip footing below these walls.

Never thought about the point loads (Never really had to for standard poured concrete walls depending on magnitude) so we will have to note that. The other issue from a (excuse the Canadianism) Part 9 perspective is they are removing the interior frost wall and insulating between the concrete studs instead and so we have a large thermal bridge occuring at each stud. If they were to increase the width at point loads (to say a column roughly 8x8) it would be an even larger thermal bridge.

 

[XR250]

They are used around here on gravel footings all the time with very few issues.
Be careful about the top of wall inward bracing (to resist the lateral earth pressure)
The bracing details that are shown in the builder's packet are less than stellar.

 

[kylesito]

Interesting timing, I have been working on a project where these were specified and even had a thread going about it:

http://www.eng-tips.com/viewthread.cfm?qid=347679.

If you read through the thread, you will see that the end result of my experience involved us threatening to withdraw as the EOR if the owner agreed to allow the contractor to use them. That being said, before I launch into the issues, let me offer some positives. For what they are used for typically, they can be a viable product. They are fast to erect save a ton in labor wages. I think their use, however, is limited to only buildings governed by the IRC that don't require traditional structural engineering services. This largely boils down to the gravel footing issue.

For us, our building was governed by the IBC. When pushed for engineering data, we were first ignored and given the "oh, don't worry, we can design them to meet anything" or "why do you need data, we build these things everywhere". This disregard for engineering in the process was something that plagued our experience. Although we eventually got engineering calcs, we found them to be severely lacking in many respects (no interaction calculation for instance between shear and axial loads, no bending strength calculations, etc). Plus, we never felt satisfied with their rationale behind the gravel footings (again, the calcs failed to take into account anything about the underlying soil). After consulting with several geotechnical engineers about it, they were also not convinced a purely gravel footing would work.

Ultimately, I think our reluctance to assume liability on it prompted the contractor to go another direction. I am not saying it's a bad product, only that it, in my opinion, is not a viable solution for an IBC governed building.

One interesting note though about your case, we were insistent about going with the cast-in-place footings also throughout this process. Unknown to us, Superior was telling the contractor they weren't willing to install their product on a concrete footing and required gravel to "work". Once again, it was never proven to our level of satisfaction as to why this was.

However, I think it's important to note though that through our research we learned that each supplier is independently owned and operated and responsible for their own engineering data to support the product. So, the agency you are working with might have better resources to support their product than ours did and may permit its installation on concrete.

Bottom line, while there is potential in this, we ultimately concluded that the salesman was selling snake oil and had no experience dealing with a structural engineer or with a building of the caliber that it was trying to be applied to.



PE, SE
Eastern United States

"If a builder builds a house for someone, and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death!"
~Code of Hammurabi

 

[kylesito]

Also should add...we watched them fabricating some panels during this process and their method of setting rebar is all by "wet set". We didn't observe any bars set in place prior to pours. We also noted that they did not appear that any of their lintel bars above openings were long enough to develop in the wall panel beyond.

If you are going to take responsibility on it, I HIGHLY suggest implementing a QC procedure and reports.

PE, SE
Eastern United States

"If a builder builds a house for someone, and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death!"
~Code of Hammurabi

 

[msquared48]

Any time any contractor/supplier/ client, heck whomever, attempts to minimize or wave off my structural engineering concerns, I dig deeper, and usually find a pile of crap. Something stinks here...

Mike McCann
MMC Engineering

 

[jayrod12]

Thank you so much Kyle,

I've been leery since these were first introduced and your info seems to confirm my suspicion, they're promoting their product as a time and money saver but can't back it up.