Out of plumb foundation wall

[Greatone76]

I have a residential property. New construction. 10ft basement walls, 10" thick, reinforced. It appears they placed the walls as much as 4 to 5 inches over the height of the wall out of plumb. All of the out of plumb is the walls tipping out at the top. What is the line where we say we have a structural instability based purely on out of plumbness? I have seen the Kern value used 1/6 of the width of the wall. I know if the centroid is outside of the wall it is really bad. I'm guessing the numbers will check since the wall is reasonably reinforced to meet code required loads. My real question is what do you tell a potential buyer about the situation. The numbers work so you have no right to complain? It is just more likely to crack and have issues. Does anyone have a drop dead out of plumbness and reference I can use to require them to do something? Any thoughts on other ways to reinforce or help besides the standard steel tube behind the wall reinforcement? Are the tubes worth installing knowing the wall is just as likely to crack and have water issues? Is it just a waste of time. Being it is new construction I really don't like the situation for my client the potential buyer, but don't know if much will legitimately help with any reinforcement.

 

[oldestguy]

While it may be structurally OK, this fits in the category of what is the reduction in property value as compared to no tilt. For instance one can pose the argument that this out of plump construction is indicative of other aspects of the new house construction and accordingly puts a question on the true value. Thus, a reduced selling cost now or later is the likely result. Thus, the contractor might have to swallow some loss if things are not changed. Adding reinforcing on inside again is a bad sign that something is wrong, to the eye of a potential buyer. If I was a buyer I'd want a major value reduction if I would buy. One might hide it by grinding the visible part down, maybe.

 

[jayrod12]

With that level of out-of-plumbness, I question how do you build the wall above and think of the disaster it will be to finish it. I don't know about the ACI code, but I thought the CSA code somewhere has limitations to out-of-plumb tolerance.

edit: found the code reference in the CSA code

 

[PEinc]

Cut the basement floor slab back about 7 inches minimum. Attach some welded wire mesh to the existing wall. Then shotcrete the over the existing wall, from top of wall footing to or near bottom of floor joists, to make it look plumb with a minimum shotcrete thickness of about 2 or 3 inches at the top where the original wall has leaned in toward the basement. Patch the basement floor slab so it looks like it does at the other walls. Backcharge the builder.

http://www.PeirceEngineering.com

 

[Greatone76]

The entire basement is finished, so in terms of hiding it not an issue the walls are complete 2x4/2x6 walls in front of the concrete. It was supposed to be 2x6's, but the framing changed to 2x4's to make it fit the out of plumb walls in some locations. I have an overhand of the framing wall above the foundation wall of a couple inches at max. As the floor joists run over the wall it isn't a big issue structurally.

My issue is what is your argument to the building/seller to make them do something to re-mediate if it actually works numerically. The builder put it in, so they appear to have minimal standards, so what makes them correct it and then is remediation worth the effort, or do you just go forward with the risk.

=

 

[PEinc]

"Tipping out"? As in the top of the wall is leaning away from the basement interior and toward the soil outside? If so, you may want to consider adding some pilasters or counterforts outside the wall. This would need to be done one at a time with minimal excavation so that the wall doesn't tip further outward.

"If the numbers work"? It should be up to the builder to get an engineering analysis for the leaning wall with the outside soil removed. The wall was not built per plan or design. Don't let him off the hook. oldestguy made an important comment about a reduction in the value of the home. This may not be a big deal now, but will be when the house is sold in the future.

http://www.PeirceEngineering.com

 

[wannabeSE]

Has the soil bearing pressure at the foundation been checked?

ACI 117 has concrete tolerances. NAHB's Residential Construction Performance Guidelines is another reference. But, if there isn't a contract referencing either of these standards, I don't know what the options are. I have never done any residential work. All of my projects have had specifications that reference ACI 117. Have you check to see if the residential code has any construction tolerances? 5" out of plumb is a lot.

 

[Greatone76]

The issue isn't tolerance at this point. The residential drawings actually require ACI-301 specs which reference ACI 117, so this thing shouldn't be more than 3/8" over the height out of plumb. (Difficult to know what to use for a foundation all as the foundation section doesn't cover it and the competent sections says starting at the foundation) I used structure, cause there is nothing relevant in the foundation section.

Point aside the builder is selling the house that has been completed and sitting for a year. My client is the buyer and I continue to maintain that it should be remediated in some way. The builder has an engineer willing to sign off on it as is.

I have questions about pieces of the logic, but at the end of the day if he wants to be bold it is his stamp and I will sleep many nights better if one day nothing happens which mean I'm just a more conservative engineer.

I agree with oldestguy and the value being the issue.

Is it time to let dead fish lie and tell the client you have an official engineers sign off, you have someone to sue if it fails, cracks leaks? I maintain I want it reinforced and call me over conservative?

Last question. I'm having a hell of a time here. I'm thinking the moment of an out of plumb wall with the top tilted outward would add to the moment of the exterior soil pressure? Am I thinking wrong? The other engineer things the opposite.

 

[nonplussed]

Assuming the wall is braced at the top and not cantilevered, the only real difference the out of plumb will make is the extra moment created by the vertical load times eccentricity. I doubt a 10" reinforced concrete wall would have any trouble with this but it is simple to check nonetheless. My question would be if the wall was actually built out of plumb or whether it's rotated over time. But if another engineer is signing it off then it makes no difference and I wouldn't worry about it.

As for the what to tell the buyer, in my opinion this has nothing to do with you. How much does the value of the house change? Ask a real estate agent, not an engineer. You're only concern is the safety of the occupants (and your liability should something go wrong), and if you or another engineer say the wall is safe then your job is done.