Hello, I am new to the forums and I look forward to learning from you. My wife and I are planning to purchase a house but its retaining wall is a major obstacle at this point. We know that another buyer had put in an offer but later walked away due to the retaining wall issue. Here are some details.
The walls are in the driveway leading to the garage. Below is the general view. There is what I call “Wall A” and “Wall B”. The more problematic wall is Wall A.
http://www.andrew.cmu.edu/user/lkara/personal/houses/hassinger/ISly80wg3zdvaq0000000000.jpg
Here are pictures of Wall A:
http://www.andrew.cmu.edu/user/lkara/personal/houses/hassinger/IMG_0247.JPG
http://www.andrew.cmu.edu/user/lkara/personal/houses/hassinger/IMG_0248.JPG
http://www.andrew.cmu.edu/user/lkara/personal/houses/hassinger/IMG_0249.JPG
Here are pictures of Wall B. This wall has started to lean, but it has not cracked yet:
http://www.andrew.cmu.edu/user/lkara/personal/houses/hassinger/IMG_0245.JPG
http://www.andrew.cmu.edu/user/lkara/personal/houses/hassinger/IMG_0246.JPG
The original contractor ‘guarantees’ that (in writing) these walls will not fail inward! Well, that’s kind of obvious! The issue is that the walls are failing outwards. The contractor has installed the support rods (the diamonds in the pictures) and from time to time they agree to come over to tighten these rods. However, the contractor will not fix the cracks or redo the walls.
My question is whether these two walls can be redone from scratch in a way that they will last for decades without failing. If so, roughly how much would this cost us? This is in western PA.
If my inquiry is missing any details, I would be happy to provide them. My wife is quite excited about this, but I am very concerned about this retaining wall issue.
Thanks in advance.
Replies
The walls aren't "fixable"
The walls aren't "fixable" without major work. Wall B probably will hold up for a long time without deteriorating much, but wall A will continue to deteriorate.
The best "fix" is to take them down all the way to the base and rebuild, this time properly counterweighting them, either by leaning them in or by placing anchor pieces ("deadmen"? I can't remember the term for sure) in the soil behind them. I would plan on doing this fairly soon (within a couple of years) for A, but B can probably wait until it gets worse.
Thank you Dan. I appreciate your input. So if we decide to take it all down and rebuild Wall A, do you know roughly how much it would cost given the height of the wall? I know this is probably very difficult to estimate, but I have no point of reference. I can get quotes from contractors here but an objective assessment (even if it is rough) would be most useful.
Also, the deadmen anchors you mentioned, these are not the diamonds seen in the pictures, is this correct? I don't know the name for those diamonds but if I am not mistaken structural rods extend from them into the soil and you can tighten them through the diamonds? I am very new to these construction field so any input would be much appreciated.
The "deadman" is a member
The "deadman" is a member running back from the wall -- this image is of wood but it can be any material:
View Image
The steel rods are a form of deadman -- I don't know how effective vs solid members.
This image shows another critical point, drainage:
View Image
As to cost, about all I can say is thousands, but probably not much over $10K. A lot will depend on the materials used and how fancy you want it. And do note that any wall that high is non-trivial, and may require permitting and an engineer's stamp (which may run a couple of thousand on its own). Generally walls over about 3 feet require special attention.
Wall A is not only beyond repair, but it appears to currently be a significant safety hazard on your lot. I would hire someone to demolish the top part (at least the leaning and distended elements projecting out into the driveway plane) down to a safe height ASAP.
Yes; certainly this particular wall confiquration can be built to last a long time if done correctly. As Dan intimated, the lateral forces on this wall are significant; particularly given that it is built as a convex curve. Hire an engineer to design it correctly and a professional contractor that has experience with this type of structural masonry work. It will involve a large amount of excavation work and site work (in addition to the masonry) if done correctly. It's not a handyman or DIY project. Be prepared to pay handsomely.
get an engineer
You can certainly wing this with the promises of a contractor who thinks they can rig it, but the wall is failing because of a likely range of factors that proper design would have prevented.
I am going to build a retaining wall 14 feet off my house, on a slope with a 5' drop from basement floor to lower grade, and the wall will be 30" above grrade (so part of the slope will remain). I needed an engineer, who needed a soil test. The soil (expansive clay fill with natural grade at the foot of the slope) was crap, and had a coefficient of friction that was really low. So for a 30" high CMU wall, the footing is 54" wide and 18" thick, so there was sufficient weight to prevent slide and tipping. Overkill? Not given the #s from the soil report. The $1,000 I spent for the engineer and $1700 for the soil tests will yield a wall that won't move.
What you need to find out is whether the wall is failing because the upper portion was compromised by an insuffucient footing; or the lower portion of the wall is stable but the upper part was insufficiently tied in and can't resist the lateral forces of the soil/hydro pressures, or the wall is largely intact and someone added a number of courses of brick that are failing. The cost of repair will be determined by where the failure is actually present. Like deadnuts said, you need an engineer to determine that. And that engineer will most certainly require a soil analysis to get real data about what is going on.
Thank you very much all for this info. I think my fears are confirmed. We could factor the hefty reuild price into our offer, but all the unknowns really make me uneasy. Finding the right engineer, getting the right contractor, monitoring the construction...
I don't have a good network of engineers or contractors around here. If you were in my situation, what is the best way to start finding capable engineers/contractors in my area? I can't think of a good way except for hours of web search (and much needed education) or referrals through friends.
Thanks again very much for your input, it's very useful.
my way
find the best contractors and ask them for their collaborators (engineer, a masonry/concrete company, maybe a full spectrum landscape contractor who can do hardscape like this). I have a meticulous high-end contractor friend and his collaborators are all great; his reputation is as much based on their work as what he does.