The retaining wall on the side of my driveway leans a little. Always has (it’s from 1952, we bought the house in 2001). Last week I noticed some cracks at the base of the wall, so I had a couple masons in to look at it.
One guy told me he could patch it up for about $375 and that it would last another year or two. Possibly more if the next winters were more mild and if we removed the bushes growing behind the wall.
Another guy told me that it could go over any day; that I could probably push it over with my hands; and that it should be fixed immediately.
My question is this: Is there much risk in taking the cheaper solution and waiting to see what will happen? Will the wall spontaneously give out without warning, endangering whoever might be standing in front of it? Or are there signs of imminent collapse? If so, what are they? (I think the second guy was bullsh*tting me a little bit.)
If the wall does go and I call somebody in to fix it, will it be more expensive? Is there some cheap way to shore up the wall for a year or so until I (hopefully) have more money?
I’m definitely no expert in this field, but I think you may have answered one of your own questions:
I think it would be safe to assume that fixing it now would be less expensive than fixing the damage later. Keep in mind, you’d be fixing a wall now. You might be fixing a wall later, as well as everything it pulls down with it. And that could lead to future structural weaknesses/damages, which means (you guessed it) more money.
I’d say in this case, a stitch in time saves nine. Good luck with that.
Are there any civil engineers in your region (either county, municipal, or private) who would examine the wall without having a vested interest in selling you a repair? (Of course, they might charge $400 just for the survey, but you might get a more accurate assessment.)
Depends. (Dontcha love exact engineering terms?) You don’t say how high the wall is, what it is made out of, or how far it is leaning, so estimating the danger of damage by collapse is difficult. Just the same, if all you’ll get from a repair is a year or two, and the wall is not very high (say 3-4 feet), then forget about it and let it collapse. A proper repair will require pulling the wall down anyway, so why pay to pull it down? In the short term, you don’t need to remove the bushes so much as trim them back to minimize the root growth, and bore some holes at the base of the wall to let water drain. In general, once a retaining wall starts to lean there is nothing much left but to remove it, especially if it is a stone wall. On the plus side, if it is stone, once it is taken down the stone can be cleaned up and reused (Only this time, make sure it is properly built and has drains at the bottom).
Also, tell us which way it’s leaning. If the top is tipping out over the toe, it might be ok. If the toe is bulging out, it’s in danger of imminent failure. I know it doesn’t make intuitive sense, but the pressure of the soil behind the wall is greatest at the toe. Some walls were built leaning out at the top.