Basement HELP!!!

My wife and I are considering buying a house. The ONLY thing wrong with it is a horizontal crack in one of the basement walls. The wall is bowed out about 3/4 of an inch, just barely noticeable. The basement is completely dry and in extremely good shape otherwise. The house was built in the 50's, and i was wondering if this was simply a sign of its age, or something I should really be worried about.

 

A vertical crack would suggest a settling of the house, which in most cases you can live with, but a horizontal crack along the length of the wall would suggest outside pressure on the foundation wall. (1) Check the thickness of the wall. (2) Find out if any construction was done (below ground) on the property. (3)
If you really like the house do a little P.I. work, ask neighbors, etc.

 

You should be very concerned about a horizontal crack in the block; it's most likely pressure from the earth outside pushing against an under-designed wall as Undercover said. That is normally repairable; a friend of mine had this problem on his house and it was fixed by a series of short stub walls perpendicular to the block walls.

If you really like the house, you need to have a structural engineer look at it. This is something that should not be left as is. Quite a number of years ago we had just the right weather conditions in this area and there were a lot of basement walls that collapsed.

Bruce

 

We are having the same problem with a Cabin we bought in Northern WI. Maybe someone can voice an opinion on this idea. We were going to lay a row of concrete block 8 inches to the inside of the bowing foundation wall. Brick it upto the floor joists. Then backfill the 8 inch space between the existing wall and the new block wall with concrete.

Any ideas?

 

To make sure I understand what you are saying: You are laying a new 8" block wall parallel to the existing wall and 8" away, then filling the space between with concrete.

I am not an engineer, but am not sure if this will work. The problem with concrete and masonry is that it has relatively poor strength when it is in tension (which this will be) unless reinforcing is added on the side that is in tension. The reason the wall is failing is probably that reinforcing was not added in the first place. Code requires steel in block walls for most basements, but the fact is it seldom gets done and inspectors generally ignore it. Usually it works without, but occaisionally it doesn't.

When my friend got his fixed, the solution was a treated wood stud wall with plywood both sides and anchored at the concrete floor and at the floor joists above. We don't remember any of the details and he since sold the house. I would really encourage you to get a structural engineer to look at it.

Hope this was at least some help to you; sometimes if someone asks me what time it is, I tend to tell them how a watch works!!

Bruce

 

Oops! Forgot to mention that the wood walls were stub walls perpendicular to the masonry wall as I indicated in my previous post.

Bruce

 

After giving it some though, I had the same concerns. There is no lateral support other than the weak tensile strength of the concrete. Here's the new idea. Build a treated stud wall with plywood facing into the center of the room, 8-10 inches from the existing wall. Create rebar/steel supports. Brace the heck out of it and poor the concrete wall between the stud wall and the existing wall. Here's my new question. The existing wall has cracks and water penitrates in during the spring. If I apply a tar (don't really what it is made out of but it's black) water barrier on the inside of the existing wall before I poor the new concrete, will this prevent water from penitrating to the new wall. Or does anyone have any ideas of how to create a water barrier from the existing cracked foundation wall and the new concrete wall.

Thanks for the responses.

 

What you suggest may work; be sure you bolt it really well to the existing wall, floor and joists above. Not sure why you want to pour a wall in front; appearance? waterproofing? I hate to keep harping of this, but I really think a local engineer ought to look at this. I know its more money, but it could end up looking cheap if what you finally put in doesn't work.

As to waterproofing, putting the waterproofing on the interior side of a wall only sometimes works. The problem is that the hydrostatic pressure of the water wants to push the waterproofing off the interior surface. Also be aware that these materials are generally called "dampproofing", which means that a small amount of water could weep through it (not designed to stop a large amount of water).

I always tell my clients to try the cheapest solution first: do you have a good slope away from the building outside? Should be something on the order of 1" per foot for 8'. If not, then add dirt and see how it works. Next step would be the waterproofing on the interior. Be sure the wall is braced so it won't move any more; the waterproof materials generally can't tolerate any movement. Beyond that is a lot of work/money.

Hope this helps.

Bruce

 

Im not sure if your referring to a block wall or poured concrete.

In any case a horizontal crack is serious. First you need to do some engineering takeoffs to determine the problem.


This will show you where you are. it may involve a simple piering solution? Hope this helps.
JoeW