How To Know If Wall Cracks Are Pointing To Foundation Problems

A friend asks about a new home they just bought. It is a 1950’s home that was built on cement block and the home is in general good condition for its age. Obviously there needs to be a lot of upgrades performed to bring it up to today’s standards but it is livable and most of the upgrades will be performed as time allows and not because they are required.

The problem they are having is that a corner of the home has cracks in the first floor outside wall and some of them are hairline and a couple are significant. One below a window is a good 1/4″ wide at its worst and runs from below the window to the floor. There are additional cracks around that window that run away from it and partly across the ceiling. The floor has also sagged within about 6 feet from the outside wall.

Evaluating cracking is not the final say so but in some cases it will lead you to problems. My first concern would be if there was any remodeling above or below that room. Anyone such as a plumber or a home owner that cut holes in joists to fit pipes may have caused this problem. If it is known that there was remodeling then that needs to be looked at first. If there hasn’t been any remodeling or if the space above this room is sleeping area and not a bathroom then you have less immediate concern of collapse however it still could be pointing to a dangerous situation that needs to be fixed now.

You should start in the basement and inspect the walls of the home. If necessary this means pulling off any drywall or paneling in the area that needs to be inspected. Look for cracking in the walls, walls that are leaning, any separation at the concrete floor slab.

If you are convinced that the block wall is in good condition then move up to the framing. Sills, rim joists and joists can be damaged from moisture. They will eventually break down over a long time but when there is uneven problems like this they are normally damaged from rotting. Take a screwdriver and poke at the wood if it is dry but don’t be extremely aggressive. A good board shouldn’t allow you to poke through it. Inspect the joists for rot or cracks or damage due to a contractor cutting them. One thing you can do is place a straight edge along the edge of the joist and look for warping or sagging. A string line might also be helpful.

If you have not found any problems to this point count yourself as lucky. Next move to the first floor and  inspect both outside and inside the home for water damage. Water can leak all the way down from a hole in your roof through the walls into that area around the window but more likely is problems with the siding and moldings around the window.

If needed you will need to remove drywall around the window to inspect the voids and studs or remove siding on the outside of the home. You are looking for any damage that might cause the cracking and what you may want to do is add studs to that area to stabilize it..

Another problem is the ceiling of the room and this could be caused by the problems we have seen and cured but it could also have been from remodeling. In the case of poor remodeling you will need to build in a support system to carry the load. You will most likely need to add an aditional joist or two to beef up that area to compensate for any holes cut for plumbing. Basically what you are doing is building something like a stairway opening to install stairs to a second floor. You are adding joists to increase the load caring ability of what remains.

Final Note

Cracks in foundations and walls that happen when a home is new are often due to settling and this is normal. You can expect to do a bit of drywall work the first couple years after a home is built. However if an older home has cracks in the drywall in one area of the home that are large and they happen suddenly then it is time to take notice and really hunt down why it is happening.

Normally in older houses especially ones with wood siding you have rot problems. However like said if there was remodeling and maybe by an unlicensed contractor or home owner that caused damage to framing lumber that needs to be addressed immediately.

When in doubt call in someone to help and ask for an evaluation.