Reinforcement of cracked concrete foundation walls...

[mfstructural]

I recently looked at a foundation with several cracks at two of the corners and the ends of the same wall. The house was a "split level" and was constructed in the 1970's. I've included some pictures.

The cracks in the one corner was continuous from one window to the perpendicular wall window, with a vertical crack in the corner as well. the cracks were observed over previously repaired epoxy (presumably over pre-existing cracks).

The crack in other corner originated near the top corner and was diagonal in nature. there were several repaired cracks in this wall, especially at the windows (temp/shrinkage cracks) the cracks were not done by the current homeowner, meaning they were older than 12 years old at a minimum.

An inspection of the outside brick veneer wall at the exterior showed a lot of tuckpointed joints. when i placed a level plumb against the brick, you can see the bottom of the wall and foundation were inwardly displaced. I think it was originally constructed eccentrically, based on the mortar joints observed, but has gotten worse.

A vertical crack in the adjacent wall was also observed. this crack had sharp edges and appeared relatively new.

I'm thinking of reinforcement with vertical WF members anchored to slab and to joists.

I'm looking at repair recommendations. Although the house and foundation are not in danger of immediate collapse, I think the foundation needs to reinforced with vertical members at some point. my question is would you recommend ASAP or monitoring of the foundation for movement and reinforcing if movement continues, which it will at some point based on my observations.

The gutters and sump pump used to discharge adjacent to the house but now they have diverted away from the foundation.

It's very expensive for the homeowner (I know it's not my money), but I want to come up with a balance to save her as much money up front and do some repairs in the future. she is putting the house on the market and this foundation will be an issue during home walk thru's and sale negotiations.

 

[mfstructural]

I just wanted to reply and say that I am recommending to reinforce the affected wall. if it is not done in the near future, the wall should be monitored for future movement and reinforced when movement is noticed.

 

[SLTA]

Where is the house? What kind of soils is it on, or are typical in that area?

Are there gutters at the corners with stupid buried drainlines?

Is that foundation continuously-poured concrete or panels? I'm trying to understand the vertical lines I see in the pics.

I agree reinforcement is necessary - but let's figure out what's causing it all, to make sure the right kind of repairs are made.

Please remember: we're not all guys!

 

[oldestguy]

Are there any trees nearby? Is there a soil map of the area? I'm thinking moisture changes and expansion-shrinkage may be in the picture. Other than the bulging wall what's the problem? Any upstairs cracks or problems? Sometimes living with is the solution. There may have to be a balance between selling it at a good price after major expense or taking a loss and leaving it.

Assuming soil expansion and shrinkage related to moisture the recommendation usually is to stabilize any moisture changes down there. Remove all trees within 30 feet, treat ground surface at house full backfill area to prevent easy water entry. This treatment can be explained and it is somewhat complicated and can be done wrong. Then once done, no significant change to the foundation is needed.

 

[msquared48]

Some thoughts...

Are pictures 6 and 7 the same crack? If so, then subsidence is occurring as well as any lateral movement of the wall.

What does the connection of the floor framing to the top of the wall look like?

Is the sill plate deteriorated? - possibly no anchor bolts? - possibly the joists parallel to the wall with no intermediate blocking?

Any one of the three would compromise lateral support of the top of the wall above, and could structurally force the wall to become a yielding wall rather than a non-yielding (or basement) wall.

Mike McCann, PE, SE (WA)

 

[Tmoose]

How many cracked walls are we looking at?

So there is a diagonal crack on the wall with the gas meter running from low in the basement, up thru the basement window, than thru the brick exterior to the roof line. Held together by cobwebs.

 

[oldestguy]

Here is a possibility. Check the sump at the perimeter drain entry there. The many cracks there look suspicious. If there is considerable sediment in the sump, I have seen a few cases where fine sandy sites lose some support due to erosion of that fine sand via the drain system. Unfortunately architects, builders, plumbers AND MANY ENGINEERS seem to think big voids make a perfect path for water. However, fine sand and silt also tend also to leave the area via the backfill and drains. If the discharge place is such as to allow collecting this material, you might see a delta there.. If this is the case, replace the drain backfill with ASTM C-33 concrete sand. A MORE DIFFICULT JOB WOULD BE ENCLOSING THE GRAVEL BACKFILL ENTIRELY WITH FABRIC.

 

[bridgebuster]

I would monitor it for movement. Has there been some sudden drastic change in conditions since the current owner has been in the house, maybe the nasty looking crack in Photo 6? I've seen a lot of things that should have collapsed years ago but for some unknown reason still stand.

Are there any expansion joints in the brick veneer?