We once had a fellow real estate investor ask:
“I have a crack going horizontally straight across the basement wall at one of my properties. I am assuming it is a result of hydro-static pressure. I have had the drains snaked and the tenant does a decent job of keeping the gutters clean. I have also tried to change the gradient so the slope moves water away from the house. The crack has not gotten larger for over a year, but now it has grown. I am concerned this could lead to a structural defect and safety issue. Are my concerns valid? If so, have you had any experience with this issue you would be willing to share?”
This was our response:
This is a common issue in many Columbus, OH basements. Block basement walls built from about 1940 through 1980 commonly have some level of this problem.
The clayey soil adjacent to the basement walls compacts and settles over time as it is saturated with water. This clayey soil applies an increasing lateral force on the outside of the basement wall. Granular soil such as gravel does not behave this way (It drains the water away and does not compact over time). All new construction (hopefully) back-fills with granular soil around the basement wall. Additionally, properly installed exterior foundation drains using high quality and durable piping can ensure that any water “pore pressure” that develops next to the basement wall is drained away for several decades.
There are 3 common “low cost” repair methods that are used on basement walls (see below for the “proper” albeit expensive repair):
Wall plates with soil tieback anchors. This technique buries “anchors” in the soil about 12 feet from the basement wall and then use metal rods to connect the anchor to large plates bolted on the inside of the basement wall about every 6 feet. Expect to pay $700 to $1,200 per anchor.
Vertical steel beam method. Typically, beams are installed every 4 feet and cost about $450 per beam. This technique is decent, as the steel beams can be “buried” into the basement floor concrete slab and secured to the first floor framing system. These connections at the top and bottom of the vertical steel beam provide shear strength to the wall that the other two “low cost” repair methods don’t.
Fiberglass Reinforced Strips applied to the interior of the basement wall. Not sure on exact cost, likely similar to the other methods above, but this option really is not useful if your cracks are more than about 1/8” wide.
These repairs usually cost around $10,000 to do all the walls in a basement.
These repairs only partially strengthen the wall though, they do not fix the underlying (soil) and drainage problem. Although the wall’s usually need strengthened either way. The construction industry either did not understand this problem well in the 40’s through 80’s or were trying to stay low cost and they subsequently built masonry block basement walls with little to no steel reinforcement and corresponding block grouting to strengthen the walls. These wall strengthening efforts, which are fairly simple to implement during construction, would have likely provided enough strength to the basement walls to resist (not crack) under the worst of saturated (poorly drained) clay soil.
If you don’t have water coming through the walls I would continue to monitor the crack size each year. Each wet/dry cycle of the seasons could increase the crack size. Doing the things you mentioned is the proper way to keep the water out of this clayey (non-ideal) soil (which keeps the pressure on the wall to a minimum). If the cracks grow more than a 1/16” a year I would consider making some sort of repair.
The correct way to repair this problem is to completely remove bowed sections of basement block wall and re-build them stronger (grouted steel reinforcement inside the block), then install new exterior drainage piping, and then backfill on the exterior with granular soil. If you are going to go through this trouble, it is worth installing a solid, well built and well designed drainage system around the exterior perimeter of the basement wall.
If you are looking for a property management team that has several decades of experience dealing with nothing but property management including the issues described above, do not hesitate to reach out to RL Property Management Group. Contact Us Here.
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