Advice on bowed wall repair

[bluehen]

Hi. I recently discovered a bow of up to 1.5" in our block foundation wall. I have monitored it for the past year and it is not moving any more, but we are selling the house soon and I want to know how to address it. I also discovered that the bottom block has sheared off and is displaced horizontally by about 0.75" in the worst spot (it appears intact in most of the other places). The bow extends for about a 15' span and is straight on either side of this. Is carbon fiber an option in this case due to the shear at the bottom of the wall? Any ballpark figure as to how much this may set me back or how I should address this issue given our intention to sell in the next year or so? Thanks for any insight.

BlueHen

[TJ1962]

Thank you for your question.

According to the ACI (American Concrete Institure) Structural tolerance in bowing is 1" per 40 lineal ft. This is with a 2" safety factor. Which means that the wall in question is considered within tolerance.

However, the shear slide negates this standard. The suggested repair would be to pin the bottom course of blocks then installation of carbon fiber reinforcement. The average installation cost of carbon fiber straps are $400.00 per strap installed 4 ft on center.

[bluehen]

TJ1962 - Thanks for your response and the information. What does it mean to "pin" the bottom course of blocks? Also, are steel I-beams any cheaper than the carbon? Any reason to choose one over another? Thanks so much for your advice.

BlueHen

[TJ1962]

Pinning the second course of blocks to the first is adding a 1 ft piece of rebar and grouting with concrete for the shear movement.

Carbon Fiber installed with pinning as above should cost about the same installation as installing steel I-Beams.

If you are going to finish the basement walls, steel beams will work fine although lose you square footage. If you are not finishing basement carbon fiber is more low profile and will not be a "red flag" on the value of the property. Both will do the job. Hope this answers your question.

TJ