I have recently purchased a home with a concrete block foundation. The house is built on a slope of about 15 degrees. The wall has a 2-3 inch bow in the center of the wall. I had a foundation company tell me that I would need 8 wall anchors (WallLock) to secure this. Can anyone tell me if these are a good solution? Should I hire a registered structural engineer? What about resale?
Thanks
Replies
I have about 4 or 5 grip-tite wall anchors in one of my basement walls.
For the price and for my situation, it was money well spent. However, my wall was only out about 5/8" in the center.
The walls have gotten somewhat more straight in the 2-3 yrs. i have had them. I may have gotten about 1/2 the bow out or so. More importantly, they havent gotten worse.
I think in order to get yours closer to fully plumb is to have them excavate around the area prior to installation. This will allow them to crank the walls closer to plumb.
For me, in Indiana, I have to wait until June, July, August and September to crank on the bolts to tighten the anchors due to spring rains and expansive clay soil.
you may want to see if there is a grip-tite installer in your area. Go to http://www.griptite.com to check.
Good luck and hope this helps
Find out the cost difference between wall anchors and a new wall. The cost of the new wall would be less if you do not remove the old wall. If a new wall 1 foot thick was poured in front of the old, it would cover, secure and hide the old wall.
"Should I hire a registered structural engineer?"
Absolutely.
Do you know that bearing capacity of the soil that the anchors will go into? If it is moving with the wall it won't do you anygood.
And do you know what caused the problem in the first place? And what is being done to fix it?
If you go to http://www.jlconline.com then Research and look in the back articles. Within the last 3-4 years they had an article on doing this with anchors and another one with butressing I-beams.
IIRC one of the articles mentioned the limits on how far you can fix a block wall without rebuilding it.
"What about resale?"
A friend of mine is a real estate agent and bought a house with 4" pushin in the poured foundation and a horizontal crack. It has all be fixed with an epoxy seal and I-beam suports.
With the engineers documentation of the repairs she does not thing that there will be any problems when she goes to sell.
Georgia is red clay and I believe that run off problems must have contributed to the problem. I have a registered structral engineer coming out next week. I'll see what he says but He seems to lean towards bracing the wall inside with steel. I'll get him to draw up the plans and stamp them and then certify the work after. That should help with the resale.
My friends house also had a hillside behind it and water runoff was the problem. In her case it appeared that the water log ground also froze.Previous owners had done all kinds of work with inside drain system, but never fixed the primary problem.Grading, mudjacking up a patio that also tilted towards the house, and fixing the gutter downspouts and directing the water away and the basement is perfectly dry. And no more movement.
This is something we're doing on a current project. The wall itself has a 2" bow in the middle. House was built in the 20's, so no wall wire or grouted cells. It's not pretty, but the engineer says it'll keep it from settling any more.
I am not familiar with wall anchors, but from what I've seen, they are nicer looking than what we're doing. In any case, you definitely want to talk to an engineer.
As far as resale goes; as a buyer, I'd be happy to see that the problem had been addressed.
Mike - Nice sketches - what that in?
Forrest
Forrest,They were modeled in SketchUp. Great tool.Mike
Mike are these braces custom fabricated? What size steel? It looks like your bolting to footing. I'n not sure I have a footing ;-) would this work bolting to slab?
Yes, the braces were a custom job. I don't have the engineer's drawing in front of me, but if I remember, they were 3.5x5x3/16 tube steel, with 2.5x3.5x.25 angle welded at the top. They are through bolted with 3/4" bolts at the top, and bolted to the footing with 5/8" threaded rod in rockite. Concrete is then poured around the base. Columns are held off of the CMU by an inch or so, and the space between is to be filled with non-shrink grout, which is gonna' be a real PITA!According to my engineer (who always overkills), burying the bases in concrete gives a lot more resistance to pushout....duh. I'd guess that whether or not that was really needed would depend on the loads in your particular case. I might SWAG on my own place, but not for a client. :-)Hope that helped.Mike
In the case of my friends it was much like that shown in the JLC article.There is no bolting, the bottom is trapped in the concrete floor. It was chipped out the beam set and then patched.The top is held by cross blocking with lots of 16 penny nails.I don't remember the size of the beam. Put after it was done there was a basement "shower" that consists of a concrete block walls and a floor drain that was demo'd. Those help buttress the foundation and exposed some ofthe crack that had not be grouted.The person that did the grouting was came back and did that. And I duplicated the other beams.I don't remember the size, but in this case it was a "light weight" beam and I had problem finding one. IIRC it was an S-shape rather an a w-shape.Interestingly it was the same size as used by the person in the JLC article. And he is in the same area. But he did not do the orginal and I think different engineers also.
Yes, I would hire an engineer. However, you might look into pouring a new footing and using shot- crete instead of pouring a new wall. the shot crete will give you 5000psi wall strength and cut down on labor costs.