This is a picture (click on image to enlarge) of a wall anchor and a Fortress carbon fiber grid strap. The reason both repair products are in this picture is that the wall anchors weren’t working very well and wall movement needed to be stopped. With a wet rainy spring last year the wall anchors had slipped inward through the wet clay soil. The wall had continued to bow inward in between the monthly required tightening maintenance on the anchor plates. The other problem was that the wall anchors had done nothing to prevent the bottom of the wall from shearing at the second from bottom block and sliding inward on two out of three walls. We removed the anchor plates long enough to install Fortress carbon fiber grids and then reinstalled the plates for a day until the carbon epoxy had fully cured.
The wall anchors are really better suited for installations on solid poured concrete walls. When these anchors are installed on cement block walls you are only addressing wall movement around the immediate area of the wall plate…four or five blocks, not stabilization of the top or bottom of the wall. There should not only be concerns with the wall shearing at the bottom block but concerns with punching shear, where the block actually snaps and breaks around the anchor plate when the anchor doesn’t slip. These are all problems related to “point loading”, which is anchoring a small amount of surface area on a wall in an attempt to stop the inward movement. When hydrostatic soil pressure is a major factor related to your inward wall movement you really need to give your choice of wall stabilization more consideration. You can even point load your wall when you install large “sheets” of carbon fiber fabric. Unless the fabric installations extend the full height of your wall… you are not addressing the area of the wall which has the highest amount of pressure on it…the very bottom of the wall where the second block up is not locked in by the floor, and you are not address the possibility of freeze break near the top of the wall. Because in this case the wall had sheared in several areas we had to compliment the carbon fiber installation with a rod and grout repair at the bottom of the wall in certain areas.
We suggest you do your homework before you spend your hard earned money. Ask tougher questions of the nice folks who come out to see you and see what kind of answers you get. If you know what kind of questions to ask and what to look for… it will be much more obvious which contractor you want making your repairs. It will be time and money well spent.
Jim: P.S. here’s another great site to learn more: www.basementquestions.com check them out when you’re done with us!