Struc­tur­al Foun­da­tion Repair — Car­bon Fiber vs. Wall Anchors

Dec 27, 2012 • By Matthew Stock.

When there are cracks in a home’s foun­da­tion walls, some­thing is wrong.

Not every foun­da­tion wall crack is struc­tur­al; most nar­row cracks won’t affect the integri­ty of the foun­da­tion but they can allow seep­age. These cracks can be repaired per­ma­nent­ly by hav­ing a base­ment water­proof­ing com­pa­ny inject them with expand­ing polyurethane.

How­ev­er, if the cracks are wide (more than 1/8”) they may be allow­ing the foun­da­tion wall to move inward – poured con­crete walls rotate in from the top; con­crete block or oth­er mason­ry walls bow or bulge in the cen­ter. This is a much more seri­ous prob­lem but it can be repaired.

Two Repair Meth­ods for Struc­tur­al Foun­da­tion Dam­age: Car­bon Fiber vs. Wall Anchors

Car­bon Fiber – Car­bon fiber repair is the state-of-the-art method for fix­ing struc­tur­al foun­da­tion dam­age. Woven car­bon fiber strips are applied ver­ti­cal­ly to the dam­aged wall, with place­ment deter­mined by the pat­tern and direc­tion of the cracks. The spot for each strip is ground smooth to ensure adhe­sion, a super-strong epoxy is applied and the strip is set into the epoxy under pres­sure. A steel angle is affixed to the top of the foun­da­tion wall to pre­vent fur­ther inward move­ment and the wall is per­ma­nent­ly stabilized. 

Wall Anchors – Wall anchors are a more tra­di­tion­al method of foun­da­tion wall repair. A hole sev­er­al feet deep is dug in sta­ble soil approx­i­mate­ly 10’ from the foun­da­tion. A thread­ed rod is then dri­ven through the foun­da­tion wall from inside so it emerges in the hole in the ground. A heavy-duty steel plate is set in the hole and the end of the rod is affixed to it; a sim­i­lar, lighter plate is placed on the inside. The rod is then tight­ened, which pulls the wall back into plumb and clos­es the cracks. The out­side hole is filled and com­pact­ed. The num­ber of anchors required is deter­mined by the size and con­di­tion of the wall and oth­er factors.

Which Struc­tur­al Foun­da­tion Repair Method is Bet­ter, Car­bon Fiber or Wall Anchors?

Car­bon Fiber – Car­bon fiber repair is incred­i­bly strong, requires no exca­va­tion and caus­es very lit­tle dis­rup­tion of the base­ment. When installed with a steel angle at the top of the wall, it com­plete­ly sta­bi­lizes the foun­da­tion. Also, the com­plet­ed repair cre­ates only small bump on the wall and can be paint­ed or fin­ished over with a nor­mal stud wall. Car­bon fiber repair requires no main­te­nance; its only lim­i­ta­tion is that it can be used only when a wall has moved inward two inch­es or less.

Wall Anchors – Wall anchors can be used no mat­ter how much a wall has moved inward and they do actu­al­ly straight­en the wall when sta­bi­liz­ing it. How­ev­er, that sta­bil­i­ty relies heav­i­ly on the con­di­tion of the soil where the anchor plate has been set. If there is fur­ther move­ment, swelling or des­ic­ca­tion in that area, the wall can de-sta­bi­lize. Also, it is much hard­er to achieve prop­er yard drainage, as mov­ing water from down­spouts and sump pump dis­charges the nor­mal ten feet away from the foun­da­tion will over-sat­u­rate the soil where the anchor is buried. Final­ly, wall anchors require peri­od­ic tight­en­ing by the home­own­er to main­tain sta­bil­i­ty so a fin­ished wall can­not be erect­ed over them.

So, which one is the best? Car­bon fiber has the edge most of the time because of its ease of instal­la­tion, per­ma­nence, unob­tru­sive appear­ance and free­dom from main­te­nance. When a wall is bad­ly dam­aged, result­ing in inward move­ment of sev­er­al inch­es, the two process­es may be com­bined, with sev­er­al wall anchors pulling the wall back into posi­tion and a num­ber of car­bon fiber strips pro­vid­ing per­ma­nent sta­bil­i­ty. The key is employ­ing the exper­tise to rec­om­mend the best, most cost-effec­tive per­ma­nent repair that ensures the safe­ty of your home and the use of your basement. 

At U.S. Water­proof­ing, we are experts at installing car­bon fiber struc­tur­al foun­da­tion repairs but we also know and rec­om­mend more tra­di­tion­al approach­es when required. We have prid­ed our­selves on being a full-ser­vice resource to our cus­tomers since our found­ing in 1957, so ask us for a free con­sul­ta­tion if you’re wor­ried about your foundation.

Tags: foundation cracks, foundation damage, foundation repairs, structural foundation damage, house foundation repair, home foundation repair, structural foundation repair, carbon fiber foundation repair, foundation wall anchor

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