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Grip-Tite foundation systems

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SLTA

SLTA

Structural
Aug 11, 2008
1,641
Anybody on here ever use Grip-Tite Foundation Systems for basement repairs? It was recommended in an old report I read, and I have some thoughts, but I'd like to hear yours...

 
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I dislike any system that puts new structure through to the far (soil side) of the wall, and have never used or specified one. I just don't buy their lonbg term durability, and they seem destined to be hit by some future owner digging porch footings, as well as an unpredictable variable for seismic.

I'll be well keen to see others' thoughts on this one!
 
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SLTA:
Do they have ICC-ES reports on any of their products? Which ones are you planning on using? Get all of their literature and test reports, and study them. Also, do they have installer training and a certification program and proof of same? What are the local soil conditions w.r.t. their product’s usage, and do these represent a significant corrosion issue? While they may not be a perfect solution, in all respects, they probably provide a preventive solution to the walls caving in or the foundations failing; and are likely less expensive, although not better, than new walls.
 
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I wasn't planning to use it; I read about it in another engineer's report and it seemed wonky to me. I was hired to come behind them and check the stability of the repair that did happen, which was totally different than what was recommended. Nice, huh? Thanks for your thoughts, folks.

Seems to me that just prying a wall back into place doesn't do much but put additional stress on those small sections of the walls that are getting pulled. Nowhere in the report was there talk of remediating the cause of the problem (in this case, lots and lots of water). Just odd.
 
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Given those circumstances, that's a crap report. Make that "another". *sigh*
 
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I used Grip-Tite anchors on two projects some years ago. One project was to anchor a basement wall that had moved. The other was to stabilize a low retaining wall that was also moving. I guess they worked because I never heard back from the contractor or property owners.

In my opinion, there are other types of anchors that are easier to use and have higher capacity. With Grip-Tite anchors, you are limited in how deep you can install the anchor plates. In addition, you must be able to drill a straight hole in order for the tendon to hit the anchor hole.

 
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I have never specified or recommended them. I see them at the time of property sale. Usually an underwriter sees this system and raises the red flag to the bank about structural issues. In theory, I guess they would work. My issue is that I usually see these install in unreinforced block walls. Usually there is significant cracking and little bond left in the mortar joints. So the anchor plate engages one or two blocks only. Usually this system is advertised as an advantage to digging along the foundation (which would help solve the problem).

In addition to the questionable engineering, if you read the warranty, they back there product for replacement cost only. They do not cover loss of belongings or structural damage if the system fails. Basically, they install these things and as long as the anchor is stringer than unreinforced cracked block, they are off the hook.
 
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The anchor rods are not long enough to get outside the probable failure plane.
 
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I specify horizontal helical piers occasionally for basement wall repair when other methods are not practical. I generally have them add a horizontal C channel across the wall to distribute the point loads. They seem to work fine. Installers around here give a lifetime warranty on their performance. Well, the lifetime of their business, anyhow.
 
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Excel: horizontal channels? I'd have thought vertical. Or do you stagger the ties vertically? Or both?
 
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I only use one channel and install is about 1/2 to 2/3 up from the slab depending on the backfill height and wall condition.
Cheaper than doing vertical ones and calcs out more effective (most of the time). The ties are usually 5 ft apart and the channel is usually and MC6x18 so it has the stiffness to span 5 ft.
 
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I see what you're doing the Excel, effectively you're bringing the prop from the floor up higher using these anchors... Nice idea, even though I still distrust/dislike/don't think I'll specify any fat side solutions.
 
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Point in fact, wouldn't Excel's channel trick also solve Ron's failure plane concern? The effective wedge down to slab would have the anchoring well out and past the worst case theoretical failure plane if the channel were installed at just 1/3 wall height above the (top, middle, bottom - personal professional judgement, specific circumstances and design practice guides that one) of the slab. The wall is also significantly reinforced as the square of the vertical span is a fraction of the previous design span.

I may just have to give this one further consideration in future...
 
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My concern with using only one channel horizontally is that then you're holding tight the one area that's likely separated most from its neighbors. Those blocks are likely no longer effectively connected to the other blocks, so it's like pulling one or two rows back with the others still being pushed away.

I want to think about it some more.
 
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It is situation dependent, of course. If there is lateral displacement of the block, I will switch to vertical channels. If I can get a good connection to the floor diaphragm, I wont use the anchors all and simply use soldier beams or carbon fiber strips. Sometimes even 2x8 or 2x10 stud walls to brace it.
 
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There is no question that the solution has to match the issue. As with SLTA's concerns, I wouldn't be using any type of anchoring for a visibly failed wall; New wall is pretty much the only choice.

Spraycrete on WWM reinforcement has been my go-to solution for inside the failed block wall. Treated timber wall has been my solution of choice for clients who refuse the cost of the new concrete... I dislike doing it, however, and always require that the client put in far side improvements (hard topping, extended eves trough discharge, correct grade to run away from the house, etc). If the damn timber were ever to rot, the wall may actually finally collapse.
 
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Putting in the horizontal channel doesn't change the failure wedge. The wedge starts at the bottom of the cut (i.e. the floor). If the helical doesn't get beyond the failure plane that starts at the bottom of the wall it isn't doing any good.

Don't get me wrong on the idea of helicals and the horizontal channel. I think it works just fine, although I use (2) channels with the anchor in between.
 
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It may not change the failure wedge, but at only 1/3 height of the wall, it would be hard to imagine it does not make it out and past the wedge into otherwise unaffected soil...
 
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