Replacing Lift - What to do with old holes?
- Thread starter gte610v
- Start date
Diesel Dan
Well-known member
Drive the old studs through the slab, if possible, so they are about 1" down. Fill hole with s-mortar or non shrinking grout.
If they are bottomed out cut flush with floor.
If they are bottomed out cut flush with floor.
lakeroadster
Well-known member
Define semi-close?
The correct answer is to check with the manufacturer of the new lift you are installing... follow their specifications.
How far off is the new bolt pattern?
What kind of anchors were in the old holes?
If the new holes overlap, and the old anchors are a "wedge" type, I might look to see if I could replace them with a "drop in" or epoxy type anchor that was bigger enough around that I could grind the holes to fit.
Anything more than half a hole off though, and that likely won't work.
I'm no engineer, but I might risk that.
What kind of anchors were in the old holes?
If the new holes overlap, and the old anchors are a "wedge" type, I might look to see if I could replace them with a "drop in" or epoxy type anchor that was bigger enough around that I could grind the holes to fit.
Anything more than half a hole off though, and that likely won't work.
I'm no engineer, but I might risk that.
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Warrenator
Well-known member
In my wife's old factory there were quite a few semi-protruding sawed off bolts sticking up through the concrete from old equipment casually removed. I used a zip disc on a 4 1/2" grinder to cut them off flush. They become just a spot in the concrete after a while, you don't notice them.
8man
Well-known member
Stress on the concrete from a 2 post lift is different than with a 4 post lift.
4 post, do as advised above.
2 post lift, contact the factory for advice. You may need to cut out, retie steel and re-pour, that is a safety measure that may be required.
4 post, do as advised above.
2 post lift, contact the factory for advice. You may need to cut out, retie steel and re-pour, that is a safety measure that may be required.
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Sell 'em on eBay - "Lift Installation Kit" 
......Acme brand, of course
edit --- I just read the posts. I'd assumed the hole in question was a big one for an in-floor lift. For those little bolt holes, don't bother. They wouldn't bring enough to be worth the shipping.
......Acme brand, of course
edit --- I just read the posts. I'd assumed the hole in question was a big one for an in-floor lift. For those little bolt holes, don't bother. They wouldn't bring enough to be worth the shipping.
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rattle_snake
Well-known member
Most concrete anchors have tension spec (the one you care about) de-rated when installed in proximity to an edge, crack or another hole. The specs and de-rating are published by the anchor manufacturer, so this is what you need to determine your situation.
Typical mechanical (wedge, drop in , screw in) need about 12" from anything. However the spacing between the anchors themselves in the base plate is less than that, more like 6". So the 'critical distance' from any new hole to an old hole is roughly equal to the bolt to bolt spacing of the baseplate.
If you want the new 2 post lift post in the same location as the old, you will most likely need to re-pour. It doesn't matter what you do with the old holes, the concrete is already compromised.
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lakeroadster
Well-known member
Edge distance, for a Rotary 2 post, is specifed as 4-1/2", using Hilti Kwik Bolt III's: http://www.rotarylift.com/Support/FAQ/.
But epoxy anchors are more forgiving. They don't stress the concrete like mechanical anchors and they require no minimum nut torque, since they are chemically bonded to the concrete and don;t require nut pre-load to lock the anchor.
The OEM of the lift may well recommend epoxy anchored studs if the new holes are indeed in close proximity to the new holes.
I wanted to use epoxy on my Rotary, and called the factory. They supplied the specification via email.