Can you place anchors in a concrete slab at a later date?

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We are having a concrete driveway put in next week and we want to put up a 16x16 out building next year. I am having the pad for the building done at the same time as the driveway. For safety reasons I don't want the contractor putting in the threaded anchors for the walls during the pour. How can I install these anchors next year when we are ready to put up the building?
Thanks for any help.
Keith
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Drill holes next year and put in expanding anchors. Not an issue. Or put the anchors in now and just cover them.

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have slab level and perhaps thicker where the anchors will go.
dont put them in now they are a trip hazard. i have some sticking up from a delayed shed addition
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snipped-for-privacy@aol.com wrote:

Put them in with the pour. Set a flower pot on top of each til the time is right.
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On Fri, 14 Jul 2006 11:50:38 GMT, Keith Boeheim

It can be done next year.... just a hell of a lot of work.... !!!!
If you are afraid someone will trip over them... just cover them over with a little sand, soil, etc and next year sweep the sand and soil away... much eaiser.
Bob
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If you really cheap a learned a great trick years ago. If you ever need to tie some 2x4's etc to concrete drill s 5/32 hold through the 2x4 and the concrete drop in a piece of 14 gauge copper wire and then bound in a 3 1/2 nail. IF you don't believe me try is and then try pulling it out. YOU WON'T WITHOUT BREAKING THE NAIL.... The copper expands into the concrete and it stays there...

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I've done it both ways and I recommend putting in the anchors now and covering it for the year. It's much easier and much better.
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Hilti makes products for this that drop a capsule of epoxy into a drilled hole to bind an anchor, just don't use them to hang the cieling like they did in the Big Dig Keith Boeheim wrote:

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snipped-for-privacy@localnet.com wrote:

Just don't do that the way they did here in Red Sox Nation:
http://tinyurl.com/ovwnb
What a effing mess this is...
Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)
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On Fri, 14 Jul 2006 11:50:38 GMT, Keith Boeheim

Can work both ways. I work for a concrete company and we do it both ways depending on the situation. Just make sure you buy good quality anchor bolts either way.
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I can appreciate the concerns that you have about protruding bolts being a hazard, but a properly concreted-in J bolt is so superior to just about everything else, that for a 16x16 outbuilding I'd strongly recommend installing them now anyway.
Put cinder blocks or flower pots (why not with flowers?! ;-) over/around them or something like that to eliminate the safety/tripping hazard.
If you do choose to install later, research concrete anchoring systems on the net, and follow the instructions of the one you choose _to_the_letter_.
Remember, this isn't a lifting load (w.r.t. the big dig accident a few days ago), so that's not going to happen. But strong winds are perfectly capable of moving structures like this, and just picking up lag screws and anchors out of a hardware store bin _can_ be a mistake if you don't install them properly.
Apropos this, I just repaired a deck railing mounting support that was less than 3 _months_ old, because the alleged "professional handyman" who previously owned the house didn't know that the lag screw is supposed to thread _into_ the anchor, not just push the anchor farther back into the ridiculously deep hole in the masonry.
Seriously.
The hole was so deep that the the lag screw pushed the anchor 4" behind the face of the masonry and didn't engage the anchor _at all_.
He was expecting this nonsense to pass inspection.
Without washers under the lags.
Fixing the anchors involved pulling the lags out (they were loose. Pulled straight out), fishing out the anchors with wire, threading the anchors on just enough to bind in the hole, and then winching up the lags.
Not to mention the 4' long cleated together 2x12 (! what was he holding up? The Queen Mary?) deck support "beam" he was supporting both ends on some pieces of rotting wood lying horizontally on the dirt, when a perfectly adequate masonry post was 6" away from one end, and butted up against masonry on the other. So I did 2 2x6s supported on the post and a 2x4 sleeve-anchored to the wall for the other end, and inspection passed.
What an airhead.
We assume that he sold the house and left town because the work he was being paid to do for others was so obviously and completely half-assed.
--
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
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snipped-for-privacy@nortelnetworks.com (Chris Lewis) wrote:

Actually, it's the lifting forces imparted by high winds that the anchors need to handle.
If the structure is tied together (e.g., with hurricane clips,) then high winds going over the roof will create suction and uplift forces. These must be withstood by the anchors, or the scructure will lift off its foundations. (If the scructure isn't tied together, then the roof will just fly off.)
The other thing that happens is that lateral wind forces on one side of the scructure will tend to push that wall inward, rotating it around the sill plate. This will create a lot of upward force on the anchors, as the wall is essentially a large lever. This can be mitigated somewhat by using sheathing (OSB, plywood, etc.) around the outside of the structure, or at least at the corners, to counteract the racking forces.
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Sorry, should have been clearer. Yes, I've seen the calculations showing many 100's of pounds of uplift per rafter under hurricane situations with relatively "normal" size roofs. I meant that they're not under continuous stress 24x7, holding up tons of concrete - where the slightest imperfections in installation/bad concrete/vibration _may_ work some anchors loose.
That said, I like the other idea, forming a 12" stub wall with anchors (perhaps female thread slugs, not threaded rod) in _that_. The OP would be far happier with the resulting structure.
--
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
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El Barto wrote:

I will note that Steel Frame houses use chemically anchored bolts to attach the steel to the slab. These bolts are installed AFTER the slab has cured. see www.tri-steel.com
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Unless this shed OP is putting in next year is metal, he should lay up or pour a proper foundation stub wall. Even a PT sill plate sitting at slab level is asking for trouble. Yeah, an 8 or 12 inch wall sticking up for a year is a PITA, but less hazardous than J bolts sticking up from a flat slab.
aem sends....
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When I put up my 4 post lift, I had to anchor the posts. It was messy and time consuming, but what I did was; bought high quality 5/8" expanding anchors, drilled with a hammer drill and a new concrete bit & epoxy-ed them in. I started out with Hilti epoxy, but ran out. The Hilti store is ~ 35 miles so I tried Home Depot. They have a 2 part epoxy in a caulking gun tube, that if I were to do it again I would use from the get go. Those last 4 holes were the easiest and the best. None of the anchors ever came loose, and I regularly raise 6000 lb pick-ups and shake them around working on them. I sold my Hilti epoxy gun after finding these glue tubes, highly recommended. Just an after thought, what about sinking threaded inserts into the concrete when it is poured? You could have bolts in them to keep the concrete out of the threads, and remove them after it cured to solve the tripping hazard.
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Best idea I've seen yet. To embellish this use a fairly long threaded bolt, put on several nuts with large washers between each. Install only loose finger tight so they don't bind removing the bolt.
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I couldn't envision what you were saying at first, now I get it, not just yeah, but hell yeah That would be cheap, effective and bullet proof.
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in my town, the local building inspector requires either a j bolt or a 5/8 expansion anchor drilled 7" into the concrete. yeah, it's overkill, but that's what they want. they also make a deal that is basically a piece of rebar with a female threaded end. it can be flush with the top of the pour, and then a piece of threaded rod can be screwed in later.
Eric in North TX wrote:

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This is an interesting thread with a lot of pertinent info for my project. Last week, one of the neigborhood kids was attempting a dive off my diving board when the support bolts broke. No one was hurt but it did create a bit of drama for the afternoon
The diving board mounts with two bolts to a boat-shaped fiberglass base. The base is anchored to the concrete decking with 6 anchors with three at the front of the base and three at the rear. Am not that familiar with these fasteners but they are about 1/2" dia, serrated and pointed. They are plenty rusted and I could barely make out the remnants of what must have been nuts and some yellow plastic caps for these studs. May be these were Ramset type?
Anyhow, I need to fix this and was going to cut them off flush as they only extend about 1" above grade and are not long enough to try and reattach with. The rear bolts will be in tension when the board is in use. Will the regular Home Depot 1/2" anchors would be enough? Reading this thread, perhaps the epoxy might not be a bad idea.
Finally, whats the best method to rust proof these? Krylon paint or ?
TIA Mike in DFW, Texas

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