Drilling into concrete floor


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chickenfried
October 18, 2006, 06:09 PM
Going to bolt my safe to the basement floor with Simpson mechanical anchors. I'm a computer geek not a handyman. So I'm wondering if there's anything I need to be careful of? The safe's in a corner right up against the wall. The bottom 2-3 feet of the wall is also concrete. Thanks for the help.

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Taurus 617 CCW
October 18, 2006, 06:14 PM
Just use a hammer drill and a good concrete bit and you will be just fine. Don't forget your dust mask!

Mannlicher
October 18, 2006, 06:15 PM
be sure to wear eye protection if you are going to be drilling into concrete. Helps if you have a 1/2 inch hammer drill and the proper bits.

cuervo
October 18, 2006, 06:34 PM
Only drill as deep as you need to without going through the slab.

Position your vapor barrier where the safe will be.
Set the safe on top of the vapor barrier being careful not to tear the vapor barrier while positioning the safe.
Level the safe with shims.
Remove the floor insulation in the safe.
Wrap a piece of tape around the drill bit at the depth you want to drill. Be sure to include the height of the floor of the safe over the basement floor due to your shims and the thickness of the steel.
Drill until the edge of the tape is level to the floor of the safe.
Use a vacuum cleaner to remove dust from the hole and a pencil to check your depth.

WayneConrad
October 18, 2006, 07:04 PM
If your slab is prestressed or poststressed, drilling into it could pose a very real danger of death and destruction. I don't know if basement floors are ever done like that, but the floors of some ranch houses without basements are, so I thought it's worth mentioning.

Nateyboy
October 18, 2006, 07:07 PM
If you are using Simpson I would suggest their Titan HD's. We use them to anchor our walls to foundations. Just be certain to drill roughly .5-.75" deeper than you need so that the bolt doesn't bottom out. The exceptionally nice thing about these aside from their strength is that they are reusable if you need to remove your safe for any reason.

chickenfried
October 18, 2006, 07:30 PM
Thanks for the advice guys.

What does this mean? It's a home built in the 50's, Is it likely to be prestressed?
If your slab is prestressed or poststressed

Larry Ashcraft
October 18, 2006, 07:37 PM
We used to drill thousands of marble bases every year in the trophy business. If you have a way to pick up water (shop vac), a slow stream of water as you're drilling will make things way easier and cleaner.

Also, there's a HUGE difference in masonry bits from the hardware store and something like a Starrett bit ( http://www.starrett.com/ ), but for only four holes or so, I probably wouldn't invest in one.

WayneConrad
October 18, 2006, 07:44 PM
It's a technique used in slab homes here in Arizona, where the soil tends to be alternatively wet and dry. In post-tensioning, the concrete slab is made with holes in it and steel cable is run through those holes and then put under great tension before being secured. It keeps the slab in one piece when the soil under it is expanding, contracting, moving, and generally being cranky.

I did some more reading and found that it's a fairly recent technique for homes, mostly used in areas like mine, and I *think* in slab homes, not ones with basements. I don't think it's going to be an issue for you. I should have done the research before mentioning it.

It's post first, think twice, right?
Just like cut first, measure twice.

mpmarty
October 18, 2006, 07:47 PM
I would consider bolting into the studs in the wall behind and or beside (if in a corner) the safe rather than into the floor for a number of reasons.

Larry Ashcraft
October 18, 2006, 07:51 PM
I never studied or understood prestressed concrete, but my uncle was building apartment houses in the early 60's, and it was new technology then.

chickenfried
October 18, 2006, 08:17 PM
Would you care to go into your reasons? Also I used the wrong terminology. It's actually a garage. Ground floor of a two story house. But we've always called it a basement :o (nutty Californians) . Entire bottom floor is concrete, so I guess it's a slab home?

I would consider bolting into the studs in the wall behind and or beside (if in a corner) the safe rather than into the floor for a number of reasons.

Erebus
October 18, 2006, 08:19 PM
Rent or borrow a hammer drill. If you are drilling into concrete definately use a hammer drill or it will take forever. Use a bolt that is removable. Tap-Cons might be tempting as they are easy but when it comes time to remove that safe they won't cooperate.

CB900F
October 18, 2006, 08:23 PM
Chickenfried;

Some advice, well meant. Measure three times. Drill exactly in the spot you've very carefully measured. Make sure you drill perpendicular to the concrete. Failure to follow these steps may cause the children to learn new words.

900F

wacki
October 18, 2006, 08:24 PM
+1 on the mask. Although risk is very low for amateur concrete work, it's simply not worth adding the extra risk of Silicosis.

EddieCoyle
October 18, 2006, 08:30 PM
Rent or borrow a hammer drill. If you are drilling into concrete definately use a hammer drill or it will take forever. Use a bolt that is removable. Tap-Cons might be tempting as they are easy but when it comes time to remove that safe they won't cooperate.

This is good advice. Rent the biggest Hilti hammer drill you can get, try to rent the bit too. It'll make short work of the drilling. Don't try it with a standard (non-hammer) drill. You'd be better off with a star bit and hammer.

real_name
October 18, 2006, 08:32 PM
You can get a good hammer drill from Lowes or Home Depot's rental section. They will have a Bosch more than likely. They will also rent you the bits necessary.
Probably cost $40 tops for half a day.
If you are only using 2" or 3" expanding bolts (Simpsons or similar) you don't need to worry about perforating through the floor pad. But if you use a 6" bolt you might find you are in a shallow spot when they poured the concrete, it does happen, and by going all the way through to the soil below you are now allowing moisture to come up. You'll find out in a heavy rain. Like I say though, 2" or 3" bolts will be fine.
Attach it to the wall also, it pays to have multiple points of contact.
If you have no intention of ever removing it then feel free to go crazy with the Liquid Nails too. Might help, might not, but it can't hurt any if you are permanantly installing the safe.
As with any drilling (walls, floors - concrete or drywall) be aware of any outlets and/or pipes that are in the area, and that includes the back of any wall you are drilling. If there is an outlet directly above or below the point you are drilling then expect to hit the cable, move your drilling point accordingly.
If in sufficient doubt get a second opinion.

spooney
October 18, 2006, 08:44 PM
Another tip would be to be sure and use hearing protection, I sure wish I would have had some around back in my rotary hammering days.

Jeff F
October 18, 2006, 10:08 PM
I'd use the Hilti drop ins or their Quik bolts. They are the best anchors bar none.

CNYCacher
October 18, 2006, 10:46 PM
Although I am now a computer geek as well, I worked in construction and as a general fabricator and cabinet builder in a shop. I've drilled concrete more than a few times to anchor things to floors. Here's my advice.

You have exactly ONE chance to make those holes in exactly the right place. If you miss one of them, you will not be able to use a bolt in that location, and will have to move the safe at LEAST 6 inches and try again.

If I was in your position, I would place my safe where I wanted it, and then drill into the concrete through the holes in the safe. Might make for a dusty safe interior, but a helper with a shop vac hose held next to the bit will do wonders to eliminate most of the dust. I would also place the first bolt before drilling the second hole: With that hammer drill pounding away, you might get the safe walking across the floor.

Good luck

Disclaimer: I never bolted a safe to a floor.

langenc
October 18, 2006, 11:10 PM
You mentioned the safe ws to be
..."in a corner". Have you checked for adequate clearance for the door to swing open -all the way?? Maybe not an issue depending on door swing direction.

joneb
October 18, 2006, 11:15 PM
If the bottom of the safe is predrilled then position and plumb safe in it's resting place, then drill from inside the safe , at least to mark the holes. Anching to the wall is a bonus, but you may have a offset from the stem wall to the framing or sheet rock this will need to be fird out before anchoring, and you will most likly need to drill the back and or side of the safe to hit framing :eek: I would use construction grade hold down lags, much better than your average lag. good luck :eek:

Oh did I mention :eek:

joneb
October 19, 2006, 12:14 AM
A word of warning, if your garage slab was done correctly the slab will not be level, it will have upto a 1/4" per foot slope. This maybe more in the corners, and may slope in a x and y axis from a inside corner. :eek:

roscoe
October 19, 2006, 01:04 AM
You can partially fill the hole with two-part concrete epoxy before you put the expansion bolt in. Then, it will really never, ever go anywhere. If you use the style of expansion bolt with the threaded stud poking out, you just pound them into the hole, and crank the nut down after the safe is in place. Yes, rent a roto-hammer, not a hammer-drill. They are different. Ask for a Bosh roto-hammer and it should come in a big steel box and weigh about 20 pounds, with grease leaking out the business end.
http://www.seismicsafety.com/images/Bolt3.gif

You can drill pilot holes from the inside of the safe (make sure the pilot holes are centered), then drill the full holes once the safe is out of the way. Be sure to blow the dust out of the holes (with a straw/tube, using glasses and mask). Fill the hole 1/2 way with concrete epoxy, pound in the expansion bolts, put the safe on the nuts, and crank down.

When you want to move the safe, you can undo the nuts from the inside. The studs would then have to be ground off with a grinder.

tegemu
October 19, 2006, 08:55 AM
I solved all these problems by hiring a professional locksmith to anchor my safe. He had the expertise to resolve all the problems and issues mentioned here including jostling the safe to it's ideal position.. Had all the tools and hardware and was done, cleaned up and gone in 1 hour. Price - $82.00.

a1abdj
October 19, 2006, 11:14 AM
I bolt down gun safes on a pretty regular basis. Some of the above advice is good, and some is a little overkill.

First thing I do is set the safe onto something that keeps it off the floor. If you're putting a safe on carpet in af inished room, that's probably good enough. On bare concrete, I use either 3/4" plywood or rubber stall mat (found at farm stores). This prevents moisture from building up beneath the safe.

After I have the safe sitting where I want it, I shim it to level. Once the safe is level, I check the door swing to make sure it's not hitting anything.

Now it's ready for bolting. I get inside the safe with my trusty Dewalt hammer drill. It's not a big hammer drill, but it's plenty to run 3/8" or 1/2" holes for gun safes. I predrill the wood or rubber with a regular bit in drill mode, then go for the concrete in hammer mode. I can drill a 4" deep 3/8" hole in around 10 seconds with this little drill.

Once the holes are in place, I drive down the sleeve anchors (someone posted a photo of one above), and snug up the bolts. The 3/8" anchors I use have over 1,000 pounds of pull force rating. Four of these bolts in a gun safe give you over 2 tons of pry resistance.

Safe is now installed. I double check how the door is swinging (it shouldn't swing open or closed on its own if level). If it's not, I adjust tension on the bolts to bring it back to level.

Guy B. Meredith
October 19, 2006, 03:59 PM
Just putting in my vote for the hammer drill. After hours of EXTREME frustration trying to drill anchor holes for a patio fence I learned I could rent a hammer drill for $20/day. What a God send!! Took all of 15 minutes for 16 holes.

TX1911fan
October 19, 2006, 05:34 PM
Someone in another post recommended putting the safe on a pallet and anchoring the bolts through the pallet to give a few inches of flood clearance. Sounded like a good idea to me.

Kestrel
October 19, 2006, 06:27 PM
a1abdj,

Are those anchors stronger than just lag bolts and lead anchors? How strong are those?

Thanks.

a1abdj
October 19, 2006, 06:49 PM
Someone in another post recommended putting the safe on a pallet and anchoring the bolts through the pallet to give a few inches of flood clearance. Sounded like a good idea to me.

That can be done, and you can get extra long anchors which will allow you to do it easily. The only problem, is that you now have room to get underneath the safe to lift it or pry on it. It will still slow somebody down, but not as much as it being flat on the floor.

If you're going to put your safe up on a platform, make sure it's closed on all sides to make it harder to get under. I think CB900F mentioned in a thread that he uses 2" steel tube risers. That's a good way to go about it.

Are those anchors stronger than just lag bolts and lead anchors? How strong are those?

I don't know if they are stronger, but I do know that they are a lot easier to use. The lead anchors are usually too big to fit through the holes in the bottom of the safe. This means you have to place the safe, mark the holes, move the safe, drill, then move the safe back. The sleeve anchors go in without moving the safe.

The anchors I use have the specs on the box. I'm sure this is true with any type of anchors. The 3/8" sleeve anchors show 1,025 pounds of lift force, and 800 pounds of sheer force per bolt. The 1/2" sleeve anchors show 1,700 pounds of lift force, and 1,500 pounds of sheer force.

45crittergitter
October 19, 2006, 08:56 PM
If you're using the non-removeable anchors like the pic, I would drill well below the working depth. Then, after you set the bolt there will be plenty of empty hole under it. That way when you decide to move the safe, the bolt can be hammered down into the hole and the hole patched, rather than sticking up to be ground off. Should make it a heckuva lot easier to get a heavy safe off the bolts too.

I always use stainless bolts for this.

If you're close to me (central MS) you can borrow my hammer drill.

Question: If it's on carpet, how do you drill through without snagging the bit in the carpet and making a big dang mess?

CNYCacher
October 20, 2006, 12:01 AM
Question: If it's on carpet, how do you drill through without snagging the bit in the carpet and making a big dang mess?

Couple different ways. Easiest is to mark the carpet with a felt tip marker sticking down the bolt hole. Then move the safe and cut a 1"x1" square hole out of the carpet with your utility knife around each mark.

I watched a guy drill through a cabinet base to mount it to a carpeted floor. All of a sudden a run apears in the carpet at the edge of the cabinet and shoots across the floor. I start yelling but by the time he got the drill stopped, the run was about 10 feet long. He pulls his drill out and about 20 feet of carpet yarn was wrapped around the bit :D This wouldn't have been such a tragedy except this was inside a $500,000 semi trailer that we were doing up as a rolling product showcase for a big company. The carpet needed to be replaced and a bunch of stuff had to be pulled out of the trailer first.

CB900F
October 20, 2006, 08:47 AM
Fella's;

Another easy way to prevent the above mentioned carpet snag is to use a set of gasket hole punches. A set isn't vastly expensive & sure is handy for this type of thing. I bought my set many years ago & don't have a good feel for what one would cost now.

The set consists of a striker, about 4 to 6 inches long. There is a ball retainer on one end & you hit the other end with a hammer. Variously sized hole punches fit on the retainer end. All they are is a circle with a sharp edge. Put one on, one size bigger than your bolt, place it on the carpet & smack it smartly with the hammer. Voily-Oily, like they say in that-there frog-talkin' country, you have a clean hole.

900F

Rovi
October 20, 2006, 10:22 AM
Voily-Oily, like they say in that-there frog-talkin' country, you have a clean hole.Must... stay... on... High... Road.



Must... stay... on... High... Road.



<sounds of excess pressure being generated>



KABOOM!
<head explodes>

:D

45crittergitter
October 25, 2006, 09:15 PM
Thanks, Cacher and CB900. Moving the safe just isn't the way for me to go, for several reasons. Also, I have a piece of plywood between the safe and the carpet, so I couldn't mark the carpet anyway. I will have to drill through the wood, then deal with the carpet. Great idea on the punches, though - I'll probably do that. Thanks again.

eastwood44mag
October 25, 2006, 09:21 PM
Diamond tipped masonry bit + hammer drill + stream of cool water.

Press very little on the drill, keep water flowing. Your bit will do the cutting, just take your time and let it work.

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