Drilling into concrete floor

[chickenfried]

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.

 

[Taurus 617 CCW]

Just use a hammer drill and a good concrete bit and you will be just fine. Don't forget your dust mask!

 

[Mannlicher]

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]

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]

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]

Anchor Bolts

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]

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]

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]

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]

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]

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]

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 (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]

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]

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]

+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]

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]

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]

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]

I'd use the Hilti drop ins or their Quik bolts. They are the best anchors bar none.

 

[CNYCacher]

Align the holes

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]

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]

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 I would use construction grade hold down lags, much better than your average lag. good luck

Oh did I mention

 

[joneb]

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.

 

[roscoe]

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.

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]

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.