Drilling holes in concrete for wedge anchors?

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Can anyone tell me how you do this? I have some stalls in the barn coming loose and need to reanchor them, but can't get through the concrete with my masonry drill bit. The concrete is 20 years old and was made with mixed kinds of rock; granite, limestone, etc. Service people here to do other work have reanchored the stalls before managing to get through the stuff (they have commented it's very hard concrete), so what is it I'm doing wrong? Is there a trick to the drilling or am I just going to have to find a different solution? I'm trying to do this myself this time to save a few bucks, but the frustration level is rising . . . Thanks.

-- Jennifer L. (Northern NYS) (jlance@nospammail.com), February 15, 2002

Answers

Drill a pilot hole first with a smaller bit. This isn't as precise in concrete as stell or wood the bigger bit might wander a bit following the pilot hole but it shouldn't make a huge difference for anchoring stalls.

-- Ross (amulet@istar.ca), February 15, 2002.

Some time with OLD HARD concrete it will be nessary to use a roto hamer drill...Hilti makes one as well as other brands. this is a concrete drill with a internal hammer device that makes drilling concrete a breeze in most cases. These can be rented at most tool rental places but it may be cheaper to have one of your local contractors just drill a few holes. Our local tool rental (Houston Tx area)get 50$ for a 4 hour rental,thats to high for 20 minuits work!! Good luck in Your project.

God Bless and have a great weekend.

-- Charles Steen (xbeeman412@aol.com), February 15, 2002.


A hammer drill is the way to go.Maybe borrow one or rent one but it sure will be faster and alot less work.I use a product called Tap- Con,for anchoring stuff to stone,concrete,&brick. they look like screws and don't need a large hole like other type fasteners.They come in all kinds of sizes,and are removeable.

-- Steve in Ohio (stevenb@ohiohills.com), February 15, 2002.

A hammer drill is absolutely the way to go. I bought one (~$130 Dewalt) last summer to use while building our home. I can't believe the difference between drilling in concrete using a hammer drill and hammer drill bit versus using a standard rotary drill with a standard masonry bit. Some drills are both hammer drill and standard rotary. That's what I bought, but don't forget to switch the hammer feature to ON when drilling concrete.

-- Steve in So. WI (alpine1@tds.net), February 15, 2002.

Go to the hardware store get a star chisel (that is what I call them) of the right diameter. It looks like a hex bar with a tip that has a cross or several crosses. Now take your 4 pound engineers hammer...or short handled sledge and whack the chisel, turn it slightly, whack it again, etc. If you get in the groove with this, you can drill a hole fairly quickly, you don't need power, you will learn an old way, and if you want to drill in granite later, you can do that too. This is basically the hand version of the hammer drill. Oh and wear safety glasses no matter which way you do it.

Have fun.

Oscar

-- Oscar H. Will III (owill@mail.whittier.edu), February 15, 2002.



Go rent you a Ram-set Gun and shoot the anchor's through the stills into the concrete...

-- Warren-NC (w.baucom@worldnet.att.net), February 15, 2002.

Thanks, you guys. :) I knew someone here would have some answers for me. I'll check out what you've said and see if I can't makes some holes, afterall. What a great bunch everyone here is!!

-- Jennifer L. (Northern NYS) (jlance@nospammail.com), February 15, 2002.

I use a new bit when drilling old concrete. I have only used my normal drill. When the bit encounters a rock head on, it will not go through. I have found that I can fracture the rock in the bottom of the hole with a punch and sledge hammer. Once cracked, the bit can get a bite and continue down. It tends to ruin punches, but can be cheaper than renting or buying a roto hammer every time you need to drill for an anchor bolt somewhere.

-- Skip in WA (sundaycreek@gnrac.net), February 15, 2002.

I agree, either buy or rent a hammer drill if you have electricity close by, and use molly bolts. Molly bolts have an expandable sleeve with a bolt inside. Drill the holes to the deminsion of the molly bolts and simply slide a molly bolt down inside and tighten the nut on top. If done correctly this will hold down just about anything.

-- r.h. in okla. (rhays@sstelco.com), February 16, 2002.

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