What type of Rotary Hammer Drill is best for drilling into a poured foundation?

Question

I need to drill a series of holes in a poured concrete foundation to allow for a 6" vent to be installed. I would like to drill a series of holes in a circle, then multiple holes in the middle to make it easier to chissel out. Any recommendations on types / models of rotary hammer drills?

Answer 1

Can't agree with the air hammer for a vent hole. That's what I'd use if I wasn't concerned with a neat opening and wanted a rough hole fast. The core drill does give the neatest hole, but cost more to rent, and is too expensive to buy for a one time job. It is fast though, and would be my first choice.

The "best" rotary hammer drill depends on how much you want to spend. All the standard manufacturers (DeWalt, Porter/Cable, Milwaukee, Ryobi, etc.) make very good quality RHD's. Pick one based on you're own familiarity with the makers. I tend to use Porter/Cable products. Hilti probably is best, but too pricey for me.

For concrete foundation walls you're looking for the larger size RHD, with a 1/2 inch chuck. You need to be able to hold this thing with two hands and it WILL take some strength AND patience. Don't try to do it all at once, have more than one bit of each size, and you will likely hit at least one piece of re-bar (stop, go around, cut later after chipping out). The older the concrete is, the harder the job will be.

Note: A small bit size will cut faster (marginally) but you'll need more of them. I generally use a 3/8 bit for the perimeter holes, 1/2 inch for the interior holes. Try to mark and "punch" the perimeter holes about 1 inch apart first to get a fairly neat opening.

Good Luck!

Answer 2

Best Rotary Hammer Drill

Answer 3

I first bought the Makita 1 1/8 inch SDS-Plus Rotary Hammer. There were a couple problems with it. The side grip was really hard to position because there are these notches. So the the whole grip had to be removed and then re-positioned again and push down back into place. I used it once. Then when I tried using it again a couple months later, it wouldn't work. So I returned it and bought this one.

First off, their is no comparison between the Bosch and the Makita. I used it to drill a bunch of 5/8 inch holes and it drilled through concrete like butter. The Side grip is very easy to adjust and the depth guide works great. Oh the Makita, you had to tightened the handle as tight as possible to hold the guide, and still it would slide up when drilling.

This drill has an SDS-Plus chuck. I don't think it mentioned that in the description. Overall I'm very happy with this, and highly recommend it.

http://www.amazon.com/gp/product/B003DQO7ES/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B003DQO7ES&linkCode=as2&tag=pereztom-20&linkId=D7NJLVKUUXHCQ6PW

Answer 4

The better way to make a 6 inch hole in a concrete wall is to use an air hammer driven by an air compressor. Not a series of holes as you will hit large pieces of crushed rock which are very very hard and you will eventually give up on that idea.

You can rent an air hammer at Home Depot for about $20 a day an maybe borrow an air compressor or You can buy a hand held air hammer and start chipping away and in due time that hole will get in there.

Answer 5

Best way to do this is to rent a concrete coring machine. This will ensure a perfect circle. Otherwise your circle will be uneven and you risk starting cracks in the slab that will be a problem down the road. (assuming the concrete is at least 4" thick)

Anyway, any hammer drill would work for drilling holes in concrete.

Good luck

Answer 6

Hilti are probably the best, but there are plenty of others.
Hitachi, Makita, Ramset, Dyna.etc
If hireing, the Hire company will have quality equipment.

If you are going to buy get a quility brand that can be used as both a rotary drill, or as an impact drill.

Just watch out for re-bar

Answer 7

Best way Is to core Drill You can Rent it with A Bit Big Enough for 6" Pipe.

Answer 8

Hilti is one of the leaders in hammer drills and you will pay a pretty price for one. They can be rented

Answer 9

hilty is the way to go. if it were me i'd see about renting a diamond core drill, much neater hole...