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Discussion Starter #1
I'm having a hard time drilling small pilot holes to attach capping for a small section of foundation wrap I installed. I'm using a 1/2" Dewalt corded hammer drill with a Ryobi 1/8 masonry bit and also a Tapcon 5/32 bit. I can only get about an inch in and it won't go any further. It seems like I'm hitting some hard aggregate. Don't think it's rebar but I could be wrong. Could rebar be that shallow in the foundation? I managed to drill 10 holes already to attach the membrane but had trouble doing them. I ended up going through 3 bits so far. I could only drill an 1" 1/4 in one hole and had to cut the Tapcon screw 1/4" to attach the plug to the membrane and foundation. I'm also using zinc coated #8 diameter 1"1/2 green screws which I don't think they're meant for concrete but they work and the website for the membrane states that plated or galvanized screws can be used. I drilled 3 holes from the bottom of the foundation to the top but I only managed to drill to the correct depth of 1"1/2 at the bottom hole. I can only drill about an inch in the other 2 holes and then I get stuck. The holes won't go any deeper. I damaged a few bits already trying. Should I use a rotary hammer drill with an SDS bit as I've read other forums saying it would be much easier and more hammering power with a rotary hammer drill. Can I just use a better drill bit to accomplish this task b/c the holes I need to drill aren't deep and big. Or can I just use 1" plated screws b/c it worked when I tried using 1" brass plated wood screws. I know it's not the right way but I'm only attaching the plastic cappings. Any help would be greatly appreciated
 

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I'd try a better set of bits. I use the Bosch bits.
Ron
 
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What he said, make sure bits are rated for percussion drills. Yes rotary hammer is better, but also more expensive. What you are hitting is aggregate stone in the concrete. You can drill threw it but that stuff can be really hard. Add a little water in the hole to cool the bit.
 

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Discussion Starter #4
I got a 5/32 Bosch Blue Granite hammerdrill bit from Home depot today and it got chewed up faster than the Ryobi and Tapcon bit. Maybe I was pressing too hard. I managed to only finish one of the holes I started. Frustrated, I went back to HD and rented a Bosch rotary hammerdrill which came with a 5/32 sds carbide tip drill bit. The rotary did the trick. Drilled the holes like a hot knife through butter. What a difference of power compared to a regular hammerdrill. I drilled all the holes except 1 hole that was really stubborn. I managed to get it done but I chewed up the SDS bit. Luckily it was the last hole I had to drill. When I went back to return the drill the guy at the HD rental center asked if I needed another bit so I would've managed anyhow. Anyways, thanks for the advice from you guys, unfortunately it didn't really help but good to know anyhow.
 

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I think I saw somewhere that rotating out your bits and allowing them to cool between holes improves their lifespan.
 

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none of our hammer drills are fitted w/jacobs chucks - ONLY sds, spline, or sds max,,, we don't notice too much difference in the quality of bits to fit those chucks BUT jacobs won't 'hold' the bit while the hammering happens,,, the avg h/o hammer drill is a pita - rent a decent 1 if you have no permanent need for it,,, normally a h/o can have a variable speed 1/2" drill & be happy all his life - owning a true 1/2" drill is not a need for a h/o
 
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