Drilling concrete for Seismic retrofit tips tricks please.

[EddieWalker]

For what you are doing, I would be careful about buying something too big and heavy. SDS Max is a lot more weight. For small holes, you really do not need all that extra power. There is a reason I have both a SDS and a SDS Max. One I use all the time, the other I only use when I absolutely have to.

 

[PILOON]

For sure a SDS max is the way to go.
We built a 60' X 200' barn for a client and engineers wanted structure "bolted down".
Two guys installed 200+ 6" x 1/2" expansion bolts in one day!
One worker would drill the hole followed by a second that installed them with an electric hammer drill and 1/2" body washers.
That hammer drill (a Hilti) never knew the difference between wood or concrete.

And, LOL, the Hilti was a $100. pawn shop purchase that included about 12 bits.
I still have it after some 15 years of tough usage.
I also obtained a 2 1/2" core bit for it that became very useful for sump exit hoses and occasional hydro installations.
B4 I used to rent Kango's but they always seemed to break down on the job. (might be due to rental lack of maintenance)

 

[NorEaster]

For prepping stem walls for sills we use a HR3210 from Makita, probably bigger than you need.

Expansion bolts are archaic compared to the Titan HD concrete screws made by Simpson. We don't even use J bolts anymore, it's easier to set the entire sill, tack in place with a ramset, and then drill and screw.

 

[dstig1]

My take is very similar to Eddies. An SDS is great for most uses (I think everything is labeled SDS-plus nowadays - that is what most people mean when they say SDS). The bits are easy to find at all decent hardware and home centers (Lowes/Menards/HD/etc), so that is a big plus. Bits aren't too expensive either, until you get into bigger sizes. You can also do things like getting a wide chisel and use it to pop loose tiles and mastic and stuff like that in hammer only mode (these typically have 3 modes - drill only, hammer and drill, and hammer only). When you need big power or, my favortie, driving ground rods, I just rent an SDS-Max for the day. They are pricey, and so are bits. SDS drills can be under $100 to 300, but the Max drills are $4-900, sometimes more. I bought a ground rod driver bit years ago (hard to find) and that is worth it's weight in gold, but it is an SDS-max only bit. Most holes you need will be in the sweet spot for the regular SDS drill. 1/2" in concrete is a perfect example for that. If you ever drill for Tapcons, you will be surprised how fast those tiny holes go in. ZIP!

 

[Tompet]

My take is very similar to Eddies. An SDS is great for most uses (I think everything is labeled SDS-plus nowadays - that is what most people mean when they say SDS). The bits are easy to find at all decent hardware and home centers (Lowes/Menards/HD/etc), so that is a big plus. Bits aren't too expensive either, until you get into bigger sizes. You can also do things like getting a wide chisel and use it to pop loose tiles and mastic and stuff like that in hammer only mode (these typically have 3 modes - drill only, hammer and drill, and hammer only). When you need big power or, my favortie, driving ground rods, I just rent an SDS-Max for the day. They are pricey, and so are bits. SDS drills can be under $100 to 300, but the Max drills are $4-900, sometimes more. I bought a ground rod driver bit years ago (hard to find) and that is worth it's weight in gold, but it is an SDS-max only bit. Most holes you need will be in the sweet spot for the regular SDS drill. 1/2" in concrete is a perfect example for that. If you ever drill for Tapcons, you will be surprised how fast those tiny holes go in. ZIP!

Good description. I bought this Makita in 2010 and it is very solid. This is a pretty good price on the same one with the included grinder. You can find it for a less online w/o grinder. The short overall length of this style vs straight d handle style works well in tight positions and it is pretty light. As stated above make sure it has all three modes including hammer only.

Makita 1-1/8 in. SDS-Plus Rotary Hammer with 7.5-Amp 4-1/2 in. Angle Grinder-HR2811FX - The Home Depot

 

[ultrarunner]

Did exactly what you are doing about 15 years ago and bought a Bosch Bulldog SDS hammer drill... it was like butter drilling.

Also bought the right angle attachment because some places had almost no clearance.... not quite as effective in that it was slower.

Drilled thousands of holes with that little SDS and still going strong... 1/2 is right in the middle of capacity or 7/8 listed

Here is a similar model rated at 1"

11255VSR 1" SDS-plusｮ BULLDOG Xtreme Rotary Hammer | Bosch Power Tools

I also have larger Hammer Drills... but for retrofit... the small SDS can't be beat.

 

[skylarkguy]

Thanks for the suggestions.

To button this up i found a used milwaukee model 5303-2 11/8 rotary hammer.

I installed 20 brackets in half the time it took to put in 8 with the hammer drill. The holes were not only faster but straighter and cleaner. Probably the best $50 i ever spent.

I still have 5 more to install but first have to figure out how to squeeze myself through a small passage.