Drilling through block foundation

[Mesh]

I've got a Hilti TE-7C which is a nice little rotary hammer that has served me well.

I have a service upgrade to do that I am going to have to come in through the block foundation. Because the layout of the joists and the proximity of the first one to the wall, I won't be able to come in through the rim joist like usual.

I need to drill a clean 2 1/2" hole through the foundation in order to bring the 2" PVC through into the back of the panel. Is there any way to do this with my TE-7C with SDS-Plus chuck? I'd rather not do the "many little holes" method if I could avoid it.

 

[infinity]

What about a thin walled core bit?

http://www.hilti.com/holcom/page/module/product/prca_rangedetail.jsf?lang=de&nodeId=-16489

 

[Mesh]

What about a thin walled core bit?

That looks nice. Do you have any experience with bits like that?

 

[iwire]

They work fine.

But block is easy enough to make a decent hole with a hammer, either way you end up with a gap that needs patching or caulking.

 

[infinity]

That looks nice. Do you have any experience with bits like that?

Yes, they work well in block, but in poured concrete not so well because they're very slow and almost useless if you hit rebar.

 

[Mesh]

I see.

I'm sure I will find a lot of poured foundations or at least block filled with concrete. Maybe it's better than I save this $100 on the bit and put it towards an SDS-Max rotary hammer. I got my eyes on that Hilti TE-70, I could drive ground rods with that!

 

[ActionDave]

When the hole size gets big enough to need a core bit hiring concrete contractor can be a cost effective way to get the job done and save some hassle.

 

[GoldDigger]

They work fine.

But block is easy enough to make a decent hole with a hammer, either way you end up with a gap that needs patching or caulking.

As long as the foundation wall depth is less than twice the depth of the bit, or else you chisel out the core material partway through, it should work.
Having a coring drill with mounting accessories that let it run without you having to keep constant pressure on it is another strong argument for bringing in a contractor to do the job. How much is your time worth in addition to the cost of the bit?

 

[iwire]

We are talking about a 2.5" hole in a block wall. There is no way I would call in anther contractor to do it, I would be done in a few minutes unless it is filled solid and has rebar etc.

 

[ActionDave]

We are talking about a 2.5" hole in a block wall. There is no way I would call in anther contractor to do it, I would be done in a few minutes unless it is filled solid and has rebar etc.

That is because you are as strong as you are good looking.

The OP did use the word foundation. Where I live that equals solid concrete or core filled block every time.

 

[Mesh]

I couldn't imagine brining in a coring contractor to drill a single 2.5" hole in a residential service upgrade.

 

[kwired]

I couldn't imagine brining in a coring contractor to drill a single 2.5" hole in a residential service upgrade.

and do the job at a cutthroat price on top of it all:happyyes:

 

[iwire]

That is because you are as strong as you are good looking.

Well yeah ......

The OP did use the word foundation. Where I live that equals solid concrete or core filled block every time.

I don't run into many filled blocks.

 

[kwired]

I don't run into many filled blocks.

I don't either. They usually only did so every so often and not the entire wall. If doing the entire wall, why not just pour the wall in the first place?

 

[Lectricbota]

I just go to the local rental shop, pick up drill and bit, have it back in 30 minutes (most of the time), give them 35 bucks and be done with it.

 

[GoldDigger]

I don't either. They usually only did so every so often and not the entire wall. If doing the entire wall, why not just pour the wall in the first place?

They don't have to build forms for one thing....

 

[kwired]

I just go to the local rental shop, pick up drill and bit, have it back in 30 minutes (most of the time), give them 35 bucks and be done with it.

If I did that it would take about an hour and a half to pick up the drill, 15-30 minutes to drill the hole, and another hour and a half to return the drill, or I get my drill off the shelf in the shop and use it as needed. :happyyes:

2-1/2 - 3 inch holes are a bit much for SDS drills. If you are going to do that size very often you need a spline shaft type drill at a minimum.

 

[Mesh]

I

2-1/2 - 3 inch holes are a bit much for SDS drills. If you are going to do that size very often you need a spline shaft type drill at a minimum.

You mean SDS-Plus drills, right? SDS-Max drills are on par with spline, AFAIK.

 

[Lectricbota]

If I did that it would take about an hour and a half to pick up the drill, 15-30 minutes to drill the hole, and another hour and a half to return the drill, or I get my drill off the shelf in the shop and use it as needed. :happyyes:

Or that. I just don't need it that often to justify buying it.

 

[kwired]

You mean SDS-Plus drills, right? SDS-Max drills are on par with spline, AFAIK.

Really don't know much about SDS drills, don't have one. Have used a couple different ones over the years that belonged to others. If I need 1/2 inch hole or larger I use my spline drill. If drilling holes for smaller anchors I use standard hammer drill. I suppose if I had to drill a lot of holes the SDS would be worth looking into, but I generally do not run into jobs that require a lot of drilling of smaller holes in concrete.