Drilling strategy

[bluedog225]

Good evening,

At the strip of exposed concrete between the siding and the barn door, I’ll be drilling holes for titen HD 6” long 5/8” diameter fasteners in the face of this concrete wall to mount a piece of 6”x6” angle iron about 25’ long. Holes about every 3’ (from memory). The walls are 10” thick.

[edit-this is part of the balcony project.]



I wish I’d taken more pics. This is the best I have. I know more steel was added around the man door. And some more 45 degree pieces around the top corners of the doors. The area I’m concerned about is above the large door. I believe the rebar there is accurately reflected In the pic.

Counting the from the tie holes, and looking at the plywood seam, I’m pretty confident the rail for the barn door sits right at the heavy #7 rebar concentration at the header of the large door. Several of the holes in the angle iron I’m going to mount are going to fall into the #3 stirrups above the large door at 4” o.c. The door is 9’ wide.

Simpson requires a drilled hole for titen anchors. Not cored. The best strategy I can think of is to drill holes every 12” in the angle iron to allow for alternative hole placement. Or have a core drill handy and epoxy in 5/8” threaded rod if I hit rebar.

Or is punching through a couple of the 3/8” stirrups ok in the grand scheme things? I’m pretty sure that’s what the crew would do if I weren’t around.

Or I can go back to the engineer for other solutions. But that consult seems better after we give it a shot and if I end up with at least a couple of shallow holes that need an alternative like epoxied threaded rod.

What do you guys think? And thanks.

 

[BombShelter]

I would think a medium-size Bosch Hammer Drill (RH-328VC, or whatever this model is called now)and a Bosch Bulldog X-treme Bit (for concrete with rebar) would work. I hit rebar drilling through sidewalks/driveways once in a while and 85% of the time can power through but it takes 3x longer than a regular hole. Looking at that web I'd probably get at least 2, maybe 3 bits, it's no fun if they break in the field, I just had one snap today but it's very rare. They tend to lose carbide when drilling rebar, so check often if the drill is not moving.

I don't know the rebar layout pattern when I'm drilling, I'm assuming I'm cutting through some of it or I'm extremely lucky.

Interesting project, it's almost zombie-proof. Personally I'd move up north and kill them when they freeze in winter.

 

[dcg9381]

Interesting project, it's almost zombie-proof.

That explains it.


Winchester did it first, but I now know who to PM during the apocalypse...

 

[bluedog225]

Goal

 

[JWILLIE1977]

Seems like the perfect opportunity to hire a firm that specializes in concrete scanning to locate the rebar. 2 hours worth of scanning and layout could save you hours of hammer drilling. Yes, your anchor layout may change but your rebar will remain intact.

Be aware, core drilling isn't the preferred method of installation for epoxy installed anchors. Core drilling leaves a very smooth concrete surface that the epoxy does not like to bond with. While it can be done, it's recommended that the smooth concrete surface be roughened to create friction.

Besides, no one likes coring drilling through #7 bar. . . Or #14 bar for that matter. Been there. Done that.

 

[PopcornSutton]

Looks like you can drill under the #7 horizontal bars, which is the strength of the beam. Drill at 3' centers you'll hit a few bands, but I wouldn't lose any sleep over those. You hit bars, you have to either drill new holes or core drill.

 

[bluedog225]

Agreed, core drilling is a no go for the titens. And may need more prep if I try epoxy.

I’ll ask look around for scanning. But seems unlikely that’s going to be an affordable option for this one install on this little project.

Drilling a hole every 12” in the angle iron is sounding like the best option. I went back and looked at the plans. The engineer wants anchors (shown as 1/2x6 on the plans) every 32” between the beams. I should be able to beat that.

And I’ll need to be careful not to hit the HDU’s. But those are visible from the inside and can be avoided.

 

[PopcornSutton]

I've seen Hilti expansion anchors installed in cored holes many times. Give them a call and ask.

 

[bluedog225]

I've seen Hilti expansion anchors installed in cored holes many times. Give them a call and ask.

Thanks. I think I’m going to drill what we can and see how much rebar we run into. It’s good to know that there are cored solutions available.

 

[CraigStu]

Would there be any way to put posts against the wall matching the posts supporting the outer edge of the balcony. You would still want some bolts to tie it to the wall but they would be much less stressed if they were just keeping it against the wall vs supporting it.

 

[bluedog225]

Would there be any way to put posts against the wall matching the posts supporting the outer edge of the balcony. You would still want some bolts to tie it to the wall but they would be much less stressed if they were just keeping it against the wall vs supporting it.

That would have been easier. But that big barn door prevents a post.

Instead, there will be a 6” piece of angle iron with gussets bolted to the concrete. And the beams for the deck will rest on that.

 

[wssix99]

Call your engineer. If they did those drawings, the consult and question should be free.

This doesn't look right... I have a similar type of build and we poured the wall with the ledger system and bolts already in place to avoid the problem you are facing now. Maybe he thought that you should be able to work through 4" OC stirrups?

I'd also double check that the beam is intended to take the point loads of the deck and wall since there is no mention in the elevation. You might also confirm the rebar in the beam above the door. The elevation seems to imply that the bars should go the full length of the wall but there are some short pieces in the picture.

BTW - Handling water that runs down onto the angle iron will be interesting. I'm not sure how you would flash that detail and keep water from pooling on the angle.