• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

The J-L Bolt Debate

Interesting. I most often see nutted bolts with welded nuts and washers, though the video didn't mention them. Surprised the expansion anchor has such a high capacity. Also been advised the expansion anchors get sketchy on permitter bolting due to overtightening and break out.

All are subject to competent install. Theoretically, every cast anchor is easily verifiable prior to pour though the IBC only requires periodic inspection. Most post installed mechanical anchors are usually only inspected periodically as required by the IBC. I have seen enough poorly installed post installed anchors that they make me nervous. I have also found smaller anchor bolts and empty boxes on jobs laying near the installed anchors than what is specified on the plans, which also makes me a little skeptical. Adhesive anchors are supposed to be continuously inspected. I have always wondered if that actually happens.

I wish bolts were marked with more information for my own edification, but I assume the engineers and special inspectors know a lot more than I do. I have wonder if engineers build enough overkill into anchorage to account for the fact that some just won't be as effective.

Working on a plan right now. They specify headed bolts, with periodic inspections. It is up to the installers to follow the plans and get it right.
1761140396247.png

I built a shop a few years ago. Monolithic, with J-bolts. I did not wet set them, I used a plastic placement device attached to the forms. Concrete still pushed them around and I had to manipulate some to get them back to plumb and depth, which I think kind of defeated the anti-wet set idea. I suspect most j bolts are wet set, which makes it worse IMO.
 
The main difference between J-type and L-type anchor bolts is their shape and load-bearing capacity. J-type anchor bolts have a larger load capacity and are typically used in heavy-duty applications such as securing concrete foundations in high-rise buildings and bridges. In contrast, L-type anchor bolts are suited for lighter projects, such as securing lightweight post bases and connecting sill plates to concrete.

hrfastener.com

What is the Difference Between J-Type and L-Type Anchor Bolts? - Premium Fasteners & Machining Parts Manufacturer | Hengrui

Choosing the right anchor bolt is crucial for construction stability. J-type and L-type anchor bolts are both popular choices, but they serve different purposes. J-type bolts are for heavy-duty projects, while L-type bolts work best for lighter applications. Let’s dive into the key differences...
hrfastener.com
 
I live in SDC E, every job I've ever seen has hold downs all over the place. Yeah, there are anchor bolts too, usually 4-foot on center, but they're not going to be the critical element in a major event.
 
Sifu said:
Surprised the expansion anchor has such a high capacity. Also been advised the expansion anchors get sketchy on permitter bolting due to overtightening and break out.
Click to expand...
Expansion anchors require specific torque value that will cause the lumber to break apart. If the 3"x3" plate washer is driven flush, you know that the Redhead anchor was installed correctly. With Hilti the washer is only half buried.

What do you see that is wrong in this picture?

1761150017156.jpeg
 
ICE said:
Expansion anchors require specific torque value that will cause the lumber to break apart. If the 3"x3" plate washer is driven flush, you know that the Redhead anchor was installed correctly. With Hilti the washer is only half buried.

What do you see that is wrong in this picture?

View attachment 16872
Click to expand...

I think I know what you think is wrong, but is not actually wrong, but I'll play along.

What do you think is wrong based on 3 pictures, taken over 5 years ago, from over 1000 miles away, and without seeing the approved, engineered plans?
 
Sorry, 700 miles. But still. Come one man, for real? I was just showing off the anchor bolts compared to the hold downs in relation to the conversation. I'm not looking for a peanut gallery comment on "what's wrong" here...

But yeah, now I'm genuinely curious, what do you think is wrong?
 
So the real question is how the CMU is grouted when the J or L bolts are installed. I've seen them just fill the cell below with pieces of the empty lime bags and then set the anchor in mortar. Like that is going to do anything.
 
e hilton said:
No perimeter anchors.
Click to expand...
Perimeter anchors are of the type I show above, and on the approved, engineered plans.
e hilton said:
Interior layout lines were snapped wrong, the bolts are not in the center of the wall.
Click to expand...
More like the bolts were not placed exactly correct, the snapped lines are where the walls need to be. And what code section would we cite? I did actually talk to the engineer about this issue on a couple of walls. He said it was "within acceptable tolerances" and provided the necessary documentation to the satisfaction of the building official at the time.
 
Joe.B said:
Sorry, 700 miles. But still. Come one man, for real? I was just showing off the anchor bolts compared to the hold downs in relation to the conversation. I'm not looking for a peanut gallery comment on "what's wrong" here...

But yeah, now I'm genuinely curious, what do you think is wrong?
Click to expand...
Oh, no thanks. I should know better, but I'm learning.
 
steveray said:
Weve had some issues with those on foundation replacements....
Click to expand...
What kind of issues? Issues with installation or design? Or real-world failures?

I've only ever seen them on a few jobs, always new construction and part of an engineered design. They look like they make construction easier and listing wise they're supposed to be stronger than basic anchor bolts.

Typically, we see the basic anchor bolts and SSTB's with HDU's.
 
Joe.B said:
Perimeter anchors are of the type I show above, and on the approved, engineered plans.

More like the bolts were not placed exactly correct, the snapped lines are where the walls need to be. And what code section would we cite? I did actually talk to the engineer about this issue on a couple of walls. He said it was "within acceptable tolerances" and provided the necessary documentation to the satisfaction of the building official at the time.
Click to expand...

R403.1.6 Foundation anchorage. Wood sill plates and wood walls supported directly on continuous foundations shall be anchored to the foundation in accordance with this section.....

......The bolts shall be located in the middle third of the width of the plate. A nut and washer shall be tightened on each anchor bolt. There shall be not fewer than two bolts per plate section with one bolt located not more than 12 inches or less than seven bolt diameters from each end of the plate section.....

As to an engineer approving the anchor bolts. Engineers do not approve anything and "within accepted tolerances" is engineer speak for Blah, Blah, Blah. The middle third is a tolerance. The plate washers will be sticking out of the wall.

I did ask what do you see wrong. Since one can't see a missing anchor bolt I suppose that doesn't count.

What is not clear in the picture is the amount of the anchor bolt above the concrete that is not threaded. If I am seeing what I think that I'm seeing is correct, those are really long bolts and the plate will be stacked with washers.
 
Last edited:
You must log in or register to reply here.
Back
Top