Shoring existing face bricks for (3) course brick removal 1

[Azmarya]

I'm working on a job where they will be removing the lower three courses of brick in order to do concrete spall repair work. We need to shore the existing bricks above. Normally, we would recommend a temporary relieving angle anchored into the backup masonry. However, the wall is made up of (1) wythe face brick and the backup is CMU. Anyone have recommendations on how to go about shoring this? Attached are section and elevation view of removal work.

Thanks!

 

[Azmarya]

Attached is the elevation.

 

[Azmarya]

I forgot to mention, we did recommend to install a c-channel above the removal work, but the contractor is asking for other options...

 

[mfrad]

Asma_F
We have used 2 x 4 wood studs as shores spaced at 24 inch to 42 inch on centers to remove up to six courses of brick masonry. (We have also used steel pins epoxied into the backup wall to the outer wythe.) Your wall detail shows solid wall construction which most likely has a 3/8 inch collar joint; so no need to cut the brick to install flashing. I would not use Jahn's mortar since it is not an appropriate structural repair to support masonry. See Cathedral Stone web article.

https://www.masonrymagazine.com/blog/2012/10/25/stone-patching-extending-the-life-of-masonry/

 

[DM2222]

6. THE STRUCTURE IS DESIGNED TO BE STABLE IN IT'S FINAL FORM. THE DESIGN AND SAFETY OF ALL TEMPORARY BRACING, SUPPORTS SHORING ETC. NECESSARY FOR CONSTRUCTION SHALL BE THE SOLE RESPONSIBILITY OF THE CONTRACTOR.


This is how I would do it. lol, Are you required to direct the shoring work? I would not be all that comfortable with that without being onsite for most of the work- potentially too many circumstances/unknowns/conditions that might require some deviation/common sense. I have been surprised a couple times by how it was done. I've seen it down a few ways: (without engineer's direction) - Cut 2x4 cripples in every so often to support. I've seen them just leave a brick "column" every so often. (and by "every so often" I mean about 3x as far apart as I would have been comfortable) Like I said - I've been amazed before. Mostly arching action that allows it, but of course that may not help in every situation. A good, experienced mason would be invaluable on this project.

 

[XR250]

Agree with DM2222 - Let the contractor figure it out.
I have agreed to do one shoring plan in recent memory.
It was ignored as it was too complex.

 

[Azmarya]

Thanks for the responses!

These details are from contract drawings that were already prepared/approved. We are responsible only for the design of shoring of structures during the work; not required to direct it.

For timber shoring, we usually recommend wood frames constructed of 2x4 members - one at the top and one at the bottom in header position laid flat and then 2x4's in between at 24". The area of work is too small for this type of frame though. @mfrad your suggestion of 2x4 vertical studs would give enough room for the work to be done. You've used 2x4 wood studs by themselves? I'm thinking suggesting reinforcing the two courses of brick above removal area with helical ties and then using 2x4 wood studs @ 24"

 

[r13]

Use segment horizontal 2x4 and vertical 2x4 studs. Depends on the pace of the repair, they can freely remove and reshore the unfinished area in a segment.

 

[mfrad]

Asma_F,
don't use spiral helical ties, use hilti, or equal, minimum 3/8 inch diameter epoxy set anchors set at a slight vertical angle to carry brick veneer gravity load and any horizontal load if masonry has outward bulges. Do anchor proof test etc. Helical spiral anchors are flat steel elements and have no bending capacity only tension.

 

[DM2222]

I agree with retired13 on the pace if possible. My dad would say "do this the same way you would eat an elephant - one bite at a time"