Masonry Repair?

[SteelPE]

I have a building that is currently under construction that is almost complete (80% at this point). The structure is built in accordance with IBC 2015 and is masonry bearing.

In typical architect fashion, they decided to vary the color of the block to create some fancy architectural accents. The project has been a thorn in everyone’s side with a change in exterior skin from insulated metal panel, to tilt up to CMU. Well during the rendering process, the architect made a mistake along one side of the building with the placement of the color band and it was placed at the wrong elevation. This issue is this color band is correct everywhere else and the GC didn’t question why the color band was placed at a different elevation at this one location.

So the architect is looking to fix this error which occurs along 60’ of perimeter wall. They are looking to remove the face shell of the block and replace it with the proper block face shell (an approximate section 16” wide x 60’long). I am a little hesitant to this repair this because we have a bond beam in this area. The wall is heavily reinforced due to a number of openings in the wall (12" CMU with bars at each face).

Are there any drawbacks into what the architect is proposing (thinking development length, bond between the face shell and the grouted cells etc)?

In 20 years we have never even attempted this type of repair.

 

[JoelTXCive]

I'm sure the architect is worried about the change order that he is either going to have to sell to the owner or eat himself.

Is there any room in the middle? This idea sounds like more trouble than its worth, but I'll throw it out there. If the section is 60ft long, then could you remove and replace three 10ft segments; and then do the face repair on three 10ft segments?

 

[phamENG]

KootK - I think what EZBuilding is getting at is that it's rare that a face shell is added after grouting. Usually, the face shell that's removed is either going to be covered by a finish or is in an industrial space where the appearance doesn't matter. So they just put some plywood up against the wall and grout it. The grout fills the space usually occupied by the face shell, so it's all solid.

 

[KootK]

Well, one thing that I would say is definitely not SteelPE's problem is the aesthetic outcome of this repair. If it looks like butt when all is said and done, somebody else gets to own that part.

 

[EZBuilding]

phamENG got where I was going with it. I don't have much faith in the face shell being adequately bonded to the remaining masonry wall to consider it to be contributing to the assembly. Where as the filled in grout at a cavity would.

I don't know how they are going to be able to remove the face shell without wrecking the masonry web. Seems like that will be challenging.

After reviewing the remaining wall assembly for strength and deflections, I think your next worry would be serviceability. It's unlikely the new face shell will be providing much protection from moisture getting behind it. Could that lead to premature corrosion of the reinforcement within the shell?

 

[SteelPE]

Oh, this is still that building... I've seen some of your other posts and I do not envy your position. I hope you are remembered as the great consultant that helped solve problems that were created by others, and not have your name simply attached to a project riddled with issues.

I'll take this as a genuine comment. Yes, it is that building. I have referenced this building quite a few times in these threads over the past 7 months. It's been a thorn in my side for a while, to the point where I wished I had passed on the project when it came up.... and no, I will not be remembered as the great consultant... but rather the consultant that wasn't the team player and just covered everything up.

I suppose when I can get some additional time I will dig into it a little more. The only way I am going to try to justify this is by not relying on the face shell on this bit of masonry. I am going to check the bending capacity at the effected section and then check the demand at the same spot. If I can get it to work I will then need to see where this hits in relation to the lapped splices. If there are any splices behind the repair then I suppose that will be grounds for denying the repair (as splice is dependent upon cover which we are reducing).

I can't stand making an aesthetic repair to an item that is in place. This just screams sacrificing structure to make something look better.

 

[Eric C.]

Is it possible to just stain or dye the block faces to the desired colors?

 

[jittles]

I can't stand making an aesthetic repair to an item that is in place. This just screams sacrificing structure to make something look better.

I understand the feeling! At the end of the day, I remind myself that the structure of a building only exists to support its other functions. And if aesthetics are an important function, then the structure sometimes has to go along for the ride.

My other comment was genuine - first there's the immediate problems at hand, then there's the bigger picture of how it all is perceived by potential future clients.

I've had projects go wrong to no fault of my own, but the game of professional telephone gets back around to me and it has sure sounded like it was all my fault. Unfortunately, there's little you can do when you're not there to defend yourself. If you come up with any slick ideas on that front, post em up!

 

[r13]

Could you "glue" glazed CMU faces to the existing block?

Yes, positively done. Back to home, a hot-humid, salty aired island, all facade are covered with ceramic tiles (not brick tile), with cement mortar, on concrete and brick walls - a low tech high skill work.

 

[masonrygeek]

From a structural standpoint this could probably be done with little impact. The bigger question is the durability of the repair and the ability of the mason to actually remove the existing face shell (not easy in a grouted wall) and put one back in place. The surfaces we are talking about will be uneven at best. Will the repair with the correct color look any better than a wall where the colors don't match. I would suggest doing a test on a small area to see the effects before you remove 43' of masonry and realize it looks like crap.

As for gluing a glazed face shell onto the wall, I'd be leery about that bonding to the wall over the long term. There are masonry stains that can match just about any color (but not texture). Companies like Nawkaw (

https://nawkaw.com/)

and Exact Match (

https://masonrystaining.com/)

can stain the units to match their intended color. A masonry stain is better than paint as it will last longer. Just another possible solution to this problem.

 

[dhengr]

SteelPE:
They could take the wall down to the elevation of the problem courses and rebuild it properly and adequately. That is the starting point for any discussions. You didn’t come up with the crazy aesthetic design or need, and you didn’t do the Arch’s. inspections for him, where he might have caught this problem, nor did you make the construction error which caused the current problem. You are not a structural magician on call to correct or resolve all of their stupidity and lack of attention to detail. You will help them to resolve this problem, as best you can without weakening the structure, but the liability, responsibility and serviceability of any corrections are theirs alone. It’s their fault, it’s their problem, and any fix should not work to the detriment of the structural integrity or serviceability of the building, and you want written contractual paperwork which absolves you of any responsibility for their fix. Ask your insurance company how to handle this. As long as you are already their s.o.b., behind your back, you might just as well be upfront about protecting yourself from responsibility for their errors.

 

[davidy2020]

ywa,right