CMU Wall Mods - Closing off Doorways & Windows

[JoelTXCive]

We are doing some wall modifications to an existing split face CMU building.

There is an existing generator that is being removed from a building. Once it is removed, we need to ‘brick-up’ or fill-in all the existing vent & louver openings in the CMU.

Does anyone have a resource for repair details? I’ve tried googling, but not had much luck.

I’m not sure how I should reinforce or tie the proposed CMU into the existing. The only loads will be a wind load and possible vandal/thief load due to all the electrical equipment in the building.

I’m assuming I have fully grouted cells all around the existing openings that I can dowel into, but I don’t think I want to put dowels upwards into the lintel.

Attached is what I have come up with so far and below is a photo of the building.... Any input would be appreciated.

Thank you!

 

[JoelTXCive]

Ohhh......I (now) realize I have a spelling error in the photo leader ('an' should be 'and').....I'll fix that in the plans.

 

[dik]

Can you still get similar masonry units to match? Did you want to 'tooth' the masonry joints to make it blend in as much as possible. If the cores are grouted, this may be a problem. In past, the trim around many masonry openings was conventional construction. Have you checked? Is appearance an issue?

If conventional masonry design there should be no issue in just replacing the CMUs. Any competent mason should be able to do the work.
No special attachment should be required. Is the foundation designed for the opening, or full masonry. The condition at the roof could be interesting, although the size of the building doesn't seem too large for lateral. Seismic? Care to be taken for flashing at this area and blending it into existing, or replace existing.

Can the opening be replaced with CFS steel stud and veneer? or CFS steel stud and prefinished 'wrinkle tin'. Is it a security issue, or fire issue?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[haynewp]

We’ve done similar details to yours several times. The smaller width opening can likely omit the vertical bars. You will need to trace the load path at the larger opening for out of plane wind. If this is enclosed now, I would also consider moisture tightness required at the new to existing block interface for driven rain.

 

[JoelTXCive]

Thank you Dik & Haynewp.

Those are both good tips.

I'll check with the mechanical & electrical engineers who are driving the ship on this project, but I'm pretty sure they are going to paint the whole interior & exterior of the building after the modifications. Also, the building belongs to the State highway department so they are not too concerned about aesthetics.

 

[Deadblow]

I would suggest grouting all cells of the infill solid. It would add very little cost and would be stronger, more resistant to vandals, and more resistant to moisture intrusion.

EIT

 

[dik]

and added weight?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Aesur]

Why don't you want to dowel into the existing lintel? You are adding a new infill wall below, this will become load bearing, so the lintel will essentially be nothing more than some out of plane transfer mechanism, if even that after infilled wall is installed. I typically specify epoxy dowels around perimeter with masonry infill, horizontal ladders and vertical bars. More than likely they have an existing footing that is the same width across the bottom, if you suspect they don't run a few calcs and you will most likely find a 1' wide footing probably works. Depending on location, seismic mass could be an issue, however it is my opinion that yo would find it to be negligible in a structure this small as the diaphragm can most likely handle it and you are technically making a more solid shear wall on that side. Also being that you are in Texas, I doubt you are a in an even moderate seismic zone. Wind loading to the structure remains unchanged most likely.

 

[SE2607]

I would reinforce with bars and dowels, both vertical and horizontal then use pneumatically placed concrete. It seems difficult (to me) to fit in all that block horizontally and then grout the wall after the CMU: is in place. If aesthetics are an issue, you can use a form liner and colored concrete.

 

[JoelTXCive]

These are all great comments.

The state provided us the original construction plans from 2003. The building is supported by a 12" thick waffle slab that has 3ft deep grade beams. (Probably because of the generator and 5:1 concrete mass guideline)

Aesur - that is a good point, once I fill in the openings, the lintel ceases to be a lintel. No reason why I couldn't dowel into it.

SE2607 - You might be on to something with the shotcrete! I have no experience with it, but TxDOT does have an existing Shotcrete specification for soil nail walls. I might keep my existing CMU details, but add a note that the contractor can submit a shotcrete closure plan at their option for our review and approval. This might be a lot easier. The existing CMU is 12" thick, so we could dowel a single (or even double) mat of rebar around the opening; put up plywood forms inside the building, and then blast it with shotcrete.

This is all good stuff. Thank you everyone.

 

[SE2607]

As an alternative to pneumatically placed concrete, you could form and pump concrete. Again, you could use form liners and colored concrete if aesthetics are important.