Sleeve in Historic Masonry

[phamENG]

In all my past historic projects, the mechanical was put up on the roof and/or in a closet. Have one now that has units on the ground outside and they're running lines through the walls.

Historic brick masonry (100+ years old, 2 to 4 wythes thick, solid with no cavity).

Having trouble deciding if I want to have them drill through the wall or remove bricks individually, cut them, and replace them. Then, once the sleeve is in place, to I have them dry-pack it or inject epoxy into it? They can fill the sleeve with a typical penetration sealant, but I can't make up my mind on the sleeve-to-brick interface. Anyone have any ideas/words of wisdom to share?

Thanks.

 

[bones206]

I lean towards coring an oversize hole then drypacking around the sleeve. Seems like the easiest and cleanest way to go about it.

 

[1503-44]

Minimize the damages.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[kipfoot]

coring is a very clean and quick way to do it. I like the idea of epoxy around the sleeve because you can core a smaller hole. With drypack around the sleeve, you'd want the hole bigger by, say, 1/2" all around and that leads to removing more material and using larger equipment.

 

[1503-44]

Pipe engineers generally prefer a flexible material or a sleeve filled with it immediately adjacent to the pipe, so as not to anchor it to the wall or place a bearing load, or any type of other load on the pipe.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[bones206]

My only hesitation with epoxy injection is perhaps it might take a little more skill and experience to do right, whereas any mason should be able to dry pack skillfully.

 

[phamENG]

1503-44, thanks - that's the whole point. We're putting sleeves in the wall so the plumbers, HVAC techs, and electricians have nice places to run their stuff without tying to the wall.

kipfoot - that was my thought as well, but I was also concerned with future changes or rework for the current project. If we grout it in, a laborer can always chip it back out again. Epoxy might be a litter harder to undo.

bones - thanks, that was my original inclination as well.

I'll have to consider a little more. It may be a 'at contractor's option' thing (at least when I trust the contractor.)

Thank you!

 

[EngineeringEric]

Pham, I would recommend not drypacking with just any grout. I do recommend drilling and filling in, but filling in should be a soft mortar. Just like the rest of the wall, for an old building all your tuckpointing should be with soft mortar, preferably test the mortar for composition but no one in our market wants to do that, even DOD projects, but we still recommend it

 

[bones206]

EngineeringEric - if it's not too much trouble, could you elaborate on the merits of soft mortar vs grout for this application? Is it a concern with reactive material interaction? Thanks

 

[phamENG]

Eric - agree 100% on the mortar for repointing. Do you guys handle testing during design, or put it off on the contractor? I've only seen the latter around here, but have been working toward the former as my historic portfolio is growing. Just haven't found a reliable lab here locally with experience in the historic testing - petrography, acid dissolution, etc.

 

[EngineeringEric]

Well now that I can say I have numerous offices with different services, we do it. It isn't that expensive when part of a bigger project. We have to ship a few chunks of mortar to our lab in Cincinnati. We often include it in our proposal as a recommended line item and have the discussion of the benefits of doing it now vs letting the GC do it... and it is rarely awarded to us unless the owner fully understands historic masonry. so 95% it is put off on the contractor who proposes using a cement-lime type O/N. I think we've used a K-type before but not for a taller structure.

Your Geotech friends who are my colleagues may know of a different option or you could reach out to one of the contractors who do this work, I'm sure we both have preferences in that field.

 

[XR250]

Why do you need a sleeve at all? How about just caulking around the lines?
AS KF said, the coring is really clean.

 

[phamENG]

Indeed - I was afraid you'd have one "in house."

Most of the good historic masons have been retiring, so I'm encountering more and more bags of portland based masonry cements on job sites. Too many charge forward without even telling me they're going into construction much less submitting anything for review. I'd rather just get it done myself and provide it as part of my design. I'm sure it'll be an uphill battle, but so be it.

 

[phamENG]

XR - my concern is hitting some of those soft salmon bricks or other junk inside the wall. I also want to make sure any exposed brick surfaces are adequately "sealed" to moisture and freeze/thaw

 

[EngineeringEric]

what battle isn't uphill in our line?! I shouldn't smile typing that as much as I should cry but so be it.

There are a few larger companies that do good work around here. Richmond Primoid usually does good work in our experience and for smaller projects (house size) there are some great smaller contractors. But we also run into those who use whatever sack mix Home Depot has on sale.

 

[MRob909]

In the UK we encounter this quite frequently. The general route we go down is to specify a core hole using a diamond tipped core. This leaves a very neat hole which can be slightly oversized for your service sleeve. The key thing is to ensure the Contractor doesn't use 'hammer mode' on the drill and goes slowly through the brick. A resin suitable for masonry around the sleeve (Hilti, Rawl etc.) has worked well in the past.

 

[phamENG]

MRob909 - thanks. I appreciate the insight from your side of the world. Our historic buildings are your standard building stock, so your opinion is certainly valuable.