Question about masonry restoration

   / Question about masonry restoration #1  

HCJtractor

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upstate South Carolina, Greenville
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My 100 year old brick house needs some mortar repair. I know the mortar is unlike the modern Portland cement based mortar, as it is much whiter and softer. I assume it's a lime based mortar common years ago, Having read lots about it, I want to experiment to try to match. I know I can get it analyzed, but I'm cheap. My problem is I can't find a type S hydrated lime. No one around here sells it, nor can I find it online. Quikrete makes this product I assume may be close enough, but it's not available here. Any ideas? Tractor supply sells an Ag lime some say is the same thing. Is that true? My resources tell me to use a hydrated lime.

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   / Question about masonry restoration #2  
You will regret not using mortar. You can color it and it will match and last longer and also keep water out better. I helped do a pre Civil War farm house here in he valley a few years ago. We used 4.5" grinders with 3/8 wide diamond wheels and took out all of the mortar joints and tuck pointed them all back in. The dust and grit wire out the zipper on my carhartt coat. Ed
 
   / Question about masonry restoration #3  
"Some mortar repair" is difficult. There are many places where only a portion of the joints were done and it sticks out like a sore thumb. Although it would be a big job, repointing the whole building would normally look much better.

If I were to undertake such a project I'd seriously consider something like the tool in the link below. It's available for around $200 some places. Of course you'll probably wear out a few shop vacs that will be required to pull the dust away from the tool. But then, your lungs will be in better shape at the end of the project. OSHA has / is developing rules concerning silicates that will both help and handicap people who work with or even disturb masonry (repointing, drilling, cutting, grinding, etc.)

DWE46101 5"/ 6" Cutting & Tuckpointing Dust Shroud Tool Kit | DEWALT Tools
 
   / Question about masonry restoration
  • Thread Starter
#4  
I'm not repointing the house. Most of the joints look good. What I'm doing is moving a few doors and windows, so there will be some very small areas where new mortar is necessary. And from what I've seen and read, new mortar will not match the old, because it's a totally different composition. Most material detailing historic renovations also warn that using modern mortar with old soft brick can lead to issues, but that's not my main concern. I'm mainly concerned that my new patches won't stand out visually. That's why trying to use the original lime mortar formula seems wise. So I'm still looking for a source for hydrated lime.

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   / Question about masonry restoration #5  
I'm not repointing the house. Most of the joints look good. What I'm doing is moving a few doors and windows, so there will be some very small areas where new mortar is necessary. And from what I've seen and read, new mortar will not match the old, because it's a totally different composition. Most material detailing historic renovations also warn that using modern mortar with old soft brick can lead to issues, but that's not my main concern. I'm mainly concerned that my new patches won't stand out visually. That's why trying to use the original lime mortar formula seems wise. So I'm still looking for a source for hydrated lime.

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Good luck but I doubt you will get the match you are looking for, you can't age what you are putting in. I hope I am wrong, but....... Ed
 
   / Question about masonry restoration #6  
I would try to color a current mortar mix to get close to the original appearance. "Back in the day" we would lay brick or tuckpoint with new mortar and then "dust" the brick and mortar with a dirty burlap sack to give it an aged appearance. Amazing how old it looked afterward. You might try experimenting with that approach.
 
   / Question about masonry restoration #7  
I've been a bricklayer for 35 yrs. What we usually use is regular mortar with a light buff coloring mixed with concrete sand(very coarse). Let it set up fairly hard and brush it with a stiff brush. if anything you want the new mortar a little darker than the old so it wont be as noticeable. This works on most of the old houses around this area
 
   / Question about masonry restoration #8  
LOL. I needed to repair some fireplace joints and matching became a challenge.
I ended up cleaning with a detergent and smearing the new joints with the soapy water until they all became the same color.
Nobody could ever detect the repairs.

Another thought is that latex based paints will adhere to mortar joints quite well so once done you can do the artist thing and actually paint the new joints to match. That would be my plan of attack.
 
   / Question about masonry restoration #9  
Many times mortar was made with portland, sand and lime that lightened the color towards white...
A couple of options to making strong white mortar...

Trinity White Portland some "easy spread" and diamond sand etc..
Any exterior (colored "thin-set", tile etc.) mortar sets very hard with minimal shrinkage...
Look into using a masonry bonding agent....

Good Luck...
 
   / Question about masonry restoration #10  
Quikrete makes Type-S hydrated lime, and other sorts of lime products. Ag lime is calcium carbonate, not the same thing, do not use it for mortars. Google Hydrated lime Type-S for more information on Type-S and some other manufacturers.
 
 
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