Matching existing mortar - sandy consistency

Reply

  #1  
Old 05-08-19, 01:27 PM
Member
Thread Starter
Join Date: May 2019
Location: United States
Posts: 4
Matching existing mortar - sandy consistency

My house was built in 1959, and I'm working on some mortar issues, and would love to match the mortar originally used on the house. The mortar used from the big-box store is completely uniform gray, but the mortar on my house looks very sandy. Please see the attached picture. You can see where someone redid some brick back in 1985 when they took out a window and put in a door. The mortar looks completely different.

What can I do to get something that more closely resembles the original?

THANKS!
/b
 
Attached Images  
Sponsored Links
  #2  
Old 05-08-19, 02:34 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 45,523
Likes Received: 47
The premixed mortar uses white sand, it looks like your mortar was a coarse brown sand. Not sure if you can get sand to duplicate the coarse but using 3 parts brown sand and 1 part mortar should get you close to the right color.
 
  #3  
Old 05-08-19, 02:41 PM
Member
Thread Starter
Join Date: May 2019
Location: United States
Posts: 4
Thanks, one more question...
This is what the light colored stuff is (picture)... Are you saying add sand to that?
Or are you saying mix my own mortar (portland, etc)? - because I have no idea how to do that...
 
Attached Images  
  #4  
Old 05-08-19, 02:53 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 45,523
Likes Received: 47
The premixed mortar uses white sand - that is why it's grey. You need to use mortar [not premixed] and mix in 3 parts sand. That is basically what the premix is except you want to use brown sand instead of white sand. The mortar and sand measurements don't have to be exact. For small amounts you'd use 1 shovel full of mortar and 3 shovel fulls of sand .... or whatever amount works best for what you need. Portland is too strong, mortar is better.
 
  #5  
Old 05-08-19, 03:07 PM
Member
Thread Starter
Join Date: May 2019
Location: United States
Posts: 4
Man, I really appreciate your help. Could you give me the name of a product I should buy? I'm looking online at all the big box stores and trying to find "mortar" and I'm only seeing "Mortar Mix"... Sand I can find, it's the mortar I'm unsure about... Hate to bother you with this. Thanks!
 
  #6  
Old 05-08-19, 04:07 PM
Member
Join Date: Jan 2013
Location: U.S.A.
Posts: 1,828
Likes Received: 29
I cannot give you a specific product, but can say that Mark is right on. You may need to visit a yard rather than a big box, and you may need to play around with it a bit to figure how much brown sand you want to each unit of mortar, but it's doable.
 
  #7  
Old 05-09-19, 03:31 AM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 45,523
Likes Received: 47
I never pay much attention to the brand. You should be able to buy it at a big box store along with any place that sells block or brick. Here is an example from Lowes - https://www.lowes.com/pd/Sakrete-70-...ement/50062541
 
  #8  
Old 05-09-19, 04:55 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 20,100
Likes Received: 106
There are articles and videos online about matching mortar. I suggest you do some reading and watching. It's an art and depends on blending the right ingredients in the correct proportions. There is no formula and there is no "go buy this brand". You will be baking from scratch and will add ingredients and tweek until you get the desired result. You'll probably need portland cement or sandless mortar mix, lime and the proper sand. I once knew a mason who had about 20 different kinds of sand in his shed that he had collected over the years specifically for matching old mortars.
 
  #9  
Old 05-10-19, 09:25 AM
Member
Thread Starter
Join Date: May 2019
Location: United States
Posts: 4
Thank you all! I deeply appreciate the help. I'm just trying to get closer than what was done before, which really stands out.
I plan on buying a few types of sand, and the following (It says cement, but appears to be same as what was recommended):
https://www.homedepot.com/p/Quikrete...2570/100318484
 
  #10  
Old 05-10-19, 11:11 AM
Member
Join Date: Nov 2012
Location: USA
Posts: 1,165
Likes Received: 11


That mortar would have been a uniform tan for the first few decades, you're only seeing the sand color coming through because the surface mortar wears away over the decades (isn't a problem if the mortar is good.)


Your problem is that the 1959 mortar is (almost certainly) a custom mix made up in batches by whichever masons did the brickwork. Looks almost like beach sand and tan mortar. Good news is they would probably have bought local sand a few tons at a time, along with bags of lime. Other good news is that they likely used the classic (roman engineering manual of Vetruvius) mortar ration of 3 parts washed sand to 1 part slaked lime/ lime putty.

You will NOT match that color or texture starting with pre-made big-box-store concrete mixes. You actually do NOT want bix box store concrete mix, you likely want a "classic" sand-lime mortar mix.
I'd start by checking there are any "historic architecture tours" in your area, ask about matching old mortar.

Next lead would be checking the current list of local masonry contractors, and then checking against old phone books / old local newspapers to see which local masonry business has been around the longest. Call em up, tell him you're looking for somebody with enough experience to color match a 60 year old mortar recipe, offer to treat their oldest mason to a really nice lunch or early dinner if they can figure out what the mix is.
 
  #11  
Old 05-11-19, 02:59 AM
Member
Join Date: Oct 2001
Location: USA
Posts: 919
Likes Received: 1
Hal S is correct, that old mortar surface has been worn off after years of exposure. It's almost like a very small exposed aggregate surface like what's used in concrete flatwork. If it were mine, I'd buy a few cheap bricks and lay them up with your mortar experiments. Then, just like an exposed aggregate sidewalk, gently wash and lightly scrub the surface to expose the aggregate in the mortar. I'v never done it, but I really think it's worth a shot. Do some research on exposed aggregate concrete (without using a surface retarder) to see what the technique is when using just water.
 
  #12  
Old 05-11-19, 06:11 AM
Member
Join Date: Nov 2012
Location: USA
Posts: 1,165
Likes Received: 11
Those are standard "brush finished" mortar joints. (You use a long narrow brush to pack in and remove the excess mortar)

The OP can match the "exposed aggregate" look for a brushed joint by letting the mortar dry until damp, THEN dabbing/rinsing the damp mortar with a wet sponge to get the surface layer of lime off. This will create a light haze of mortar on the brick face, so after the mortar dries, you need to do a quick rinse with dilute muriatic acid to remove the haze, then wash down the wall with water to remove any leftover acid, the result is an expose aggregate joint.

If you need to touch up drips or splashes of mortar in a few places, just cut 8" circles from a cardboard box and use that like an abrasive wheel- cardboard is too soft to scratch normal brick, but just abrasive enough to remove a thin layer of mortar.
 

Last edited by Hal_S; 05-11-19 at 07:03 AM.
  #13  
Old 05-11-19, 07:12 PM
Member
Join Date: Jul 2003
Location: California
Posts: 1,782
I doubt if this is lime mortar but it could be a lime/white Portland mix or white masonry mix. Experiment, have fun. Try to get some samples of the different cements and lime if it is Portland cement just so you don't have a bunch of 70# and 94# and 50 # bags with only a little removed from them,
The advice to talk to old timers is good. Some will tell you more than you want to know and some will brush you off. Also if there is a firm that specializes in tuckpointing they know what you want to know but to do this yourself is hurting them. Masons on the other hand should not be threatened by someone pointing up a little mortar.
What does the mortar between bricks do? Does it hold the bricks together or hold them apart?
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes