Old Chicago brick landing mortar joints
#1
05-02-20, 08:28 PM
Old Chicago brick landing mortar joints
I have an exterior deck with old reclaimed Chicago bricks set on a thick mortar bed probably over 50 years old. A small section of it at one corner probably about 5' by 5' had deteriorated mortar joints. I removed all the loose mortar joints this morning, cleaned it up real good, then I went ahead and put new mortar in the joints this afternoon.
I used Type S stucco/mortar mix. After I filled in all the mortar, I used a sponge to clean the bricks and joints several times.
In the process of cleaning with a sponge, it brings more sand up to the surface. For future reference, is there a way to wipe down the bricks without changing the texture of the joints with all the sand being brought to the surface?
In addition, as I clean the bricks, being these are old Chicago bricks, it has stamped markings on the bricks. as I applied the mortar and clean it the mortar got into these stamped markings. What is a good way to avoid having to come back with a small wire brush to clean out the mortar brick by brick?
After I cleaned the bricks a third time with a sponge, I laid down a sheet of visqueen and weighted that down with a few bricks at the corner so it retains as much moisture as possible and in case it rains (it did rain heavily yesterday). How long should I wait before I can really spray down the are with a garden hose to clean off all the sand? 24 hours? 36 hours or longer?
I used Type S stucco/mortar mix. After I filled in all the mortar, I used a sponge to clean the bricks and joints several times.
In the process of cleaning with a sponge, it brings more sand up to the surface. For future reference, is there a way to wipe down the bricks without changing the texture of the joints with all the sand being brought to the surface?
In addition, as I clean the bricks, being these are old Chicago bricks, it has stamped markings on the bricks. as I applied the mortar and clean it the mortar got into these stamped markings. What is a good way to avoid having to come back with a small wire brush to clean out the mortar brick by brick?
After I cleaned the bricks a third time with a sponge, I laid down a sheet of visqueen and weighted that down with a few bricks at the corner so it retains as much moisture as possible and in case it rains (it did rain heavily yesterday). How long should I wait before I can really spray down the are with a garden hose to clean off all the sand? 24 hours? 36 hours or longer?
#2
05-02-20, 08:47 PM
Group Moderator
Yeah dont get mortar all over the brick in the first place... you have to be careful. After you give it a once over, wait for the mortar to cure. Then scrub with a solution of muriatic acid and protective gear, and rinse it.
#3
05-03-20, 05:14 AM
Group Moderator
As you've found, don't use a damp sponge. You are not grouting tile. The rough face and porous brick will hold the cement (white) part of mortar and leave a stain.
When working with mortar remember that anything it touches will get stained white. So a bit of care up front to keep the mortar off the face of the brick really pays off in the end.
I put enough mortar on the brick so when it's tapped into place it squishes out of the joint. On a horizontal surface I don't don't touch it. I let the mortar sit and firm a bit. Then I strike the joint to the profile I want. Waiting and firming allows the excess mortar scrapped off when dressing the joint to just sit on top of the brick or stone without sticking and making a mark. If the blobs of loose mortar are dry enough you can very lightly broom them away. Otherwise just let them sit where they are and dry/harden some more. Once they are dry they can be broomed off without staining the face of the stone or brick.
If you want a brushed joint I mortar the joint and let it sit. You want the mortar to get quite firm, almost hard. Then use a wire brush to scrub the mortar from the joint. If the mortar sticks to the wire brush let it set longer. When done at the right time the mortar will come off like very slightly damp sand that doesn't stick to anything.
When working with mortar remember that anything it touches will get stained white. So a bit of care up front to keep the mortar off the face of the brick really pays off in the end.
I put enough mortar on the brick so when it's tapped into place it squishes out of the joint. On a horizontal surface I don't don't touch it. I let the mortar sit and firm a bit. Then I strike the joint to the profile I want. Waiting and firming allows the excess mortar scrapped off when dressing the joint to just sit on top of the brick or stone without sticking and making a mark. If the blobs of loose mortar are dry enough you can very lightly broom them away. Otherwise just let them sit where they are and dry/harden some more. Once they are dry they can be broomed off without staining the face of the stone or brick.
If you want a brushed joint I mortar the joint and let it sit. You want the mortar to get quite firm, almost hard. Then use a wire brush to scrub the mortar from the joint. If the mortar sticks to the wire brush let it set longer. When done at the right time the mortar will come off like very slightly damp sand that doesn't stick to anything.
#4
05-03-20, 07:19 PM
Here is a picture of the landing area today.
The area I redid the mortar joints is to the right side, where you see the bricks with a haze of white. If I mist the bricks with water, it will look fine, until it dries then the haze returns. I took a wire brush to brush it good today I think it helped a little, but the white is still there.
I have read that one trick is to use a diluted muriatic acid solution to brush the bricks. However my concern is the one side of this landing is the front gate, the other side of the landing is connected to a wood bridge over a fish pond. I wonder if I use muriatic acid then hose it off it will run into the pond and kill the fish.
I wonder if the haze will wear over time.
The area I redid the mortar joints is to the right side, where you see the bricks with a haze of white. If I mist the bricks with water, it will look fine, until it dries then the haze returns. I took a wire brush to brush it good today I think it helped a little, but the white is still there.
I have read that one trick is to use a diluted muriatic acid solution to brush the bricks. However my concern is the one side of this landing is the front gate, the other side of the landing is connected to a wood bridge over a fish pond. I wonder if I use muriatic acid then hose it off it will run into the pond and kill the fish.
I wonder if the haze will wear over time.
#5
05-04-20, 09:02 AM
Group Moderator
Muriatic acid is really the best way to remove the white haze. Mechanical scrubbing is also possible as you saw but getting it out of the nooks & crannies is very difficult.
Yes, muriatic acid will change the water's pH if it gets into your fish pond. It will lower the pH number making the water more acidic. You can work carefully and hose away from the pond to make sure the acid goes the other way. I would check the pond's pH before doing any acid work and have some pH up chemicals (base) on hand in case you need to correct for any acid that gets into the pond.
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Muriatic (hydrochloric) acid is probably the strongest acid you can just go to the store and buy and is quite hazardous in it's undiluted form. You should read up on safe handling practices and have the appropriate safety gear before beginning work.
Yes, muriatic acid will change the water's pH if it gets into your fish pond. It will lower the pH number making the water more acidic. You can work carefully and hose away from the pond to make sure the acid goes the other way. I would check the pond's pH before doing any acid work and have some pH up chemicals (base) on hand in case you need to correct for any acid that gets into the pond.
---
Muriatic (hydrochloric) acid is probably the strongest acid you can just go to the store and buy and is quite hazardous in it's undiluted form. You should read up on safe handling practices and have the appropriate safety gear before beginning work.
