mortar bag for grouting exterior stone wall


Old 12-12-08, 04:43 PM
Thread Starter
Join Date: Dec 2008
Location: NC
Posts: 1
mortar bag for grouting exterior stone wall

Hey, I am new to this site. I have just completed applying stone to an addition to my house onto unfinished concrete wall. Now I am trying to grout between the stones, today I spent several hours on 1/2 bag and got almost nowhere. Is there some trick to the grout mixture? I finally got rid of metal tip, and cut a little more off the tip. This is almost impossible to grout the stone. Help
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Old 12-12-08, 04:59 PM
Join Date: Aug 2000
Location: USA
Posts: 15,834
How did you install the stone? Metal lathe and scratch coat? Did you use mortar between stones as you installed them? Is there a foundation upon which you installed the stone?

Typically, mortar mix is a combination of masonry cement and sand; Portland cement, masonry cement and sand; or Portland cement, lime, and sand. Whatever mix you decide upon can be used for scratch coat, for application of stone, and for grouting the joints. When grouting, you fill a grout bag with mortar, and squeeze like you would an icing bag when decorating a cake, partially filling the joints. Then, you use a striking tool to strike out excess mortar. Finally, you use a whisk broom to whisk away any loose mortar or mortar on stones. Do NOT allow loose mortar or mortar on stones to set up.
Old 12-12-08, 06:15 PM
Join Date: Mar 2006
Location: Austin, TX
Posts: 1,405
There are several tricks. The first one, you seem to have discovered: Make the hole in the tip larger. It should be slightly larger than the joint. That is, for 3/8" joints, the tip should be about a 1/2".

The second and most important trick is to mix the mortar drier than you would think. The wetter it is, the more that the sand in the mortar will "pack" at the tip. If you can't squeeze it out, then it is too wet. Add more dry mortar and re-mix until it squirts out readily.

The third tip is to fill the bag with a comfortable amount of mortar, certainly less than half full. Hold the bag big-side up over the mortar and scoop in a comfortable amount. Grasp the bag at the base of the mortar (to squeeze the air out of the top), then twist the empty part of the bag closed. It should be at least a full twist, if not a little more.

To grout, hold the nose of the bag with your fine motor skills hand and the twisted rear end with your power hand. To extrude the mortar do not SQUEEZE the bag, twist the tail.

Overfill the joints, but DO NOT mess with the mortar! Just get it in the joint, and leave it alone. After the water has been absorbed from the mortar (it will be slightly crumbly and will NOT smear), tool the joints, again not worrying about excess mortar. If any moisture appears on the surface as you tool, it is too early.

After the joints are tooled, use a soft brush to brush away excess mortar. Then let it sit for a while longer. If it is real stone or brick, use a wire brush to clean the edges further. Again, if the mortar shows moisture or smears, wait some more.

As a rule, I will grout 10 Sq Ft, then go back and begin tooling where I stared grouting, then grout 10 more SqFt, then go back and soft brush, then tool the second 10 SqFt, then wire brush the first.

You can not give a time frame, since different materials and environments have different rates of set. Just pay attention to the mortar and do no mess with it too early.

Of course if you mess around and wait too long, then you are screwed. There is a reason tuckpointing costs a lot of money.
Old 12-13-08, 12:38 AM
Join Date: Dec 2008
Location: lancaster
Posts: 193
Don't know what your using for mortar. If it hadeware store bought throw it out But that counld change the color. Bag grouting is fast. Our last big job grouting was over 5 miles of mortar joints. Now that you cut the tip thats good for stone grouting. If you are using sand and cement you mix togther, make sure the sand if free of debris and sand can matter. When we point we mix real runny it almost drips out of the bag. We use portland cement. Lime and sad. We mix very rich for two reasons. One is if you water down the mortar to much it losses some of its strenght. So we go heaver on the portland cement. Now you can use keystone light or keystone high strength mortar and it has the lime in it. If you sre using a re mix color mortar use a little more on the bag end to sand ratio. Mix that about 1 part mortar to 1 1/2 part sand. If the sand seperates in the bag after you squeez it awhile the mix is to light in the cement part it seperating from the sand. watch on letting the mortar staining the cultured stone. For deep fills we partially grout and come backto it and regrout again. be careful when you tool it. to wet in one area tolled will bring the lime to the surface and change the color shade.
Old 12-13-08, 06:27 AM
Join Date: Mar 2006
Location: Austin, TX
Posts: 1,405
21boat, you need to do some reading on mortar. Start here:

Read tech notes 8 and 8b.

You are giving bad advice and performing shoddy work.

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