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-   -   Uh Oh - No Sand in mortar (http://www.diychatroom.com/f105/uh-oh-no-sand-mortar-127401/)

Seriak 12-22-2011 01:52 PM

Uh Oh - No Sand in mortar
 
Okay, I am an extreme DIYer. I try to do everything myself. So here is my dilemma. I finished off my scratch coat on a brick veneer wall that I am doing. However, I thought I got the premix with mortar and sand but it turns out that I just got the mortar mix. Do I need to start hammering all the scratch coat out and if so, what is the best way to get it out of the lath. I don't want to completely destroy the drywall behind it.

Any advice?

Arkitexas 12-22-2011 02:36 PM

Leave it alone.

The sand in mortar performs two functions. First, silica sand, being less expensive than cement, inexpensively expands the volume of the mortar. With an optimum amount of sand in the mix, the cement still functions as workable paste (mortar). The sand is as strong as the cement and the cement bonds readily to it to form a homogenous material when set. Second, since sand is a solid and does not shrink during the curing process, it reduces the amount of overall shrinkage of the cement and thus minimizes cracking during the curing process. Omitting the sand may produce hairline shrinkage cracks but is not detrimental to the strength or usefulness of the mortar.

To sum up, because the scratch coat is covered by the masonry veneer, any shrinkage cracks will not be visible.

Rick

paul100 12-23-2011 11:30 PM

I think what the Op is saying is that he bought what is called masonry cement. It is a premix of cement and lime. You need to add your own sand. I do not know how well it will hold up without adding any sand to it.

jomama45 12-24-2011 09:37 AM

Take a picture of the bag of mortar/cement you used and post it here if in doubt......

Daniel Holzman 12-24-2011 10:14 AM

I think the confusion is the wording of the post. The definition of mortar is a mixture of sand, water, and binding agent (cement). The oldest mixture for mortar I am familiar with is Vituvius of Rome, who came up with the mixture of one part sand, one part water, and one part lime, a mixture still used, and known as lime mortar.

More modern mortar substitutes portland cement for lime, a mixture known as portland cement mortar. So the question is, what did the OPS actually buy? If the OPS purchased mortar cement, that could be lime, it could be portland cement, or it could be a mixture, but it is not mortar. How well cement only would hold up is beyond my knowledge.

joed 12-24-2011 11:02 AM

If you used mortar MIX then you are fine. It is premixed and ready to use. If you just got mortar cement then I would be surprised if is even hard. It probably dried but It will be very soft and come off the wall easily.

Seriak 04-24-2012 03:12 PM

Oh wow, I had more replies and my email verification didn't work. The project got put on hold, so I haven't done anything with it yet. The mortar I used was Quikrete where is says to do the following.

QUIKRETE & LAFARGE MCS Cement Type Mortar S is the basic ingredient to be mixed with masonry sand for making Type S mortar. To be used for laying of brick, block, stucco and other masonry applications
  • Greater bond over Type N Mortars
  • No need to add lime
  • See chart for mix ratios
I did not add the sand to my scratch coat. It is very hard, but it does crumble easily where the lath is not present. Should I start over or will the lath hold it together.

joed 04-24-2012 05:20 PM

What you had there is actual mortar not mortar MIX. It should have been mixed with sand. I don't know how it will standup.


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