mortor mixing

by Todd
(Dothan, alabama, usa)

I am curious about the mortor being used in the video where you are laying the 12's. What type is it and what are the mixture ratios. We haven't been able to get our mortar that consistent and it seems to be very smooth.


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Aug 01, 2011
The main ingredient
by: F.J.N.

The largest component of mortar is sand. It goes without saying it better be right.Aside from the correct volume if you want workable mortar the gradation of sand particles must not be to fine or to coarse!The ASTM standard C144 governs sand for mortar.The closer one can hit the ideal range for % of sand passing each siev the better off you are.Here are the siev sizes along with the ideal % passing. #4 100 #8 97 #16 84 #30 50 #50 27 #100 6. Most sand sold as mason sand is way way to fine. Get some sand that passes these specs and you will be using some of the best mortar that ever touched your trowel!Also to help you get your ratio of cementious material& sand right read the great posting by Gerard Lynch THE MYTH OF THE MIX. Have fun!

Jul 31, 2011
Plasticity/workability of mortar
by: F.J.N.

The plasticity and workability of mortar are synonymous. The ability of mortar to possess these qualities depend on several factors. probably the most important factors are the ratio of cementious materials ( cement & lime)to sand.Along with the proper ratio the correct gradation of sand is imperative. Lime imparts manny positive . Among these are plasticity, water retension,autogenious healing,longer board life,improved tensile bond strength between masonry units.The more lime the more of those qualities.Most of our mortars spected today suffer from to much compression strength (to brittle mortar).To learn way more read the superb book by michael wingate Building with lime. You will be extremely glad you did.

Mar 15, 2010
Mortar Mixing

I have used a similar mix as you are talking about, but this is what the mix I have used consists of;

* 1 part Cement powder
* 3 parts sand
* 1/2 part lime

The water is usually not consistent because of the different sizes of aggregates in the sand so you have to add the amount you like to make your mortar easy to use.

This mix is really close to a 2800 psi mortar, so it is considered type S

To make Type N just add one more part sand.

I usually measure these out in a 5 gallon bucket.
A half bag of Portland cement will fill a 5 gallon bucket almost to the top so I use that as a part. If you lay the bag of Portland cement over a shovel handle and use a trowel to slice it down the middle of the bag then slowly pick up the shovel pulling the two half's together then rip the shovel through the rest of the bag makes splitting the bag into halves simple.


Mar 04, 2010
premixed mortor
by: Anonymous

the type of mortor we use is premixed minus the water and the sand. we usually put 10 gallons of water and 32 heaping shovel fulls of sand per two 70 pound bags of the mortor. Do you use something similiar sometimes with a different sand and water ratio?

Mar 04, 2010
Mortar Mixing

The mortar used in the video is called spec mix, and on this same project we used quickrete, but the quickrete must be type s which means structural. I have used quickrete that was not this smooth, but an easy solution to that is to add a bit of lime to the batch, yes this does weaken it a little, but not too much if you only use a small amount, for instance one 20 ounce cups for every 80 lb bag of mortar.

Note that the size of the aggregate in the mortar is what makes it smooth or rough, the lime acts as a filler between the larger aggregates thus making it a smoother more sticky mix. Hope this is what you are after.

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