Mixing Repair Mortars

April 4, 2009 By
Repair Mortar… How to Mix It –  Are you ready to start your mortar and stucco repair projects around your home or business?  If so, let me show you how to minimize your problems when you begin to mix your repair mortar and how to ‘temper’ it (keep it workable) as you continue with your work.
If you follow these tips your mortar repair chores will be much easier and can be an enjoyable and rewarding experience!These tips are for use with the ready made repair mortars that are sold at your local building supply center.  They are available under many name brands including Quikrete and Sackrete.
Product – Try to find a commercial grade mason’s mix if you can.  It is available in many parts of the country and is a premium product.  Since it contains more cement as well as other additives, it is a little ‘fatter’ and easier to work with.  If you cannot find the commercial grade mortar in stock then pick up a bag of regular masons mortar mix which can be used as well.
Mixing Tools – Since most of your repairs will be small to begin with, you will not need a large mixing container.  In fact a large plastic bowl, of a gallon size or a small bucket, will work just fine.  While you are at the store pick up a small 5” x 2” margin trowel for mixing and have a small bucket of water with a cup, available as well.
Mixing – Now open up your mortar bag and fill the bowl or bucket half way with the mortar mix.  Pour some water into the bowl until you cover your mortar well and begin to mix.

As you mix, pull up and turn over the mortar.  At first it will dry out quickly so just add little more water and continue to mix.  Eventually you will notice the mix ‘smoothing out’ which means the clumps are separating you are close to finishing the mixing process.  Here is where you need to pay the most attention.

What you are looking for is a stiff batter like consistency.  The amount of water that you use will vary with the temperature and humidity.  If it is hotter then more water will be needed… cooler, less.  This whole process shouldn’t take any more than about 5 minutes to complete.

As you get closer and closer to the final mix consistency be careful not to add too much water, as this will make the mix wet and runny.  If that has already happened don’t worry, just add a little more dry mix to stiffen it up.

Checking the Consistency of the Mix – After you have completely mixed the mortar in your container, take your trowel and insert your blade in the mortar approximately 11/2” deep and at about a 90 degree angle to the surface.  Now drag the trowel across the surface of the mortar from one side of the container to the other.

If the consistency is right you should see a well defined and smooth furrow in the mortar.  The furrow walls should not have ‘slumped’ down as you moved your blade through the mix.  If the consistency is too wet then the furrow walls will slump back into the furrow and you possibly will see water in it as well.

If the mix is too dry it will tend to ‘pull’ and ‘ball’ the mortar along the furrow walls like it is being pulled away from the sides of the furrow.  Temper the mix with water until you get the right consistency.

Let the Mix Set – Now I want you to step away and let the mortar ‘set’ for about 10 minutes.  This will allow the initial hydration ‘kick’ to take place so you can quickly temper the mortar before you begin to work.

It better to wait a few minutes then to get to where you are working and find the mix beginning to harden as you are starting to work on your repair.  In addition, this first ‘temper’ tends to increase the ‘workability time’ of the mortar which makes it a little easier on you especially when it is warm.

If it is chilly out the mortar probably won’t change much, if at all in 10 minutes.  If it is warm then you will notice that the mortar has stiffen somewhat.  Add just a small bit of water to the mix again and ‘temper’ or mix again to the right consistency.

Check your mortar frequently and maintain its’ workability but adding small amounts of water.  With practice and practice you will come to know just how long your mortar will last and any given day depending on temperature and humidity.  Have fun and good luck with your chores!

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