Would you agree that mortars and grouts matter to a successful tile installation project? And that you need them to be properly mixed?
Having witnessed what can happen when mortars and grouts aren't properly mixed, here are six steps worth considering for success, ranging from using the right tools to following the appropriate product specifications.
Six Steps for Mixing Mortars and Grouts
Step 1: Follow Mortar and Grout Manufacturer Mixing Instructions
Never assume you know everything when it comes to mortar and grout.
Setting tile has become increasingly complex as tile sizes have changed, becoming bigger and longer, and materials have become more exacting in their requirements.
For that reason, the person mixing mortars and grouts should always follow the manufacturer’s guidelines which include water quantity, quality, and temperature, as well as the speed of the mixing motor, normally about three hundred rpm.
This is critical!
Step 2: Beware Low Mixing Speeds
Speed matters. Speeds lower than 300 can lead to ineffective and incomplete mixing while speeds above this recommendation can whip or entrain air into the mix.
Too much air makes the mortar or grout light and fluffy which significantly reduces the product’s strength meaning that the thinset mortar may not adequately bond to the tile or the grout may become soft and powdery.
Neither scenario is acceptable: keep to the correct mixing speed.
Step 3: Allot the Right Amount of Time for Mixing
Mixing mortars and grouts includes three phases:
- The initial mix
Equally important is allotting the right amount of time to each of these three phases.
The initial mix thoroughly blends all of the product ingredients.
Slaking allows those materials to rest in the bucket.
Finally, remixing ensures that the mortar or grout has reached an optimal state for your tile installation project.
Don't rush; follow the time guidelines.
Step 4: Use the Correct Mortar and Grout Mixing Paddle
The right tools matter for installing tile, and you'll find numerous configurations when it comes to mixing paddles. Basically, the assortment available from the tile distributor, box store, or the internet consists of three models as seen above from left to right; the box mixer, the beater, and two styles of the spiral mixer.
The beater has been around a long time and looks somewhat like a larger version of the kitchen mixer used to mix cookie dough and cake batters.
It does a good job of blending the ingredients while not whipping (entraining) excess air into the mix.
The Spiral Mixer
The spiral mixer has gained popularity due to its ability to thoroughly blend the mix from the outside of the bucket to the inside without adding additional air.
You'll find different styles available as you see in the image.
Step 5: Avoid the Box Mixer
Stay away from box mixers; they aren't effective for tiling.
Originally designed to quickly mix drywall mud, the box mixer moves mud from the inside to the outside of the bucket and in doing so, mixes a large volume of air.
This is where the double whammy comes into play. If you mix with a motor that spins faster than the recommended 300 rpm speed, you whip air into the mortar or grout. Add the results of excess speed to that of the box mixer and you have an extremely weak product.
One other feature of this paddle is that not only does it throw the mortar to the outside of the bucket; it does a great job of also throwing it all over you from the knees down.
Step 6: Consider a Dust Containment Device
Also when mixing, you might consider using a dust containment device that attaches to the rim of the bucket and a HEPA-filtered vacuum.
This combination eliminates just about all of the dust involved in the mixing process, a wise choice which protects the health of the person doing the mixing while providing a clean work space.
Do You Follow these 6 Steps for Mixing Mortars and Grouts?
Are there others you'd include in this list?
Consider becoming a Certified Tile Installer if you aren't already. As a CTI, you set yourself apart from the crowd and know how to anticipate tile installation problems before they occur.
Thanks for reading.