How to Mix Thin Set

Thin set is an adhesive used to attach tile or stone to a surface. It typically comes in powdered form and needs to be mixed with cool water. The mix is a blend of concrete, sand and additives. Once mixed, the thin set is spread onto the surface with the flat side of a trowel.

Difficulty: Moderate

Instructions

Things You'll Need:

• Heavy-duty drill
• Mortar mixer
• Drop cloth
• 2 buckets
• Thin-set mix

1. Attach a mortar mixer to the drill.

2. Lay out a drop cloth and set a bucket in its center.

3. Fill a second bucket halfway with warm water and set it to the side on the drop cloth. This will be used to clean your mixer or trowel.

4. Add cold water to the empty bucket, between 1 to 2 inches.

5. Pour about half a bag of thin-set mix into the bucket.

6. Position the bucket between your feet, and use your feet to hold the bucket in place.

7. Put the mortar mixer in the bucket and turn it on in short bursts. This will help prevent the mixture from spilling. Do not use a high setting. The drill should be less than 300 revolutions per minute. For a variable speed drill, set at low or medium.

8. Add cool water gradually while stirring. You want the mixture to be sticky wet and not runny.

9. Beat thoroughly, moving the mixer along the sides, bottom, around and up and down, until smooth, creamy and lump-free. It should fall off of the mixer but not run or drip off.

10. Allow the mix to set for 10 minutes.

11. Remix the batch to the consistency it was at the end of Step 9.

Tips & Warnings

• Remix the thin set if the batch begins to harden.
• A less powerful drill might burn out.
• Never add water to the mix after it has rested for 10 minutes.

References

• Mixing Thin-Set Mortar for Tile
• Trowels and Thinset
• Dry-Set Portland Cement Mortar