How to Make Thinset Mortar

Use thinset mortar to hold tile to vertical or horizontal surfaces.

Thinset mortar comes premade or in a dry mix and is used to adhere tiles to floors or walls. For the true do-it-yourselfer who wants to control every aspect of his remodel, thinset dry mix allows you to make your own thinset to your desired consistency. However, you have to be careful of over- or under-watering the mortar. The strength of the mortar is proportional to the amount of water in the mix. Too dry and the tiles will not stick to the floor; too wet and the tiles will pop off as the floor ages.

Things You'll Need

• 3 - 5-gal. buckets
• Thinset dry mix
• Mixing paddle
• Electric drill, 14-volt or larger
• Safety goggles
• Dust mask

Instructions

1. Gather three clean 5-gal. buckets for mixing.

2. Fill one bucket with water for cleaning your tools and one with the manufacturer's recommended amount of water for the thinset mortar.

3. Add half the manufacture-recommended amount of water to the third bucket.

4. Add all the thinset dry mix to the bucket. Pour carefully and as near the bucket as possible to avoid creating clouds of mortar dust.

5. Pour one-quarter of the remaining manufacturer's amount of water on top of the mortar mix.

6. Attach a mixing paddle to a 14-volt or higher electric drill. Do not use a battery-powered drill. Once the mortar begins to thicken, the motor will not be strong enough to mix the mortar.

7. Insert the mixing paddle to the bottom of the mortar bucket and start the drill on high speed. After you thoroughly incorporate the dry mix, increase the speed of the drill to mix the mortar.

8. Add the remaining water in small amounts as needed. The final consistency of the mortar should be like thick pudding or creamy peanut butter. If the mortar is thin enough to pour, you have added too much water and will need to add some dry mix to compensate. If the mortar is like chunky peanut butter or crumbles, you need to add more water.

9. Remove the paddle from the mortar and scrape off as much as possible with a trowel.

10. Insert the mixing paddle into the bucket containing the clean water and turn the drill on low speed to wash off the mortar. Do not delay. If the mortar dries on the paddle, it will be impossible to remove without damaging the paddle.

Tips & Warnings

• Only make as much thinset mortar as you can use in 30 minutes to one hour. Thinset begins to cure as soon as it is mixed and trying to rehydrate mortar in the bucket can result in poor adhesive properties or a soupy mess.

• Mortar mix contains Portland cement and lime, both of which are irritants to eyes, nose and lungs. Wear protective goggles and a dust mask when mixing mortar.

References

• BathroomFlooringIdeas.com; How to Properly Mix Thin Set Mortar for Great Results; Jim Bessey