Need tile advice about thinset - use premixed or mix it myself?

[Louis Brandt]

Hello,

I’m getting ready to tile one of my bathrooms. It will be porcelain tile laid over a concrete floor. My question is, should I use premixed thinset, or should I mix my own? I’m not concerned over the fact that I might get more for my money by mixing my own, I just want to use what’s best for the job. I’ll be laying about 35 12x12 tiles.

Thanks,
Louis

[Jim O'Dell]

I mixed my own for the 1200 sq ft or so that I've laid over the years. I never mix up a complete bag. Just what I think I can use at a time. As you mix, add water until you get the consistency of creamy peanut butter. When you trowel it on, you want the ridges to stay standing up.
I've not looked at the premixed thinset. I did use the premixed mastic for the wall tiles in the 2 bathrooms I did. Hope this helps! Jim.

[Doug W Swanson]

I've mixed my own thinset on all of the tile jobs I've done.....


Doug

[Ken Fitzgerald]

Mix your own. You can mix the amount you can work with in a given amount of timel.

[Dave Ogren]

Mix it from the dry. I am now in the middle of a just under 600 square foot job of slate going down on concrete. I am using the type for marble and granite. It is necessary for slate and costs about twice as much, you don't need this type. I am using a 1/2" x 1/2" notched trowel, I think you only need a 1/4" x 1/4" notched trowel. Using a 50# bag I can get approx 70 square feet done. I only mix about 1/3 of a bag at a time, and can lay about 20 to 25 feet with it by myself in 1/2 hour or just a bit more. I am slow doing this.
Note you should remove any floor or concrete seal that might be on the concrete. A 1/2" drill works great for the mixing. If it is under 50 degrees F. use warm water to mix, makes it mix faster and is easier on the drill. Precut the tiles before you get the thinset mixed up. If you have some left over put the bag into a couple of grocery bags and then put a couple over the top and don't store on the floor and it will still be OK in several years ( moisture is the enemy).
Good luck,

Dave

[keith ouellette]

I would like to add that you may want to use a flexible thin set. It cost more money but I think it is worth it in a bathroom sit. because of the water that could be absorbed by the grout.

[Greg Dykes]

Mapei ultraflex II is one of the best products on the market for this application. Lowe's is a good source. It is best suited for an application where moisture can be a problem. You may not have water problems now but in the future ( toilet overflowing, leak, etc.) you will have oneday.

Using thin set in powder form is the best way to go. A few things to keep in mind:
1. If the thin set starts to harden before you have used it all, do not add water and remix.
2. Following the instructions. With this product you will need to allow it to sit for approx. 10 minutes, remix and then use.
3. Do not use it to thin. For the tiles you are using I would recommend a 3/16" or 1/4" notched trowel.
4. As you are laying your tiles clean the thin set off of them as you go and also clean out the grout joints as you go. It is much harder to do this after it has set. I always use the white colored thin set if the grout color is going to be light. If you use tile spacers while setting the tile, run them along the grout joint to get the excess thin set out. Then use a damp sponge to clean the top of the tile. Most people make the mistake of not cleaning as you go. Before you start laying the tile have a small bucket of water and a sponge beside you and clean each tile as you lay it.

Hope this has helped.