Modified vs Unmodified Thinset: Which One is Better

Confused about which thinset to choose from for your next house project? We’ve covered this topic extensively in this article. 

Modified vs unmodified thinset? Which one is the winner?

The modified version has latex polymer which increases the durability of the thinset. But, it does cost a bit more. On the flip side, the unmodified version is cheaper but less durable. And who wants less durable materials while building their house? So, we conclude that modified thinset is the better option. Learn more below.

To understand the differences better, dive down below. We have prepared this article explaining thinsets for you. 

Hope you will enjoy it.  

Modified vs Unmodified Thinset – Quick Overview

Usually, unmodified thinset mortar is made of cement, sand, and water retention agents. Which are then mixed by the user with water. 

Modified thinset mortar is like unmodified thinset mortar. The only difference is that modified thinset mortar has extra polymers such as latex. This sort of modified polymer can either be in liquid or powder form. The user can mix the powder thinset with the liquid polymer additive instead of water. Or else, the user can use a premixed thinset and water it. 

Unmodified, this has been used by consumers since 1940. Where the modified thinset mortar has come to the market recently. In comparison to the unmodified version. The modified thinset performs better than the unmodified thinset in general. 

Modified vs Unmodified Thinset – In Depth Overview

The modified and unmodified version has one key difference between them. The difference is the polymer latex which was added to the modified version. 

But when it comes to buying a thinset, there are other factors which go through our heads. These will make sure you will make the right decision.


The price is a huge factor when it comes to purchasing anything. No matter how good a thing is if it’s too expensive, we tend to avoid it. 

Since the modified thinset has an extra ingredient, it is logical to be expensive. But the question is, how expensive? Well, a 50 lbs bag of unmodified thinset can cost you around 50 USD, whereas a bag of premixed 50 lbs modified thinset can cost around 20 USD more. 

Though the price may vary from manufacturer to manufacturer. 


You should consider thinsets durability. Because at the end of the day you don’t want to reconstruct your tiles. 

Unmodified thin-set outdated. People have been using unmodified this since 1940. The unmodified version needs to use in a much thicker layer. Because that makes sure the cement has enough moisture to cure. Otherwise, the thin-set will come off from the subfloor. 

So even if you are using an unmodified thinset, make sure to make a thick layer. 

Surface Compatibility

Adhesives need to apply on a compatible surface for them to perform better. 

The thinset mortar is often chosen. to adhere to ceramic tiles, porcelain tiles, and stone tiles. Though thinset performs best for tiles. Because it creates a tight bond with the surface and stands up to heavyweight. 

To adhere tiles to the subfloor, both the unmodified and modified thinset mortar is used. 

Drying Time

Proper drying is a must when it comes to tiling. Otherwise, the tiles can move from their place and you have to do it all over again. Also, be careful around the door. People can step into the thinset. 

Modified thinset needs less time than unmodified thinset. Because the modified thinset has polymer inside the mixer and contains less water. But still, you should not walk before 12 hours. Also, you should not perform any heavy workload before 7-10 days. 

Modified thinset mortars must dry out to build strength. Do keep in mind that if you’re using Kerdi boards as underlayment, modified thinset mortar isn’t compatible.

An unmodified version of the thinset takes a much longer time to dry because it contains much more water. You should wait at least 12-24 hours before walking over the tiles.

You should also be aware of some common factors about drying timing,

  • Humidity
  • Temperature
  • Airflow in the room

For the thinset mortar to set faster to the floor, you can follow a few more things,

  • Use less water when you mix the thinset
  • Spread the thinset on a dry surface
  • Heat can fasten up the drying process
  • Circulating air around the tiles to maximize airflow
  • Use more polymer for better adhesiveness. 

Ease of Use

Using easier tools and supplies can make any house project less frustrating. 

Unmodified thin sets are less hard to use in comparison to modified thinset. It is because an unmodified thinset requires the user to add water. 

But, the user needs to mix polymer latex to the thinset and mix it along with water. The water and latex ratio needs to be perfect in order for the thinset to perform better. 

The unmodified version can be done in one step, mix, and use. 

So if you are looking for a thinset that is easier to use on your house project, the unmodified version is to look for. 

Which One to Use?

So, all it comes to the final decision. Whether you should buy an unmodified thinset or modified thinset. 

Our opinion is to go with the modified thinset if you are considering a better result. Modified thinset can set your tiles to the subfloor for a long period of time. Also, the drying process is faster in comparison to the unmodified version. 

The drawbacks are, it is a bit more expensive and a little bit tricky to use. But, if you can spare a few more bucks, a modified thinset can bring better results. 

So, we have an unmodified thinset which is less expensive but has its own drawbacks. Unmodified thinset mortar does take a much longer time to dry. Also, unmodified thinset mortar is less durable in comparison to the modified version.

So, if you can get your hands on the modified thinset, go with it!


What are the tools to use to apply thinset?

Tools such as grout float, grout sponge, notched trowel come in handy. These tools will make sure you get your job done. 

How to mix thinset?

The best way to mix your thinset is to follow the package direction. Since the manufacturer can make the procedures different for the mixup. Usually, ½ cup of water for 1 pound of thinset is a good ratio.

How to remove excess thinset from between the tiles?

If it has dried, scrape with a metal scraper, your tiles won’t scratch up. If it’s still wet, use a wet sponge to wipe off the excess thinset. 


So that is all you need to know when you buy a thinset for yourself. Hope that cleared any confusion on the matter. 

Till next time, have a wonderful day.