Mastic Vs. Thinset for Shower Walls: Which Adhesive Is Better?

Laying tile for shower walls can be hard work, but you can make it easier if you choose the right adhesive. There are so many tile adhesives on the market these days, but mastic and Thinset mortar are two mainstays when it comes to shower walls. So, what is better; mastic or Thinset for shower walls?

Thinset is better than mastic for shower walls because it can withstand moisture and is more durable. Mastic is easier to use than Thinset, but Thinset is cheaper and more adhesive and can easily stick to tiles. The main downside to Thinset for shower walls is that you have to work fast because it sets quickly.

Thinset mortar is more versatile and has more practical uses than mastic. However, homeowners have used mastic since the 16th century, and that is a testament to how effective it is. Follow along as we compare mastic and Thinset for shower walls.

Mastic is a ceramic adhesive and Thinset is a mortar mix that you can use for shower walls. You can easily apply mastic adhesive to shower tiles when you install shower walls. Popular mastic brands include Liquid Nails which you can easily apply to any surface.

Thinset mortar is a mixture of sand and cement that is similar to Portland cement. There is a water-retention compound within Thinset mortar that helps achieve a consistency that makes it easy to work with. The water-resistant nature of Thinset mortar makes it perfect for moist environments such as a shower.

You can mix Thinset large or small batches depending on the scale of your project. It is easy to mix Thinset mortar, and you can apply it with a trowel. Despite the simple mixture, it is generally easier to work with mastic than Thinset mortar for shower walls.

The main benefit of mastic is that it is easier to work with than Thinset mortar. You can easily readjust tiles while you work with mastic to ensure a perfect fit. It only takes 2-3 days for mastic adhesive to fully cure, but it is mostly cured after 24 hours.

Mastic has been used since the 16th century, and that is because of how strong it is. It is easy to apply mastic evenly and cleanly because of how forgiving it is. The unique texture of mastic comes from tree resin which is what gives it the unique, sticky consistency.

The main downside to mastic is that it isn’t very water-resistant which can be difficult in moist environments. You may lose some of the adhesive qualities of mastic when you install it in a humid or wet area like a shower. Homeowners often use mastic for shower walls, but it is more likely to deteriorate quickly in a humid space.

Unfortunately, moisture is unavoidable in showers and bathrooms. You won’t have a problem if you use mastic in the surround for the shower, but it won’t hold up well within the shower. The only other downside to mastic for shower walls is that it cannot easily support tiles that are 15” or larger because it sets too quickly.

The main benefit of Thinset for shower walls is that it is more durable than mastic. Thinset mortar can withstand moist conditions, and you can even submerge tiles laid with Thinset underwater. That makes Thinset mortar perfect for shower walls and tubs.

You can buy a 60-lb Thinset mortar mix for as little as $5 which makes it more cost-effective than mastic. Thinset is strong and can withstand damage, water, and even foot traffic. That is why Thinset mortar is just as effective for flooring as it is for shower walls.

The main downside of Thinset for shower walls is that it is difficult to work with. Bags of Thinset come ready to use, but Thinset mortar sets so quickly that you must work fast. You can effectively use Thinset for shower walls, but it is best to have someone help you so it goes quickly, or else you may waste mortar.

It takes roughly 48 hours for Thinset mortar to dry, and some tiles may sag during that time. Thinset is less forgiving than mastic and it isn’t easy to adjust a tile once you’ve applied it. You must use all of the Thinset mortar that comes in a bag because it sets so quickly that it becomes unusable.

Mastic is easier to work with than Thinset for shower walls, but Thinset is more effective. Thinset mortar is highly water-resistant and can hold up even if you submerge it in water. However, mastic is not water-resistant and that makes it difficult to work with for showers and bathrooms.

Your tiles are generally fine if you use mastic on a tub surround, but you may have trouble within the shower itself. A 60-pound bag of Thinset mortar mix only costs $5, and that makes it the most cost-effective option.