Pressure Sensitive vs Wet Set Adhesives: What's the Difference?

When installing resilient flooring, choosing the right adhesive is just as important as selecting the floor covering itself. However, it's not only the adhesive that matters – it's also how it's designed to be used.

Two common methods you'll come across are pressure sensitive and wet set adhesives. While both provide a secure bond when used correctly, they work differently and are intended for different flooring applications.

Ardex offers solutions for both resilient flooring and carpet tile installations. Ardex AF145 can be used as either a pressure sensitive or wet set adhesive for vinyl floor coverings, while Ardex AF825 is a pressure-sensitive surface tackifier designed specifically for carpet tiles and selected underlays.

Understanding the differences between these products and installation methods can help you choose the right solution for your next flooring project.

What Is a Pressure Sensitive Adhesive?

A pressure sensitive adhesive is allowed to dry until it becomes tacky before the floor covering is installed. Once the adhesive reaches the correct stage, the flooring is laid into position and rolled to achieve a secure bond.

This installation method is commonly used with luxury vinyl tiles (LVT) because the tacky adhesive helps prevent planks and tiles from moving during installation, making accurate positioning easier.

Pressure sensitive adhesives also provide installers with a longer installation window, allowing larger areas to be completed before additional adhesive needs to be applied.

What Is a Wet Set Adhesive?

With the wet set method, the floor covering is installed into the adhesive while it is still wet, following a short airing period.

As the flooring is laid, the adhesive transfers directly onto the backing of the floor covering before curing to form a strong bond.

Wet set installation is commonly used for sheet vinyl and can also be suitable for certain vinyl tile and plank installations where recommended by both the flooring and adhesive manufacturers.

Ardex AF145 – Two Installation Methods in One Adhesive

One of the key benefits of Ardex AF145 is its versatility. Unlike many flooring adhesives, it can be used as either a pressure sensitive or wet set adhesive, making it suitable for a wide range of resilient flooring installations.

Suitable for luxury vinyl tiles, vinyl planks, vinyl tiles and sheet vinyl, AF145 gives installers the flexibility to select the installation method that best suits the floor covering and site conditions.

Using AF145 as a Pressure Sensitive Adhesive

When installing as a pressure sensitive adhesive:

• Airing time: 20–40 minutes
• Working time: Up to 30 minutes for LVT
• Up to 80 minutes for sheet vinyl
• Open time: Up to 100 minutes

The tacky adhesive film helps keep tiles and planks in position during installation, making it particularly suitable for LVT.

Using AF145 as a Wet Set Adhesive

When installing as a wet set adhesive:

• Airing time: 5–20 minutes
• Working time: Up to 45 minutes
• Open time: Up to 50 minutes

This shorter airing time allows installation to begin sooner and is commonly used where a wet set application is recommended by the floor covering manufacturer.

Ardex AF825 – A Pressure-Sensitive Tackifier

Although AF145 can be used as a pressure sensitive adhesive, Ardex AF825 has been developed for a different purpose.

AF825 is a pressure-sensitive surface tackifier designed for installing carpet tiles and selected underlays. Rather than creating a permanent wet bond, it dries to leave a permanently tacky film, allowing individual carpet tiles to be lifted and replaced without disturbing adjacent tiles.

This makes AF825 particularly suitable for commercial environments such as offices, schools and retail spaces where damaged carpet tiles may need replacing during the life of the floor.

Key features include:

• Pressure-sensitive surface tackifier.
• Suitable for carpet tiles and selected underlays.
• Floor coverings can be installed from 10 minutes, or up to 24 hours after application.
• Allows individual carpet tiles to be removed and replaced easily.
• Suitable for raised access flooring.
• Suitable for use over underfloor heating.
• Coverage of up to 125m² per 10kg tub.

Which Product Should You Choose?

Choosing the right adhesive depends on the type of flooring you're installing.

Product	Best For
Ardex AF145	LVT, vinyl planks, vinyl tiles and sheet vinyl where pressure sensitive or wet set installation is required.
Ardex AF825	Carpet tiles and selected underlays where a pressure-sensitive tackifier is required.

Always follow both the flooring manufacturer's installation guidance and the Ardex Technical Data Sheet to ensure compatibility and achieve the best possible installation.

Final Thoughts

Pressure sensitive and wet set adhesives each have their place in modern flooring installations. Understanding how each method works allows you to choose the most suitable product for the flooring being installed.

For resilient flooring such as LVT and vinyl, Ardex AF145 provides the flexibility of both pressure sensitive and wet set installation methods within a single adhesive. For carpet tile installations, Ardex AF825 offers a pressure-sensitive tackifier that allows individual tiles to be removed and replaced with ease.

At Floormart, we stock a wide range of Ardex flooring adhesives to suit commercial and domestic flooring projects. Whether you're installing LVT, sheet vinyl or carpet tiles, our team can help you find the right adhesive for your application.