Lightweight Mortars, What and Why?


Shawn Millman

 January 18, 2021. 10:03 PM

Lightweight mortars are a specialized type of tile mortar, of which MAPEI has an assortment to choose from. Buyers might see these products on the shelves or on our website and wonder why they might venture to use them? Let’s take a look at what makes lightweight mortars so advantageous. 

In general, lightweight mortars are a creamier and easier spreading product than the typical polymer-modified tile mortars. (MAPEI’s new Keraflex™ line - including Keraflex Super, Keraflex Plus, Keraflex SG, and Keraflex RS - is changing the landscape with this regard, but that’s a subject for another day.)

For years now, lightweight mortars have been some of the best handling products we have to offer. When using MAPEI Ultralite S1 Quick, MAPEI Ultralite Mortar, or MAPEI Ultralite Mortar Pro, a large tile will have a surprisingly minimal, or no downward sagging on a wall, upon being set. These products also resist squeezing out from under a large and heavy tile that is installed into a floor. The advantage here is that a tile will stay in-plane with the adjacent tiles, whereas other mortars can sometimes let the tile settle, and sink, moments after setting a tile.

More than 20% recycled content

From a sustainability perspective, the Ultralite mortars have one more trick up their sleeve. These products include post-consumer recycled content in their formulations. For customers who want to make the choices they can to minimize waste and do their part for the environment, Ultralite mortars fit the bill nicely. For consultants and contractors, this means that the Ultralite mortars are formulated with 20% recycled content, with no silica added in the products’ composition. This can contribute to LEED and other green building programs’ credits is certain jurisdictions.

Now let’s take a closer look at how each product stands apart.


MAPEI Ultralite S2
is the “no compromises,” highest performing lightweight mortar for tile that MAPEI has to offer. Although the troweling and ease of use of lightweight products are already enhanced, MAPEI Ultralite S2 is optimized even further, for unmatched ease of troweling, extended open time, and pot life. It has an ISO 13007 classification of C2ES2P2, where the S2 denotes the highest possible rating that can be achieved for deformability. Since the product is tuned for maximum performance, it is a great option for installations that are subject to daily and seasonal structural movement. Large format thin porcelain panels also benefit from such a mortar. The principle behind this is that the mortar can function in some way to compensate between the differences in expansion and contraction that the substrate and tile experience.

MAPEI Ultralite S1 Quick is a mortar that fulfils the need for a product that can accommodate fast-track construction schedules, where grouting can be performed within just three to four hours. Light traffic can be allowed on the floor within six hours, and heavy traffic permitted after just 24 hours.

MAPEI Ultralite Mortar
is the time-tested, most enduring lightweight product that MAPEI manufactures for tile installation. This product has long been a favorite of DIY renovators and professionals. It uses an innovative universal color formula, which means regardless of whether you’re installing earthy-gray marble, or creamy-beige travertine, the same bag can be used for both! MAPEI Ultralite Mortar was originally launched in 2006 as an innovative product in the industry. For jobs where the specifications don’t require the higher performance mortars mentioned above here, it remains a fixture of our product catalog to this day, striking a great balance between performance, price, and ease of use.


MAPEI Ultralite Mortar Pro brings the handling and performance benefits of lightweight products at a professional grade and at a value-optimized price. MAPEI Ultralite Mortar Pro retains much of the performance and sustainability-minded formula of MAPEI Ultralite Mortar, and comes in both gray and white (rather than the universal color formula).

I hope you’ve enjoyed learning about MAPEI’s range of lightweight tile mortars. We hope that you’ll try them on an upcoming project and experience their many benefits for yourself. If you do – or if you have any questions about what you’ve just read - please reach out to us in the comments below. And know that Technical Services (Canada) is always just a phone call away at 1-800-361-9309.


Shawn Millman

Shawn Millman

Shawn is a Regional Technical Representative at MAPEI Inc. and is based at its Delta, British Columbia, facility. He provides technical assistance, training and general advice on all of MAPEI’s product lines to users across western Canada. As a former installer, Shawn combines his field experience with his MAPEI product expertise to offer proactive and enthusiastic insights. Additionally, he is a member of the Terrazzo, Tile & Marble Association of Canada (TTMAC). For his past 12 years with MAPEI, he has applied his experience to the flooring, tile installation and concrete repair industries.


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