A flooring upgrade is one of the most dramatic ways to change a space. But a stunning result is only as good as its preparation. As such, it is no surprise that specific consideration must be given to the substrate, particularly if it is uneven. 

Enter underlayments, which are an effective way to ensure a flooring project is being built atop a suitable surface. Concrete slabs may require additional tooling or smoothing to be flat or level. Instead, self-leveling underlayments (SLUs) may be used with less labor and faster results. As the name implies, these cement- or gypsum-based products are designed to self-level.

SLUs are effective for a variety of spaces and play a formidable role in creating the right foundation—sometimes literally—for flooring projects large and small. For projects where floor weight is an obstacle, manufacturers like Laticrete have gone a step further, creating a lightweight version.

What are Lightweight Underlayments? 

Weight can be problematic both for the building structure and the installer experience. When Laticrete launched NXT Level Plus Lite, a self-leveling, lightweight version of its standard NXT Level Plus, it did so as a means of keeping to structural load specification and giving contractors and installers a product that is easier to carry and handle. Whether the structure is a historic building or new high rise, NXT Level Plus Lite effectively minimizes the impact of weight on the building and installation process.

Up until now, lightweight underlayments have not flowed as well or have not been as easy to place as standard weight SLUs. Greater flowability allows for easy pumping and installation. The challenge with many lightweight SLUs is balancing flow, strength and weight. However, Laticrete has successfully overcome these challenges, achieving high strength and smooth, consistent flow.           

The Old Guard Meets the New 

Projects that now employ an SLU might have previously utilized lightweight concrete, which can take weeks before final flooring installation can begin. Alternatively, early iterations of lightweight SLUs were cumbersome. A lightweight filler would be added to a traditional SLU and placed on the substrate. Once cured, the system would need to be capped with an additional layer of standard weight SLU. This complex, multi-step process often resulted in a weaker underlayment and wasted time. A better product was needed. 

Laticrete introduced NXT Level Plus Lite in 2023, immediately upping the ante for what a lightweight SLU could accomplish. The weight savings were significant. Whereas three inches of standard-weight SLU weighs 32 lbs. per square foot, the same amount of this new lightweight formula came in at just 17.5 lbs. It immediately became a go-to tool for projects with weight considerations at play. 

Installation was also made easier. NXT Level Plus Lite can be poured up to four inches in a single lift. The combination of easy one-step placement and high compressive strength of 4,400 PSI (30 MPa) delivers an unbeatable installation process and superior performance. NXT Level Plus Lite is more than just a lightweight solution. It is an exceptional underlayment that offers high bond and flexural strength. This reduces cracking and enables application over wood substrates without requiring metal lath, saving both time and cost.

Greater flowability allows for easy pumping and installation. Photo: Laticrete.

The Installer Experience 

SLUs like NXT Level Plus Lite are a game changer for installers, touting a significant reduction in packaging weight compared to some other traditional self-leveling underlayments. This translates to easier handling and transportation, which has subsequent benefits of reduced physical strain on installers. 

Project efficiency is improved. Installers can move materials around more quickly and easily, especially in tight spaces or on stairs. Less impact on the installer equates to a lower risk of injuries when carrying heavy loads. Plus, NXT Level Plus Lite is a safer option, with respirable crystalline silica levels well below OSHA's action limit.

Sorting Through the Options 

Finding the right balance between ease of installation, durability, and strength is a key consideration for building projects. Weight concerns add further complications. While most projects can utilize a standard weight SLU, the availability of a high-performing lightweight underlayment now provides a solution for projects with load concerns. Additionally, reduced packaging weight and no respirable crystalline silica levels that exceed the OSHA actionable level offers undeniable benefits to the installer making it easier to carry and safer to handle.

When specifying a lightweight SLU, consider one sourced from a reputable brand. Laticrete provides training and guidance to ensure a successful installation with minimal effort. Though the products used have significant value for the end result, so too does a brand’s expertise.