FAQ Knowledge Articles

When installing a Marvin Ultimate Lift and Slide Door (ULS), consider the following information in conjunction with the Site Prep instructions.

Best practices require using self-leveling concrete free of chlorinated additives when installing Ultimate Lift and Slide sills. Calcium chloride is sometimes used as an accelerant for concrete in cold-weather applications. However, it is incompatible with anodized aluminum.

Self-leveling concrete is used to encase and anchor the foundation of the recessed sill in the sub-floor slot. This critical step in the installation process provides a stable sill and track system for door operation. Since the concrete completely surrounds the sill base which is anodized aluminum, it is imperative that the concrete and aluminum are chemically compatible.  


In some applications where sills are more often wet, moisture can infiltrate the concrete and anodized aluminum surface interface increasing the chances of chlorinated compounds in the cement corroding the aluminum.  Avoiding chlorinated additives in the concrete reduces this risk.