Ultraflex LFT Rapid

Premium, Rapid-Setting, Large-and-Heavy-Tile Mortar with Polymer

Ultraflex LFT Rapid is a premium, rapid-setting, nonsag, large-and-heavy-tile mortar (formerly known as “medium-bed mortar”) and thin-set mortar for large and heavy tile and stone for interior/exterior floor, wall and countertop installations. This mortar has a high content of unique dry polymer, resulting in excellent adhesion to the substrate and tile. Thanks to MAPEI’s High-Hydrated Cement Technology (HCT), Ultraflex LFT Rapid offers superior drying-out characteristics for quick curing and does not contribute to efflorescence. Ultraflex LFT Rapid is FastTrack Ready, allowing grouting in 3 to 4 hours.

Fast Track Ready
Easy Glide Technology

Technical Data Sheet


Available Colors

00 White


Which tile mortars are recommended for use over Mapelastic® AquaDefense?

MAPEI mortars for use over Mapelastic AquaDefense are: Ultraflex® LFT™, Ultraflex LFT Rapid, Ultraflex LHT®, Keraflex™ Plus, Ultraflex 1, Keraflex SG, Ultraflex LHT SG mixed with Keraply®, Adesilex™ P10 Mosaic & Glass Tile Mortar mixed with Keraply, MAPEI Ultralite™ Mortar and Kerapoxy® 410.

When are fast-curing/rapid-setting tile mortars, such as MAPEI's Rapid Setting Tile Mortar, recommended?

Fast-curing/rapid-setting tile mortars, such as MAPEI's Ultraflex® LFT™ Rapid, are recommended when a quick turnaround is needed. These mortars can be quite helpful for floor-tile projects in homes that have a single exit/entryway or only one bathroom.

Is a polymer-enriched mortar the same thing as a latex-modified mortar?

Yes, there are several terms used to describe a cement-based tile mortar that contains polymer, such as "latex-enriched," "latex-modified," "polymer-enriched" and "polymer-modified." MAPEI's Ultraflex® LFT™ Rapid contains polymer and is considered modified.

Which mortar is best for exterior installations in harsh climates?

A two-component mortar, such as MAPEI's Ultraflex® LFT™ and Ultraflex LFT Rapid, is best for exterior installations in harsh climates, such as those with very hot summers, extreme freeze/thaw zones and seasonally heavy rainfall.

How soon can I apply Mapelastic® AquaDefense over properly taped corners?

After cement board, corners and seams are treated with mesh tape and a polymer-modified, cement-based tile mortar, the area should be allowed to cure for at least 24 hours before application of MAPEI's Mapelastic AquaDefense. Note: If time is an issue, use MAPEI's Ultraflex® LFT™ Rapid with the mesh tape and allow the area to dry for at least 4 hours before applying Mapelastic AquaDefense.