MasterProtect FL 749: Acrylic copolymer block filler

Formerly: Thoro Block Filler

How does MasterProtect FL 749 work?

MasterProtect FL 749 is a ready-to-use, VOC compliant, 100% copolymer-based block filler resin used to prime and fill porous masonry before the application of MasterProtect coatings.

Recommended uses:

  • Substrates where absorbency is not uniform

What are the unique features of MasterProtect FL 749?

  • Heavy-bodied
  • Breathable
  • Moisture-resistant
  • Excellent workability
  • Moisture tolerant
  • Easy to apply
  • VOC compliant

What are the benefits of MasterProtect FL 749?

  • Fills pores; excellent surface closure
  • Allows substrate moisture vapor to escape from the structure; prevents peeling and blistering
  • Will not degrade in the presence of wet-dry cycles
  • Ease of application; lower labor cost
  • Can be applied to damp substrates
  • Can be sprayed with airless equipment
  • VOC compliant for EPA and most regional authorities

US / Canada Product Information

Data Guide

Data Guide (French)

Data Guide (Spanish)

Certification Letter

LEED Letter

Direct contact

Master Builders Solutions Technical Support

Construction Systems


Safety Data Sheet (SDS)

Find all available safety data sheets for this product.

Product Certifications

Generate a free certificate of conformance for a specific BASF construction product.

Related Literature

Certification Letter

pdf (77.32 Kb)

Data Guide

pdf (93.17 Kb)

LEED Letter

pdf (38.23 Kb)