Blue Max® Caulk Crack Repair & Sealant is a thick, blue, elastomeric, waterproofing rubber primarily used as a filler & sealer for masonry, cement backer board, ICF, wood, metal, and EPDM. Fill & seal joints, holes, valleys, cracks, around vents, low spots, flashings & seams up to 5/8" wide
Happy with the results!
Used this to seal up our shower and tub and it worked great!! Was quick and easy to use and am very happy with the results