CMU Waterproofing Question
The contractor wants to use a split face unit for the single wythe load-bearing walls of a small building with two ADA restrooms and a small storage room for a private park. The building will be ventilated only. My concern is moisture intrusion into the interior spaces. The walls are not insulated.
Will a waterproofing coating at the exterior and the use of a waterproofing additive to the mortar keep water out of the wall system?
Is there an additive that can be added during the mixing and forming of the wall units?
Some think that a single-wythe CMU wall cannot be effectively built to repel moisture. It can. I am attaching a NCMA TEK that can be very helpful. Water repellant is typically put into architectural CMU as a standard procedure especially if the units are colored. You MUST add the repellant to the mortar also. When this is done and you add a compatible flashing at the base of the wall. you should have the wall you are trying to get. If you want to stain or paint the wall I would suggest an elastomeric coating as it will bridge any small voids. You should contact Lisa Pelham (813-255-4737) @ Oldcastle or Daryl Gorenflo (407-280-1487) @ A-1 Block. Either are more than willing to help you, TIf I can also help I'm in Gainesville. Call me. Be safe.
Jerry Painter, FASTM,CGC, SMC
Leave a Reply.
Jerry Painter, FASTM
Don Beers, PE, GC
Find out more about Masonry
Pre-Apprentice Programs by visiting: