For waterproofing cinder block walls, choose a masonry coating that matches the wall’s moisture condition and the pressure it may face. KILZ is a versatile option for interior or exterior masonry, YKF lists resistance up to 15 PSI, and Zinsser is designed for damp walls and lists resistance up to 34 PSI. Ames is a better fit for larger projects or surfaces with small cracks, while INSL-X offers a water-based coating for vertical masonry.
| Product | Best For | Notable Feature |
|---|---|---|
| KILZ Basement and Masonry Waterproofing Paint | General interior and exterior masonry | Lists protection up to 12 PSI |
| YKF Masonry Pro | Below-grade masonry walls | Lists resistance up to 15 PSI |
| Ames Block & Wall Liquid Rubber | Large areas and small cracks | Five-gallon size; fills cracks up to ⅛ inch |
| INSL-X WaterBlock | Vertical concrete and masonry walls | Water-based, alkali resistant up to pH 13 |
| Zinsser WaterTite | Damp walls and higher listed pressure | Lists resistance up to 34 PSI |
KILZ Basement And Masonry Waterproofing Paint
Best for: Homeowners seeking one coating for interior or exterior cinder block, concrete, brick, or other listed masonry. KILZ states that its nanotechnology-based coating blocks up to 12 PSI of water pressure and resists alkali buildup.
The product is also listed for basement walls, stucco, and retaining walls. That range makes it a flexible choice when the project includes more than one masonry surface. For below-grade use, the manufacturer says to fill holes and cracks with hydraulic cement before painting.
Limitation: It is not intended for floors or walls with active water leaks. Do not treat paint as a substitute for resolving active water entry.
YKF Masonry Pro Foundation And Basement Sealer
Best for: Buyers focused on foundation, basement, crawl-space, or retaining walls who want a coating with a stated hydrostatic pressure rating. YKF says Masonry Pro resists pressure up to 15 PSI when applied as directed to properly prepared masonry.
Its water-based polyurethane, high-solids formula is designed to bond to properly prepared dry or slightly damp concrete and masonry. The smooth white finish is also described as helping conceal minor surface imperfections, making it a practical option for refreshing stained walls.
Limitation: The listed pressure resistance depends on proper surface preparation and application. It is a one-gallon product, so check the coverage information on the product label to determine how much the project needs.
Ames Block & Wall Liquid Rubber Waterproofer
Best for: Larger waterproofing jobs or projects where a coating that can bridge small cracks is useful. This five-gallon liquid rubber product is listed for concrete walls and cinder block, as well as ICF, metal, wood, and other surfaces.
Ames says the coating fills cracks and crevices up to ⅛ inch and has up to 1800% elongation. It can be applied by sprayer, roller, or brush, and is described as thick and low odor. Those application options can help buyers choose a method suited to the wall and work area.
Limitation: Its stated crack-filling range is limited to cracks up to ⅛ inch. Larger or active cracks may require separate repair before coating.
INSL-X WaterBlock Acrylic Masonry Waterproofer
Best for: People who want a water-based coating for vertical concrete and masonry surfaces. INSL-X lists basement walls, foundations, retaining walls, cinder blocks, stucco, and brick among its uses, with interior and exterior applications.
The coating is described as fast drying and highly alkali resistant up to pH 13. That alkali-resistance specification can be relevant when choosing a product for concrete or masonry, which can be alkaline. Its one-gallon size suits buyers comparing smaller project quantities.
Limitation: The supplied product details do not specify a hydrostatic pressure rating. If pressure resistance is a key selection factor, compare products with a stated rating and follow each label’s application requirements.
Zinsser WaterTite White Damp Wall Primer
Best for: Buyers dealing with damp masonry who want a product specifically described for application to damp walls. Zinsser lists interior and exterior concrete, masonry, and cast-in-place surfaces, including basements, cellars, and garages.
The product features Portland cement and is designed to help resist seepage and dampness. Its listed hydrostatic pressure resistance is up to 34 PSI, the highest stated rating among the products in this comparison. This makes it worth considering when the pressure specification is a major decision point.
Limitation: The product is identified as a primer, so review its label for surface preparation, application directions, and whether a separate finish coat is needed for the intended project.
Buying Guide: How To Choose A Cinder Block Waterproofing Product
Is the wall damp, or does it have an active leak?
Identify the moisture condition before choosing a coating. Zinsser is specifically described for damp-wall application. KILZ says it is not for walls with active water leaks, and its below-grade instructions call for filling holes and cracks with hydraulic cement before painting. Follow the chosen product’s label rather than applying a coating over unresolved water entry.
Should you compare pressure ratings?
When hydrostatic pressure resistance matters, compare the product’s stated rating and its conditions. The listed figures are up to 12 PSI for KILZ, up to 15 PSI for YKF, and up to 34 PSI for Zinsser. INSL-X and Ames do not provide a PSI rating in the supplied details. Ratings should not be treated as a guarantee for every wall or application.
What surface and application method do you need?
Confirm that the coating is listed for the wall material and location. The products cover different combinations of cinder block, concrete, brick, stucco, retaining walls, and other surfaces. Ames lists brush, roller, and sprayer application. For all options, prepare the masonry as directed and check label instructions for drying, coverage, and coats.
How much product should you buy?
Compare container size with the area to be covered, but use the manufacturer’s stated coverage rather than estimating from the container alone. The listed sizes include one-gallon options and a five-gallon Ames container. Porous, uneven, or repaired masonry may affect how much coating the job requires.
Frequently Asked Questions
Can you paint cinder block walls to help waterproof them?
Yes. These products are listed for cinder block or masonry waterproofing, but they work as coatings and require proper surface preparation. They are not a substitute for repairing active leaks.
Which option is listed for application to damp walls?
Zinsser WaterTite is described as a damp-wall primer for concrete and masonry. Follow its label for application conditions and preparation.
Which product has the highest stated PSI rating?
Zinsser lists resistance up to 34 PSI. YKF lists up to 15 PSI, and KILZ lists up to 12 PSI. Apply each product as directed; ratings depend on product conditions and preparation.
Can these coatings cover cracks?
Ames says it fills cracks and crevices up to ⅛ inch. KILZ recommends filling holes and cracks with hydraulic cement for below-grade application. Repair cracks according to the selected product’s instructions.
Can waterproofing paint be used on floors?
KILZ states that its waterproofing paint is not for floors. Check the label for any other product before using it on a horizontal surface.