Using the wrong product on masonry can have long-lasting and expensive consequences

Using the wrong product on masonry can have long-lasting and expensive consequences

Masonry is a porous material and therefore the coatings you apply must be appropriate to the objective you wish to achieve. Oosting Custom Masonry in Midland Park, New Jersey is an expert in masonry construction, preservation, and repair. Whether the masonry is brick, stone, or concrete block, the experts from Oosting caution that all masonry coatings are not alike and using the wrong product may cause irreparable and costly results.

Bricks are permeable

Bricks are used as a common building material for chimneys and other hardscapes because it is both strong and resilient…remember even the big bad wolf from the beloved children’s story The Three Little Pigs, huffed and puffed and couldn’t blow down the brick house. The intrinsic porous nature of brick is both a positive and a negative. The permeable value of brick makes it a great insulator as well as a fire resistant and non-combustible material. That’s why you see chimneys constructed from brick. One of the biggest negative aspects of brick and other masonry products is its penetrable composition which makes it subject to weather damage. The website for the Chimney Safety Institute of America, CSIA, explains it this way, “All masonry chimney construction materials, except stone, will suffer accelerated deterioration as a result of prolonged contact with water. Masonry materials deteriorate quickly when exposed to the freeze/thaw process, in which moisture that has penetrated the materials periodically freezes and expands causing undue stress. Water in the chimney also causes rust in steel and cast iron, weakening or destroying the metal parts.”

Because of the damage water can have on bricks, especially when freezing and thawing, proper care must be taken to preserve the brick as well as prevent water from seeping through the defective masonry and causing damage throughout your home. Therefore coatings are often applied to help in the preservation process.

There are two basic types of masonry coatings: penetrating sealers and non-penetrating. There are also acrylic and polyurethane products which are often used on concrete.


Choosing and applying the proper coating to your masonry is best left to a professional mason. Every home improvement store has a variety of products on their shelves with labels boasting the product’s waterproofing abilities. However, any mason worth his weight in bricks will tell you that you do not want a barrier to moisture. Instead, they will recommend a breathable coating for your outdoor masonry. The last thing you want to do is trap existing moisture in the bricks and have that retained water seep into your home, damage your walls, and weaken the integrity of your structure. Trapping moisture is exactly the opposite of what you want to do when applying a coating to your masonry. Instead you want to preserve the breathability and use the coating to fill in any small gaps and cracks in the masonry and mortar. The proper breathable coating will seep into to the brick and fill in those gaps, while still allowing the capillary effect (drawing moisture in during the night and releasing during the day which regulates the humidity and temperature inside your home) to continue.

It must also be mentioned that in order to be effective, the application of the product is critical as is the prep work before the application. Bottom line…once again, call a professional for an evaluation of the condition of your masonry before you have a problem. If a problem should arise, don’t make matters worse by applying the wrong product. Call a professional like Oosting Custom Masonry & Chimney Service Co to schedule an appointment. We have access to professional grade products and the expertise and equipment to use them properly.