Protecting Your Chimney from Air and Water

Protecting your Chimney: With colder weather just around the corner, it is important to be sure that your chimney is in working order. A fault that can cause various issues with your fireplace is cracks or inconsistencies on your chimney stack or the crown on top. Air and water can then find its way inside your chimney and compromise fuel efficiency or even damage the chimney over time. The best way to Protecting your Chimney is to seal the chimney with a weatherproofing compound. There are many brands and types of products for this application, but we will be covering three products that we supply here at Landis Block: CrownCoat, Planiseal88, and MasterProtect EL 750.

CrownCoat is an elastomeric coating that is designed specifically for, well, coating your chimney crown. Being an elastomeric product means that it is a synthetic, rubber-like material that exhibits both viscosity and elasticity. What this means is that it is a flexible material even when fully set and can penetrate into cracks, fully weatherproofing the chimney crown. CrownCoat is also fairly easy to install and includes a 15-year limited warranty if installed by a professional contractor.

A product similar to Crowncoat is Mapei’s Planiseal88. Planiseal88 is a cement-based water-proofing that provides superior protection against water and the freeze/thaw cycle of winter. As a cement based product it can be used in a variety of applications including concrete, brick, and stucco, but is not as flexible as an elastomeric product. Planiseal88 does have the advantage of being polymer-modified which allows it to be used horizontally, vertically, or even on overhead applications which can go beyond chimney protection.

BASF’s MasterProtect EL 750, a.k.a. Thorolastic, is a water based, elastomeric acrylic coating. It is most commonly used on vertical surfaces such as exterior walls or around the stack of a chimney. It has the unique property of functioning like a thick paint; it goes on to the surface as a liquid and as it dries, it attaches itself to the surface underneath, sealing the wall from the outside weather, and being an elastomeric, it is flexible and can persist through any climate. Thorolastic also comes in a wide variety of colors and texture finishes, which are all pre-mixed and ready for use when purchased to give your wall or chimney a weatherproof, stucco-like finish.

Any of these products are a key component in Protecting your Chimney functioning properly so you can enjoy a cozy fire during the winter. Stop in and visit us to see which product would be best for your specific situation.