Putting Down the Paintbrush
A friendly reminder from your friends here at The Pines Preservation Guild that if you’re considering the painted brick trend for your historic house, it may be wise to put the paintbrush down and leave your historic masonry alone.
Historic brick walls (1870-1940-ish) were built so that moisture could escape through soft, porous mortar, not through the brick itself. The mortar is sacrificial and can be easily replaced, while it is more costly and difficult to replace damaged bricks or stone. When brick is painted with something other than a lime wash, moisture is trapped and trapped moisture can quickly deteriorate a wall. As the bricks begin to degrade, the paint will start to peel and flake away, and often spalling will also occur. Spalling is when the face of the brick flakes off, causing a concave appearance, essentially destroying a brick.
In this photo you can see the paint failing and taking the face of the brick with it. This is called spalling and is irreversible.
Just by painting a brick surface, you're turning a virtually maintenance-free material into one that needs regular and often costly maintenance every 3-5 years.
We also want to emphasize to avoid using waterproofing paint like Drylok. It’s almost impossible to remove without damaging the brick. Few if any chemicals work on this type of paint, and when it’s all removed, you’ll likely need to repoint because the only way to remove the waterproofing paint is to go at it from the mortar joints. It also does not allow your historic brick to breath and at a subterranean level, like most basements are, your brick wall is constantly being bombarded with water. The waterproofing paint does not allow this moisture to move completely through the wall, and it becomes trapped.
A basement wall covered in waterproofing paint. The moisture retention is causing both the paint and the brick to fail.
So now you know why not to paint your historic brick. But what if you’ve become a steward of a heritage structure with painted brick? Here are your options:
Remove the paint. Really the only option is a chemical stripper. We like Prosoco's paint remover, but it's a strong chemical, and the process can be painstaking. DO NOT sandblast your brick, ever.
Maintain the existing paint. Use mineral-based or silicate paint that’s designed to be breathable, and is recommended for brick. And with the painstaking prep work needed to repair any damage and ensure a lasting paint job, it's worth working with a professional. And remember you will need to repaint every 3-5 years.
So resist the incredibly strong urge to pick up the paintbrush and instead embrace your structure's natural brick. You and your wallet will be grateful when you don't have to paint every 3 years, future owners will thank you for not causing issues, and your building will thank you for helping keep its structural integrity!
