How To Make Brick Chimney Waterproof? [Step by Step]
Most of the chimneys are made of brick. It’s been the preferred option for ages. Brick is strong but porous. So, the water seeps in and ruins it. However, when a brick is baked, a waterproof layer is put on top of it.
However, this layer is prone to breaking or losing its strength over time due to the constant sunlight, rain, and weather.
Also, there might be a leak in the chimney’s flashing. So, it becomes imperative to waterproof the brick chimney to preserve its utility and increase its lifespan.
So, here in this article, I’ll share simple methods to waterproof your brick chimney. Let’s start!
Do Brick Chimneys Need to Be Sealed?
Yes, Brick chimneys need to be sealed. Most chimneys are made of bricks, especially in the US. The brick chimneys have bricks (of course), mortar and fire-resistant metal fitted towards the insides.
As mentioned above, bricks are extremely porous. Over the years, it soaks water from rainfall and snowfall. This moisture stays there until it gets evaporated by heat. This process is similar to weathering, which leads to the bricks breaking, hence, weakening your chimney.
Thus, it is extremely necessary to waterproof the bricks and seal them against the forces of nature.
How To Waterproof Brick Chimney Using Sealant Spray?
You’ll find a number of sealant sprays for brick chimneys. Here are a few options for you to check out:
Usually, these sealers are water and siloxane-based. Being water-based, it dries up quickly. Siloxane is a manmade product, usually called silicon. Silicon is widely known as an ingredient in most waterproofing products.
It also has a high heat resistance which makes silicon-based products best suitable for chimney purposes that suffer from heat regularly. These sealant sprays form a layer over the brick preventing the brick from UV radiations, moisture and wind alike.
While applying the sealant spray, pay special attention to the mortar joints, chimney’s crown and flashing.
These regions are the most susceptible and vulnerable to moisture. Also, it’s suggested to apply at least two layers to be sure of the waterproofing nature.
You’ll also require a pump sprayer to spray the sealant over the chimney bricks.
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It makes the process easy. You’d like to start from the bottom part. These are liquids and might trickle down. So, while the sealant runs down, the bottom part will be waterproofed a bit more. So, that’s a win-win situation, right?
Also, please ensure your safety while doing all of these. Have a harness and rope available for use.
Required Material:
- Brick sealant
- Pump sprayer
- Harness
- Rope
- Dishwashing liquid and water
Procedure [Step by Step]:
1. Clean the chimney
Clean the outer surface of the chimney using a solution of soap and water. You can also use a brush to clean the tough stains. This step would provide a smooth and clean surface for sealer application.
2. Apply the sealer
Next, transfer the sealer from the product pack to the pump sprayer.
Spray the sealer over the bricks. Be sure to apply the sealer at least twice within a span of five minutes to ensure the best waterproofing.
The silicon would dry in a 1-2 hours maximum. However, you should allow it to dry for at least a day before it actually starts executing its waterproofing nature.
Precautions:
- As I stated before, please ensure that you’re safe and use a harness and rope to handle yourself.
- Also, do this process in a fairly dry day. You don’t want rain to wash away everything within a few minutes before the sealant actually dries.
Total time required:
The total process (including the 24 hours wait time at the end) would take around 2 days.
Total Cost:
The total cost considering you have dishwashing liquid, harness and rope already available will be (considering approximate values) around $85. Below is the approximate split:
For the sealant: $ 70
For the pump sprayer: $ 15
A total of $ 85
How To Waterproof Brick Chimney Using Silicone Caulk?
The brick chimneys have flashings. When these flashings develop some leaks or cracks, it creates a problem as water starts leaking from those spaces.
To deal with this, one can apply the silicone caulk. Silicone is durable, forms a strong adhesive bond with the surface.
Silicone is also widely used as a waterproofing agent for items under constant or almost regular moisture contact. Silicone can also tolerate heat efficiently. Hence, it’ll be the perfect candidate for use on a chimney.
Silicon waterproofing can help you keep the thing sealed for at least 10 years. So get a good silicone caulk and you’ll relieve yourself from the constant stress.
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Required Material:
Procedure [Step by Step]:
Apply it
Yes, pretty much that’s it. Get the caulk and apply it over areas that seemingly have a leak or crack. The silicone would dry up in a maximum of 3 hours. After which your silicone caulk would protect your chimney and the flashing perfectly.
Total time required:
It’ll take a maximum of six hours to be complete the process.
Total cost:
The only thing you require here is the silicone caulk which would cost around $15.
Final Words:
The first method will be used to seal the entire chimney and the second method would be used to seal off specific portions in the brick chimney like the flashing. When the chimney starts leaking, it’s a sign that moisture has got its way through the bricks or the through some crack.
Alternatively, you can also get professional services from businesses serving chimneys and their waterproofing at a decent cost. Whatever be your preferred choice, taking care of your brick chimney definitely goes a long way. I hope this helped you. All the best!
