Workshop
Ask a question

The Bunnings Workshop community can help with your home improvement projects.

How to waterproof my outdoor fireplace chimney?

niesie
Finding My Feet

How to waterproof my outdoor fireplace chimney?

17456357612292142650846373219453.jpg

 Hi team, I'm looking for advice on waterproofing this space.  I have no idea, some flashing I guess? I will also be replacing 2 of the clear sheets with metal sheets around the chimney. Appreciated, thanks 😊 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to waterproof my outdoor fireplace chimney chimney

Welcome to the Bunnings Workshop community @niesie. It's brilliant to have you join us, and many thanks for your question about installing a fireplace.

Even though it's an outdoor fireplace, because it's passing through a roofed structure that’s likely attached to your home, you'll need to make sure it complies with local building codes and is professionally installed. That includes having the right type of flashing around the chimney to ensure both waterproofing and fire safety.

 

The correct flashing system will depend on how hot the chimney gets. Some self-adhesive flashings, like those with a bitumen backing, may not be suitable if the flue reaches high temperatures, so a professional installer will need to determine what's safe to use. They'll also need to consider how water will flow down the high side of the corrugated sheeting and meet the chimney—flashing will stop water from falling between the chimney and roof sheets, but if not shaped and installed correctly, it can trap water in the corrugations and lead to leaks or pooling.

 

Because of these technical and safety challenges, I'd strongly recommend engaging a fireplace installation expert. They'll be familiar with the regulations and will know how to handle the custom flashing work needed to make sure the install is safe, durable and compliant. Let me know if you’d like help finding someone to assist or advice on what to ask when getting quotes.

Please let me know if you have any questions.

Mitchell
 

See something interesting? Give it the thumbs up!

Re: How to waterproof my outdoor fireplace chimney chimney

Thank you Mitchell 😊 agreed I may need to consider the pro's for this one. Can you advise on questions for quoting please? Thanks heaps, Reneze 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to waterproof my outdoor fireplace chimney chimney

Hi @niesie,

 

First, inquire about the materials that will be used for the flashing. It’s important to ensure they use something durable, like stainless steel or a weather-resistant bitumen-based flashing, especially given the exposure to the elements and the potential heat around the chimney. Additionally, ask how the flashing will be attached to both the chimney and the roof. A secure attachment is key to preventing leaks, so it’s worth clarifying whether any sealants or adhesives will be used. Lastly, you should ask how the flashing will interact with the water runoff that travels down the corrugated sheeting on the high side of the roof. The flashing should be designed to guide water away from the chimney without allowing it to collect in the corrugations, as this could cause leaks or pooling. 

 

Mitchell

 

See something interesting? Give it the thumbs up!

Re: How to waterproof my outdoor fireplace chimney chimney

Appreciated thanks Mitchell

Why join the Bunnings Workshop community?

Workshop is a friendly place to learn, get ideas and find inspiration for your home improvement projects