California Spark Arrestor / Chimney Cap

[ColdNorCal]

Have read a lot of sites that state California requires a 5/8" mesh screen on chimney cap to meet code compliance. Most online chimney suppliers mentioned this and sell their 5/8" chimney caps as California compliant. This can be misleading sine local codes follow the California Building Code:

R1003.9.1 Spark arrestors. All chimneys attached to any appliance or fireplace that burns solid fuel shall be equipped with an approved spark arrester. The spark arrestor shall meet all of the following requirements:
1. The net free area of the arrestor shall not be less than four times the net free area of the outlet of the chimney flue it serves.
2. The arrestor screen shall have heat and corrosion resistance equivalent to 12 gage wire, 19-gage galvanized steel or 24-gage stainless steel.
3. Openings shall not permit the passage of spheres having a diameter greater than 1/2 inch (13 mm) nor block the passage of spheres having a diameter less than 3/8 inch (10 mm).
4. The spark arrestor shall be accessible for cleaning and the screen or chimney cap shall be removable to allow for cleaning of the chimney flue

The flex liner kit I installed came with a SS rain cap with 5/8" diamond style mesh. Here are a couple of ideas to make it code compliant however, I am open to other suggestions.

1 - Replace the 5/8" SS mesh with 1/2 galvanized 19 gauge screen available at home depot. Prefer not mixing SS with Galv but its an option.

2 - Thread SS wire 24 awg, or thicker, through the middle of 5/8" diamond shaped holes. This does block a 1/2" sphere and meets the other code requirements.

3 - I emailed a couple of online chimney parts suppliers to see what they offer.

4 - Looked on eBay for ss 1/2" screen and got frustrated...

 

[bholler]

Have read a lot of sites that state California requires a 5/8" mesh screen on chimney cap to meet code compliance. Most online chimney suppliers mentioned this and sell their 5/8" chimney caps as California compliant. This can be misleading sine local codes follow the California Building Code:

R1003.9.1 Spark arrestors. All chimneys attached to any appliance or fireplace that burns solid fuel shall be equipped with an approved spark arrester. The spark arrestor shall meet all of the following requirements:
1. The net free area of the arrestor shall not be less than four times the net free area of the outlet of the chimney flue it serves.
2. The arrestor screen shall have heat and corrosion resistance equivalent to 12 gage wire, 19-gage galvanized steel or 24-gage stainless steel.
3. Openings shall not permit the passage of spheres having a diameter greater than 1/2 inch (13 mm) nor block the passage of spheres having a diameter less than 3/8 inch (10 mm).
4. The spark arrestor shall be accessible for cleaning and the screen or chimney cap shall be removable to allow for cleaning of the chimney flue

The flex liner kit I installed came with a SS rain cap with 5/8" diamond style mesh. Here are a couple of ideas to make it code compliant however, I am open to other suggestions.

1 - Replace the 5/8" SS mesh with 1/2 galvanized 19 gauge screen available at home depot. Prefer not mixing SS with Galv but its an option.

2 - Thread SS wire 24 awg, or thicker, through the middle of 5/8" diamond shaped holes. This does block a 1/2" sphere and meets the other code requirements.

3 - I emailed a couple of online chimney parts suppliers to see what they offer.

4 - Looked on eBay for ss 1/2" screen and got frustrated...

5/8" dismond mesh passes those requirements it wont let a 1/2" sphere through it.

 

[Ludlow]

Clog city.

 

[bholler]

Clog city.

Yeah near us any property on or bordering state or national forest needs spark arrestors. And they are a maintenance issue

 

[Ludlow]

Must it share a border or just a certain proximity?

 

[bholler]

Must it share a border or just a certain proximity?

I beleive it is bordering or a set proximity. So if you border it you need one but you can still need it even if you dont border it but are in close proximity.

 

[ColdNorCal]

Yeah near us any property on or bordering state or national forest needs spark arrestors. And they are a maintenance issue

Given the environment in this area its a risk not worth taking. The sooteater will get tested from the bottom up.

5/8" dismond mesh passes those requirements it wont let a 1/2" sphere through it.

Interesting. I can pass a 1/2" bolt through the middle of the diamond.

 

[bholler]

But i would have to look it up. I dont remember all the regs off the top of my head

 

[bholler]

Given the environment in this area its a risk not worth taking. The sooteater will get tested from the bottom up.



Interesting. I can pass a 1/2" bolt through the middle of the diamond.

Are you sure it is the 5/8" stuff and not 3/4"? The diamond should measure 5/8" on the long side and a little less that 1/2 on short side

 

[ColdNorCal]

Are you sure it is the 5/8" stuff and not 3/4"? The diamond should measure 5/8" on the long side and a little less that 1/2 on short side

The short width is ~5/8". Looking at pics of 5/8" screens, they all look longer then 5/8" on the long side. I emailed the supplier yesterday and may call them later.

https://www.amazon.com/dp/B017088MW2/?tag=hearthamazon-20

(broken link removed to https://www.woodlanddirect.com/California-Cap-5-8-Mesh-Screen)

This one explains the 5/8" width:

https://www.northlineexpress.com/8-x-19-gelco-stainless-steel-chimney-cap-5-8-mesh-13306-1171.html

"Many localities (primarily in California) have spark arrestor codes that call for 1/2" spark arrestors. California code states that a sphere larger than 1/2" in diameter should not penetrate the screen. Thus, the spark arrestor screen actually measure 5/8" from center to center, but still won't let a 1/2" sphere through. This makes them somewhat clog resistant while still..."

 

[Ludlow]

But i would have to look it up. I dont remember all the regs off the top of my head

Where can I find this?

 

[bholler]

Where can I find this?

We have it in the regulations book from dcnr. They may have it on their site.

 

[bholler]

The short width is ~5/8". Looking at pics of 5/8" screens, they all look longer then 5/8" on the long side. I emailed the supplier yesterday and may call them later.

https://www.amazon.com/dp/B017088MW2/?tag=hearthamazon-20

(broken link removed to https://www.woodlanddirect.com/California-Cap-5-8-Mesh-Screen)

This one explains the 5/8" width:

https://www.northlineexpress.com/8-x-19-gelco-stainless-steel-chimney-cap-5-8-mesh-13306-1171.html

"Many localities (primarily in California) have spark arrestor codes that call for 1/2" spark arrestors. California code states that a sphere larger than 1/2" in diameter should not penetrate the screen. Thus, the spark arrestor screen actually measure 5/8" from center to center, but still won't let a 1/2" sphere through. This makes them somewhat clog resistant while still..."

I stand corrected. But i know a 1/2" dia pin doesnt fit through the 5/8" diamond mesh we get from olympia.

 

[ColdNorCal]

I stand corrected. But i know a 1/2" dia pin doesnt fit through the 5/8" diamond mesh we get from olympia.

Thanks for the confirmation. I was confused as to why a 1/2" bolt would fit into the mesh but a sphere would not pass through.

 

[ColdNorCal]

Clog city.

Agreed. Some will clog sooner then others. The more screen surface area the longer it will take to clog.

 

[begreen]

We had a finer 1/2" screen on our class A cap. It never clogged until one year I burned some damp soft maple. Then it clogged within a month and only about 1/2 cord burned.

 

[ColdNorCal]

We had a finer 1/2" screen on our class A cap. It never clogged until one year I burned some damp soft maple. Then it clogged within a month and only about 1/2 cord burned.

Was your screen this style?

https://www.homedepot.com/p/Everbil...nized-Steel-Hardware-Cloth-308221EB/205960835

Im considering wrapping the screen on the outside of the cap supports which will provide a little more screen surface area then placing the screen on the inside. This is the style of cap.

https://www.houzz.com/product/25889...flex-square-3-traditional-heating-and-cooling

 

[begreen]

Was your screen this style?

No, ours is 1/2" square stainless mesh. I would not use galvanized for this screening. High heat & condensation there will ensure a short life for a galvanized screen. Check local hardware stores to see if they have this on bulk roll so you only buy what you need and not a full roll.
or order online?
https://www.twpinc.com/wire-mesh-material/welded-stainless-mesh/welded-wire-mesh-type-304

 

[ColdNorCal]

No, ours is 1/2" square stainless mesh. I would not use galvanized for this screening. High heat & condensation there will ensure a short life for a galvanized screen. Check local hardware stores to see if they have this on bulk roll so you only buy what you need and not a full roll.
or order online?
https://www.twpinc.com/wire-mesh-material/welded-stainless-mesh/welded-wire-mesh-type-304

Understood although it does meet California code.

I appreciate the link but its a little pricey for a one off :

"The minimum order for welded stainless steel mesh is $100 per item. "

 

[Hogwildz]

1/2" Screens don't clog, unless you burn wet wood, or at real low smoulder temps.
I replaced my screen that rotted away after 10 years, with 1/2" galvanized. No issues so far, and it is cheap enough to replace as needed.

 

[bholler]

1/2" Screens don't clog, unless you burn wet wood, or at real low smoulder temps.
I replaced my screen that rotted away after 10 years, with 1/2" galvanized. No issues so far, and it is cheap enough to replace as needed.

Many people have issues with even 3/4" diamond clogging even with good wood and burning techniques. There are lots of variables

 

[ColdNorCal]

1/2" Screens don't clog, unless you burn wet wood, or at real low smoulder temps.
I replaced my screen that rotted away after 10 years, with 1/2" galvanized. No issues so far, and it is cheap enough to replace as needed.

That $7 roll from HD is enough to make a 6"x24" screen 10 times. Was your original screen SS? Did you replace it with galv this past winter?

fwiw - the burn season here is shorter then most areas and we usually spend 6-8weeks during the winter visiting family in Thailand.

 

[Hogwildz]

That $7 roll from HD is enough to make a 6"x24" screen 10 times. Was your original screen SS? Did you replace it with galv this past winter?

fwiw - the burn season here is shorter then most areas and we usually spend 6-8weeks during the winter visiting family in Thailand.

I think the original was s.s. It was mostly the end strands that rotted away. Got tired of messing with them, and getting poked by them. The galv has been in for at least 2 years, is a lil thicker, and was repurposed from stuff lying around. Cost = $0.00

 

[ColdNorCal]

A vendor is supplying the 5/8" SS screen and is very fair about it.

Depending on the actual screen dimensions, I will try to make the screen surface area larger to compensate for the smaller 5/8" size. Mounting the screen on the outside of the rain cap legs will add something. Wont know how much until the screen is here.

This is the style of cap:

https://www.amazon.com/dp/B00RM09GWE/?tag=hearthamazon-20