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Screened porch

Sifu

SAWHORSE
Joined
Sep 3, 2011
Messages
2,809
Recently had a question put forth about allowing a direct vent f/p to terminate on a screened porch. Opinion was given that the porch is enclosed therefore not permitted. I don't see screening as enclosing. The mfr specs give clearances for installation on porches under roofs but qualify them by saying that the porches must be completely open on two sides. How do you folks feel about screening as enclosing?
 
It seems the application in question may not fit into the manufacturers installation requirements depending upon how the porch is screened off. Not that I feel the screen is the issue rather the application I typically see for screened porches is half walls with openings above that are screened. Completely open is just that, completely open. I have people argue similar instances for carport/garage applications where they want a fence enclosing the sides of the carport, not really open.

ZIG
 
ditto to sigmark. the manufacturers instructions are the ruling deal here, , if it doesn't meet the definition, it doesn't meet the definition. id say it's enclosed. it's enclosed by screening and whatever is supporting that screening, and a roof most likely, no
 
What would be the safety issue? We have thousands of screen porches with fireplace vents on them. The screen will not significantly restrict the airflow. This is a non issue IMO unless I have misread your post. Brudgers?
 
I'd lean towards not open, airflow will be restricted somewhat, so it is not open.....

JMHO
 
There used to be a patio cover that earned an ICBO ESR# as an open patio cover. It had windows that could be blocked by glassine or bug screens as long as the glassine (plastic) and screens can be removed without the use of tools. Now that's an "open patio cover" per ICBO definition that could get you killed per the definition of "dead".
 
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Why does it need to be open?

To prevent the accumulation of combustion gasses.

Assuming that a "screened porch" is mostly comprised of screened walls, there's no way that gasses will accumulate.

Diffusion will assure that even in the absence of air movement.
 
My contention would be screening is open. In other words as Brudgers and Daddy-O put it, there could be no accumulation of gases since they could dissipate. As long as the clearances are met from the obstructions per the specs what hazard would exist? I had not considered the 1/2 wall aspect which would be considered as not completely open by definition. Then again a covered porch without screen or open deck could have 1/2 walls or guards and not meet that definition either.
 
How tight is the mesh on the screen? Some mesh is so tight that the most minute amounts of dust, spider webs and the like willl almost completely shut of air movement.
 
M contention would be that if screened it should be considered not open."Confined"

The screening used on porches for bug control will accumulate dust dirt and pollen and has the potential to clog and prevent air movement. This same scenario using snow and sleet and condensation from the flue gas can compound the issue quickly.

Now considering that less than 3% of all fossil fuel equipment is not set up with a combustion analyzer this further increases the chance of carbon monoxide poisoning.
 
While not really my cup o' tea, I have two bits to throw in.

Around here there are several saloons (and a few homes, no idea how many) that have a screened porch for al fresco beverage consumption, dining, card playing... idle time. Most of these are convertible... that is to say, when the weather turns there are glazed sashes that are installed in lieu of the screens. Thus the space is usable for more of the year.
 
Doorman said:
While not really my cup o' tea, I have two bits to throw in. Around here there are several saloons (and a few homes, no idea how many) that have a screened porch for al fresco beverage consumption, dining, card playing... idle time. Most of these are convertible... that is to say, when the weather turns there are glazed sashes that are installed in lieu of the screens. Thus the space is usable for more of the year.
My two cents: The law requires you to inspect what's there at the time of inspection

Not what you fantasize about at night.
 
The law requires you to inspect what's there at the time of inspection, Not what you fantasize about at night.
I would agree with that, that's all you can do. People don't lie to you guys, do they?
 
Gregg Harris said:
M contention would be that if screened it should be considered not open."Confined" The screening used on porches for bug control will accumulate dust dirt and pollen and has the potential to clog and prevent air movement. This same scenario using snow and sleet and condensation from the flue gas can compound the issue quickly. Now considering that less than 3% of all fossil fuel equipment is not set up with a combustion analyzer this further increases the chance of carbon monoxide poisoning.
If the screen is that clogged, there are going to be bigger problems with the house.
 
Doorman said:
I would agree with that, that's all you can do. People don't lie to you guys, do they?
When I worked behind the counter, I was a plans examiner. Not Perry Mason.

And they didn't let me wire people up to a lie detector.

Or water board them.

Or hook a battery up to their naughty bits.
 
brudgers said:
When I worked behind the counter, I was a plans examiner. Not Perry Mason.

And they didn't let me wire people up to a lie detector.

Or water board them.

Or hook a battery up to their naughty bits.
You sure missed out on a lot of fun :D

Agree it is open
 
Add the area of the (2) smallest sides if open. Is the total net free area of the screening equal or greater than the total area of the (2) smallest sides. If so you have equivalent open area.
 
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