fire pathways

[jaggedben]

Yes I didn't regard that pathway as being adjacent. Interpretation is certainly complicated by its crossing over mutliple roof planes, some of which are clearly not adjacent. Also I admit to having a prejudice that the pathway itself should be directly adjacent to the relevant roof plane, or at least not on the opposite side of an array that is on an adjacent plane. But perhaps that is a holdover in my mind from older code language, because I see that with the present wording that's not strictly required.

But in any case a second point is the 'for each roof plane" language. They've got three planes on the upper roof that have solar panels, and therefore need to show three pathways.

 

[jaggedben]

(Also in this case I would draw in the additional pathway straddling that hip because you can. And that can't hurt your chances of getting your permit the first time you submit.)

 

[wwhitney]

But in any case a second point is the 'for each roof plane" language. They've got three planes on the upper roof that have solar panels, and therefore need to show three pathways.

I assume you mean identify pathways for each of the 3 roof planes with photovoltaic arrays--one pathway could satisfy the requirement for multiple planes.

Also, is the north facing roof plane adjacent to the south facing roof plane? I would think so, as they intersect at the ridge. In which case if a 3' x 3' roof access point can be identified on the north eave, then a pathway to the main ridge can be shown on the north facing roof plane.

Cheers, Wayne

 

[jaggedben]

...--one pathway could satisfy the requirement for multiple planes.

I think this is ambiguous in the language and I would not put myself in the position of trying to argue your interpretation to an AHJ ex-post-facto. (Pun intended).

Also, is the north facing roof plane adjacent to the south facing roof plane? I would think so, as they intersect at the ridge. In which case if a 3' x 3' roof access point can be identified on the north eave, then a pathway to the main ridge can be shown on the north facing roof plane.

In this case I would agree.
Now suppose the hip layout comes to a pyramid point instead of a short ridge.

I will add that this discussion is already a good illustration of why clear application of these rules is more an art than a science, if for no other reason that the code could not in any possible world write rules that account for every possible roof layout. I mean, the case in point is a pretty simple layout.

 

[solarken]

What rigid code requirements can't include is the practical considerations for what fire personnel would actually do in an emergency situation. In many cases, t makes more sense to just ask a fire official to meet you at site and review the optimal solar array placement and discuss how they would fight a fire with and without the solar array there. It is generally allowed to defer to local officals to determine pathways.

 

[Zee]

Thanks guys.

Let's go thru the requirements:
1. minimum 2 pathways. check.
2. one from street or driveway . check.
3. For each roof plane with a photovoltaic array, not fewer than one 36-inch-wide (914 mm) pathway from lowest roof edge to ridge shall be provided on the same roof plane as the photovoltaic array, on an adjacent roof plane or straddling the same and adjacent roof planes.

It comes down to what is an "adjacent roof plane".
Based on some official drawings from an AHJ posted by another above , I saw the AHJ interpret "adjacent" as the opposite facing roof, ie, sharing a ridge.
Whereas, I and almost everyone I know, thought "adjacent roof plane" meant sharing a hip or valley.

This could means we could cover a south roof 100% in some cases, which is a shocker.

 

[Zee]

Yeah, I must say that the language "for each roof plane [with PV]....not fewer than 1 pathway" makes it clear to me that there must be 1 pathway per PV roof plane.

 

[wwhitney]

It comes down to what is an "adjacent roof plane".
Based on some official drawings from an AHJ posted by another above , I saw the AHJ interpret "adjacent" as the opposite facing roof, ie, sharing a ridge.
Whereas, I and almost everyone I know, thought "adjacent roof plane" meant sharing a hip or valley.

Adjacent just means next to. There is no implication as to elevation. If two roof surfaces share an edge, they are adjacent. The adjacency could be via a ridge, or a hip, or a valley, or I guess a gutter/eave in a butterfly roof (although that one won't help you get to the specified ridge).

Yeah, I must say that the language "for each roof plane [with PV]....not fewer than 1 pathway" makes it clear to me that there must be 1 pathway per PV roof plane.

Where are you getting that language? CRC R324.6.1 says "For each roof plane with a photovoltaic array, a pathway . . . shall be provided . . ." To me that obviously means that a pathway may serve multiple roof planes. I.e. it just means "if you point to a roof plane with a PV array, I need to point to a pathway that meets the requirements."

Cheers, Wayne

 

[jaggedben]

I think 'adjacent' could be hip, valley, or ridge. But I do think they mean one pathway per plane with panels.

 

[jaggedben]

Aha. Residential code says "for each ... a pathway shall be provided." Fire code says "for each ... not fewer than one pathway shall be provided." So they are not completely the same and I interpret the fire code as being more stringent, requiring a dedicated pathway for each plane. Otherwise what differences does 'not fewer than one'. Or make of it what you will, but I'm still avoiding having this conversation with an AHJ after my mounts are in.

 

[Fred B]

Question from seeing marketing for solar shingles, what effect or compliance issues for pathways or allowance with that product vs standard panels? Would the fact that solar shingles are walkable change the required pathways?

 

[wwhitney]

Aha. Residential code says "for each ... a pathway shall be provided." Fire code says "for each ... not fewer than one pathway shall be provided."

Still not seeing how "shall be provided," or "a" vs "not fewer than one," implies exclusivity. Now if the language were about "dedicated pathways" or "separate pathways" or something like that, I'd agree. But right now I just read it as "in each of these cases, you must be able to get from A to B."

Cheers, Wayne