Clearance over flat roof ISOLATED

Status
Not open for further replies.
M

MIDBLU

Member
WE have a service upgrade on a house with a large porch and the porch continues to become a carport

See drawing on word doc below.... The house is single story with NO ACCESS to the flat roof area unless
you bring a ladder. It is my position that because the flat roof is "isolated" the clearance from the lowest
part of the drip loops above the highest part of the flat roof it crosses only needs to be 3' not 8' or 10


untitled3.jpg
 
How is the point of attachment above the flat roof, is there a mast? And why change to SER cable?
 
MIDBLU said:
WE have a service upgrade on a house with a large porch and the porch continues to become a carport

See drawing on word doc below.... The house is single story with NO ACCESS to the flat roof area unless
you bring a ladder. It is my position that because the flat roof is "isolated" the clearance from the lowest
part of the drip loops above the highest part of the flat roof it crosses only needs to be 3' not 8' or 10


View attachment 20187
Click to expand...


Presently the point of attachment (shown on drawing) is on the fascia and then run back to the service in
100 A SE cable (along the fascia to a mast). One faction here, says to do the same thing but with 200A SE.

But i was taught not to run more than 10' of SE cable -- at which point it had to hit an OCPD, and change
to SER-- so i fell into the other faction....,

The other faction says to extend the mast head to have the service lateral maintain a clearance above the
flat roof of (? how many feet) 8' was the rule unless it is isolated (inaccessible ?) in which case it is only 3'

There being no doors or windows (single story) opening to make the area accessible i am in a sub group
that say 3' is adequate.
 
If the drop is currently attached directly to the structure I would leave that and just change the 100 amp SE cable to 200 amp SE cable. You can run SEU for an unlimited distance on the outside of the structure.
 
MIDBLU said:
Presently the point of attachment (shown on drawing) is on the fascia and then run back to the service in
100 A SE cable (along the fascia to a mast). One faction here, says to do the same thing but with 200A SE.

But i was taught not to run more than 10' of SE cable -- at which point it had to hit an OCPD, and change
to SER-- so i fell into the other faction....,

The other faction says to extend the mast head to have the service lateral maintain a clearance above the
flat roof of (? how many feet) 8' was the rule unless it is isolated (inaccessible ?) in which case it is only 3'

There being no doors or windows (single story) opening to make the area accessible i am in a sub group
that say 3' is adequate.
Click to expand...
Where are you over the roof? If you did cross the roof you would definitely have to be 8'. 230.24(A). The clearance can be less only near the edge of the roof extending in a max of 3'. Think of a roofer trying to work on the roof with the cable at his waist.
 
MIDBLU said:
WE have a service upgrade on a house with a large porch and the porch continues to become a carport

See drawing on word doc below.... The house is single story with NO ACCESS to the flat roof area unless
you bring a ladder. It is my position that because the flat roof is "isolated" the clearance from the lowest
part of the drip loops above the highest part of the flat roof it crosses only needs to be 3' not 8' or 10


View attachment 20187
Click to expand...

I agree with you, at least in principle. Not quite sure what your getting at with 'isolated' (is that word in the code?) But the clearance requirement above a roof is less than that above a walking surface
 
jaggedben said:
I agree with you, at least in principle. Not quite sure what your getting at with 'isolated' (is that word in the code?) But the clearance requirement above a roof is less than that above a walking surface
Click to expand...

Would a flat roof be considered a "walking surface"?
 
MIDBLU said:
Presently the point of attachment (shown on drawing) is on the fascia and then run back to the service in
100 A SE cable (along the fascia to a mast). One faction here, says to do the same thing but with 200A SE.

But i was taught not to run more than 10' of SE cable -- at which point it had to hit an OCPD, and change
to SER-- so i fell into the other faction....,

The other faction says to extend the mast head to have the service lateral maintain a clearance above the
flat roof of (? how many feet) 8' was the rule unless it is isolated (inaccessible ?) in which case it is only 3'

There being no doors or windows (single story) opening to make the area accessible i am in a sub group
that say 3' is adequate.
Click to expand...

Is there any compelling reason to change the point of attachment to a mast from what you already have installed now?
 
This old thread. Surprised it can still be posted to.

Guys, the walkability of the roof has nothing to do with the main question. Unless the roof is 'readily accessible' and/or 'subject to pedestrian or vehicular traffic', then the roof rules (230.24(A)) apply and not the rules for other situations. (230.24(B)).
 
cowboyjwc said:
4 in 12 is considered a walkable surface
Click to expand...

Actually, for what's relevant to this thread, a lower clearance is allowed for 4 in 12 'or greater'. :happyyes: In other words, at 4 in 12 they don't expect anyone to be walking on it. Or at least so I gather. At 4 in 11.9 it's walkable. :lol:
 
jaggedben said:
Actually, for what's relevant to this thread, a lower clearance is allowed for 4 in 12 'or greater'. :happyyes: In other words, at 4 in 12 they don't expect anyone to be walking on it. Or at least so I gather. At 4 in 11.9 it's walkable. :lol:
Click to expand...

Yes, no mentioning of ease of access or anything like that, just lower clearance allowed for 4/12 and greater. One has to assume they figure nobody is regularly occupying that sort of pitched surface. Probably even figuring that most are not going to be walking around too freely either unless under that pitch. Most roof finishes for those higher pitches aren't designed for regular traffic. Roof finishes for lesser pitches are usually designed to take more abuse (and or traffic), the lower pitch often means more activity can happen on the surface whether intended or not. Things that end up there (for any reason) tend to stay there easier than for a higher pitch.

A
 
Status
Not open for further replies.
Top