The text says 2012 IRC allows continuous flashing? I do not have a 2012 book. Can someone confirm this? Thanks
****R905.2.8.3 Sidewall flashing. ** **
Base flashing against a vertical sidewall shall be continuous or step flashing and shall be a minimum of 4 inches (102 mm) in height and 4 inches (102 mm) in width and shall direct water away from the vertical sidewall onto the roof and/or into the gutter. Where siding is provided on the vertical sidewall, the vertical leg of the flashing shall be continuous under the siding. Where anchored masonry veneer is provided on the vertical sidewall, the base flashing shall be provided in accordance with this section and counterflashing shall be provided in accordance with Section R703.7.2.2. Where exterior plaster or adhered masonry veneer is provided on the vertical sidewall, the base flashing shall be provided in accordance with this section and Section R703.6.3.
This is code and not really relevant. Per manufacturer, asphalt shingles should have step flashing. The size may vary by manufacturer and code in use in various jurisdictions. I’m happy just to find step flashing. I wouldn’t call any step flashing a defect unless it were installed improperly or in a manner that would allow water to penetrate the roof. I always call continuous flashing a defect, but comment on whether I see signs of leakage. On older roofs, with no signs of leakage, I say it’s wrong but I don’t recommend replacement, just say that it’s not right.On new roofs, I explain that it’s wrong and may leak.
The 2009 version allows step-flashing only in R905.2.8.3.
Yep. the manuf. trumps the code. Call GAF/Elk and they will tell you to use step flashing. They are only the largest shingle manuf. in the US. That’s what I tell ever builder & my buyer’s around here. Most still use continuous flashing though cause it’s “allowed by code”.
I feel compelled to play the Devils advocate here. How much sense does it make to state that the manufacturer trumps code when it seems we are referring to a shingle manufacturer. Unless the shingle manufacturer also makes the flashing, the statement does not hold water. (pun intended)
The code allows an exception for continuous flashing for a reason it seems. Unless it can be shown that the flashing manufacturer calls for step flashing in exterior vertical wall applications, I’ll feel safe passing over continuous flashing as allowed by code.
There is allot to that links statement.
Sidewall vertical wall flashing can be apron or step.
True and dependent upon many factors.
Pitch being the most prominent if the run is clear and without valley, dormer. like intrusions close to the vertical side wall.
The decks makeup ply or planking also plays a part.
A plan ply roof.
No obstructions.
Good insulation and ventilation must be in place.
Then it works with apron 4" apron flashing.
Recommend NEVER!
JMO.
