This concept is foreign to most roofers because I rarely see it. I’m on thousands of roofs and see it maybe 2-3% of the time. Some shingle manufacturers such as CertainTeed and Malarkey require it. ‘Require’ means you’re supposed to do it. Double sealing means apply sealant to both the top of shingles or shakes and the underside of flanges of attic vents ridge vents stem vents pipe jacks AND putting sealant between the tops of these flanges and the underside of the lapping shingles or shakes( if this is giving anyone a headache or if your spurs are starting to spin then take a breather ). Now, it’s going to get real technical here - You get a 5 gallon pail of gun grade, get a high quality Albion caulk gun not a $3.99 Home Depot special, unscrew the cap, spray WD-40 on the threads, put the end of the gun just past the threads in the mastic, draw back the handle and fill the gun, wipe the threads off with old newspapers, use this for places where the sealant is hidden ( not visible ), use colored caulk where it is visible ( not hidden ). Water can and will wick upwards. Water can will go sideways. Sealant will stop this especially in high wind areas. This would be a good selling point for your estimators. Separate yourself from the pack. Offer what 97% don’t do. Trust me it works.
I’m surprised you’ve not been tossed off a roof. Maybe it’s because everyone was too dumb to do it correctly?
Leaking roof - looking for advice, - Roofing/Construction Questions - TalkRoofing.comGod gave you 2 eyes and 2 ears and only one mouth, if you look and listen twice as much as you flap your jibs, you’ll be within specs…
Yes, i call it step-bulling it.
Another word for tar.
Instead of step-flashing it,
You are step tarring it.
I find it a must on chimneys and skylights.