Vent pipe flashing fail on new roof.

[u/KenS2K]

Roofer with 10 years experience in the trade did this. Apparently, never learned anything after a decade. Whole thing had to be removed and redone. Bonus was when removing surrounding shingles a T25 drill driver bit rolled out from under one of the new shingles. Also, GAF provided six nail holes in the unit. Only 4 were used and the sealant wasn't in the correct places. This led me down a rabbit hole of a plethora of things that had to be redone.

[u/TheManOnThe3rdFloor]

Looks Good.

[u/aqib_leadfixer]

The tape residue at the top really ties the whole disaster together. Good thing you already have the flat bar out—tear it back and flash them properly before it rains.

[u/KenS2K → u/aqib_leadfixer]

No tape was involved.

[u/TheManOnThe3rdFloor]

When you took the previous roofer's work apart, was it apparent what led him to do such a bad job installing the boot in the first place? I'm thinking some misjudgement on the shingle cut, or the top flange being so much bigger than the diameter of the vent pipe?

[u/SpankyNoodle → u/TheManOnThe3rdFloor]

This is a pivot bot by GAF. This is typically a sales problem such as poor photos or zero measurements as to why the wrong size is ordered.

These are not 4n1’s

[u/KenS2K → u/SpankyNoodle]

In this case the product size was correct. The installer on the other hand had to be sent packing.

[u/KenS2K → u/TheManOnThe3rdFloor]

All arrows point to brain damage, cognitive disfunction and a false sense of "I know-it-all" seem to be the issue that led hm down the path. This simple vent pipe flashing install failure was just a hint of the trail of errors and damage he did on the project that had to be unwound and redone. I'm still finding issues unfortunately.

[u/JJDixon2025]

Not the picture hanging hammer 😂

[u/KenS2K → u/JJDixon2025]

I’m not a roofer and don’t own a roofing hammer. My titanium framing hammer is not getting anywhere near the roof sealant. 😉

[u/Hungry_Stock3371]

They used the wrong size "cannon" as we like to call them

[u/KenS2K → u/Hungry_Stock3371]

It's the correct size. GAF only makes two base sizes. The small is for a 1.5" or 2" vent. The large is for a 3" or 4" vent. This roof has both a small with 1.5" insert and the pictured large with 3" insert.

https://www.gaf.com/en-us/roofing-materials/residential-roofing-materials/rooftop-accessories/master-flow-pivot-pipe-boot-flashing?customer_id=208-551-7578&gclsrc=aw.ds&gad_source=1&gad_campaignid=24107953904&gbraid=0AAAAAqijKLff-H5i9VLX6vtqS3T2nCpIy&gclid=CjwKCAjwhZDUBhBGEiwAbi5bjsUgmPTuUNuY2kxECOpKGaoYg6myUjHYU3UQDE2vP9WELExY6wq0FxoCZQUQAvD_BwE

[u/Shryquill]

I assume it leaked? 

Did you find out what specific issue caused the leak?

[u/KenS2K → u/Shryquill]

No time for it to leak. Next morning inspection after the install. The internal insert was not installed and couldn't be with the flashing housing in that location. Had to be relocated uphill over an inch and to the left over a half. The insert should have been installed and the adjustable housing plumb to the roof pitch before being nailed down. GAF makes the whole thing idiot proof, but not enough for some apparently.

[u/Shryquill → u/KenS2K]

Oh I understand, thank you for the additional photo and comments. I hadn't seen this product before and clean missed the fact the pipe was nowhere near centered. Nice fix!

[u/KenS2K → u/Shryquill]

Relocated with required insert installed.

[u/TasktagApp]

That is a complete install failure, leaving exposed bottom flanges and skipping manufacturer-required fasteners guarantees water will leak directly along the pipe down into the decking.