Brick Veneer Chimney with Standing Seam roof - Need help flashing

[OneSilverTruck]

Hello,

I am a frequent reader, but seldom if ever have posted. I have worked in the general contracting field for 15 years, Owned my own building contracting business for 6 years, and also have a BS in construction management.

Currently we are building a in NW Florida that has two Firerock chimney boxes, with Duravent metal flues. We will build a wood framed chimney that will have a brick veneer. The roof will be a standing seam galvalume.

In all of my years doing this both for commercial and residential, I have not encountered this particular situation before. My training tells me that the best flashing would be to do a thru wall flashing that is adhered vertically to the plywood sheathing behind the brick, and then have a counter flashing that slides underneath. This would be fine on the downhill side. But my concern is how to do this on the rake side.

Roofer tells me to lay the brick, and he will cut a reglet, and simply NP-1 the flashing to the brick. I have done this in re-roof situations and select locations in commercial buildings, but dont really like it.

This house will be the owners primary house/dreamhome for many years to come, not to mention that they are my best friends. I dont want call backs!

I have searched high and low, but cant find any details.

Any help would be appreciated.

Thanks,

[Allan Edwards]

Is the brick on the chimney full size or thin brick? If thin brick, I assume you are doing a scratch coat on the sheathing?

[OneSilverTruck]

We will either do a full size Old Chicago brick or either split them in half(approx 2" thick)..

We looked at doing the scratch coat and thin brick, but have been told by many that the heat will cause them to fall off over time...

[Mark Parlee]

Do you have any drawings you can post?

it's easy to think that we understand what it looks like and where it is going but a drawing would help

[NW Architect]

Thru-wall step flashing with bottom hemmed about 2" above shingle plane - to be the counterflashing. Roofer tucks underlayment slightly under bottom edge of counterflashing, and tucks step flashings fully under counterflashing

[ThingOfBeauty]

Assuming you'll have masonry support under the brick:
--install support masonry 4" above roof on downhill side
--on sides where roof slopes, typically two sides and at cricket on high side(rake sides as you said): install support masonry stepped parallel to roof, closest corner before stepping up between 2" and 4" above roof (same as NW says, but around here we aim higher than 2" especially since code changed to 4" minimum step flash height). Keep steps parallel. We usually step up two bricks on brick veneer, 6" for stone.
--Recently we started adding a flexible through-wall flashing such as Grace Perma-Barrier or Carlisle. Up wall under WRB, across masonry, down to roof plane lapping over roof paper.
--Metal through-flashing across brick, turned up under WRB on chimney chase, across masonry, down about an inch with a hem--just as NW said. Ideally a piece per step with corners soldered, lapping over step below.
--counterflashing piece or pieces, tucked under hemmed through-flashing, that cover roof step flashings.
Pretty much what NW said but added self-adhered through flashing.
This is good both for weathering in quickly, and backup flashing under the metal in case something goes awry.

PS if you don't have masonry support under the veneer, all this would change based on how you're supporting the veneer and how far above the roof plane the support is.