# Flashing for Brick Wall



## Darylh (Jan 2, 2006)

No I don't, you are relying to much on the caulking and whats the 1x3 for?
I would take a masonary abrasive wheel or diamond blade and cut a groove in the mortar and have the flashing fit into this groove (1"deep) and slick in some masonary cement.


----------



## gshock (May 30, 2007)

sandyman720 said:


> Do you all think this is leak proof?
> 
> http://public.fotki.com/rdsandy/matts_pics-1/ebay/ebay1/smartvent.html


My first guess would be, "No." You'll want to check with Ed the Roofer, and some other very knowledgeable people on this forum. From my experience, you'll run the risk of getting water build up in the lip of the flashing, and if not sealed 100%, you'll get leaks down the side of the chimney. I believe the correct way to mount the flashing is to bend the top edge to create a lip and insert it into the mortart. You'll need to cut a small horizontal groove in the mortar so that the lip of flashing slides in between the bricks, and then caulk that seam.


----------



## sandyman720 (Mar 6, 2007)

That was my first impression also, but the tech from DCI who makes the smartvent told me to do it like this.


----------



## gshock (May 30, 2007)

sandyman720 said:


> That was my first impression also, but the tech from DCI who makes the smartvent told me to do it like this.


It wouldn't be the first time that a tech has given the wrong information. I'd trust the roofers on this one. I'm not, but this is what I've seen from others.


----------



## Ed the Roofer (Jan 27, 2007)

Although the more commonly suggested method of installing a counter flashing attached to a brick chimney or wall is to cut out the mortar joint, blow out the embedded mortar dust, install a polyurethane sealant into the joint, insert the bent ledge of the top of the sheet metal counter flashing into the joint and then to anchor the counter flashing to the structure or to the masonry surface with either tap-con masonry screws or lead/zinc nail-ins, there is some debate as to whetrher or not that properly makes the structure water-tight.

One suggestion is to place a foam backer rod behind the sheet metal counter flashing just below the ledge to account for expansion and contraction.

I have no idea where the suggestion for inserting a 1" x 3" firring strip or lath board behind the counter flashing came from. That is a new one to me.

If the masonry joint is not cut out properly, the previous method could create more problems than the intended solution it was trying to become.

The most important portion of the sheet metal counter flashing for water tight integrity is the caulking that gets embedded behind the sheet metal prior to attaching it to the structure with the masonry fasteners.

The location of this caulking would be around the top edge of the 1" x 3" in the previous diagram. The open hem or trough MUST be properly sealed with caulking so as not to puddle up any accumulated water.

Many commercial roofing diagrams drawn up by architects do not require the cutting out of the mortar joint and I have installed thousands of feet of counter flashings in both methods, with the only leak one time occurring from a reglet being cut out, which allowed moisture to wick past the flashing components.

Ed


----------

