Brick Veneer Flashing

[ncoulson]

Brick Veneer Flashing

I am a Code Inspector and am concerned about a typical treatment of thruwall flashing in the South East on wood frame residential construction.

The typical location of the flashing appears to leave the bottom of the sheathing and the bottom plate exposed to moisture build up and rot.

The flashing is typically taken to the inside face of the stud wall. As a result it leaves a potential gap at the bottom of the housewrap, where any moisture flowing down the housewrap can wick in

This could be prevented if the flashing were taken up under the housewrap against the front face of the sheathing, lapping it by at least 6”.

A brick veneer wall is already vulnerable to moisture intrusion, and the bottom of the cavity is typically full of mortar droppings impeding drainage. Additionally the use of 6 mil poly for flashing is, of course, cause for concern, but code does not disapprove this.

To compound the problem, the nailing of sheathing to the bottom plate is critical in high wind areas to securing the building for shear and uplift. If this sheathing stays wet, the nails loose their strength, and eventually moisture migrates inside.

Does anyone know any reasons why the flashing is taken to the inside face of the studwork?

Does anyone see problems with requiring it be brought to the face and lapped with houserap ?

[Top Notch]

I would rather see that flashing at the face of the wall under the WRB myself. Perhaps that isnt polyethylene but was meant to be flashing tape. Im no mason either but I believe pea gravel is supposed to fill the cavity base to allow drainage in case of mortar build up. They also make a felt.

[Mark Parlee]

Here is a great guide to some of the details
http://www.olympiancares.com/mason%2...k%20veneer.pdf

[tom struble]

thanks Mark,not a mason but nice to get a heads up on the masonry to siding transitions

[Mark Parlee]

Tom
It is a well written document; amazing how many do not follow anything close.

[ncoulson]

Appreciate people's input. My questions remain:

Does anyone know any reasons why the flashing is taken to the inside face of the studwork?

Does anyone see problems with requiring it be brought to the face of the sheathing and lapped with housewrap ?

Nick Coulson

[tom struble]

seems like the ''rubber boot'' scenario waiting to happen

[Mark Parlee]

Nick
I do not see why you would take it to the inside.

I think the face of the sheathing with the lap is the way to go

[Top Notch]

Appreciate people's input. My questions remain:

Does anyone know any reasons why the flashing is taken to the inside face of the studwork?

Does anyone see problems with requiring it be brought to the face of the sheathing and lapped with housewrap ?

Nick Coulson

The intent of the code is to prevent water from entering the wall cavity. I believe the detail in your picture is wrong, the designer could have made a mistake.

[NW Architect]

We had another thread here on the same thing, except without the brick ledge. All were flabergasted. It just seems to be SE tradition. Who knows how these things get started

The plastic in your detail serves no purpose, really, and the only drawback is absence of bonding between the bottom course of brick and the foundation. Bottom of the sheathing only gets wet if the WRB is short - and that's a WRB problem, not a plastic problem.

With a 2-brick ledge, all one needs to do is extend the WRB over the face of the back face of the ledge, and one is good.

If there is no brick ledge THEN one needs a good stick-on membrane and/or sheet metal flashing all around the base. That's how its done around here. We spend the money on metal, not on the concrete forming. Go figure

[Top Notch]

I remember that thread NW but not the detail, I think its was Pete Engle who referred to the flashing detail as a "row lock" in where the brick is not bonded to the masonry cap. I still find that odd, according to that explanation the brick rested on a copper flashing with-in a mortar joint by gravity. That doesn't seems right to me.