Best Practices: Adhered Concrete Masonry Veneer

At the exterior steps on the house, we had to install aluminum flashing first to bridge over the sheathing transition.

After installing the weep screed, we cover the walls with housewrap and building paper ...

... and finally, install the rainscreen material.

Lath and the scratch coat will go over the rainscreen mat, followed by mortar and stone.

When we first inspected this house, most of the edges where uncovered and showing a lot of corrosion.

On this particular house, we found some attempt to install kick-out flashing above the gutters on roofs intersecting sidewalls. The kick-out shown had probably been installed after-the-fact, and it was much too little, much too late.

You can see clearly the tragic result of having such a wimpy kick-out flashing.

To do it right, we used a pre-formed kick-out flashing by DryFlekt at the base of the run.

The weep screed was followed by housewrap, black paper, rainscreen mat, and lath, all terminating to a weep screed at the roofline before applying the scratch coat.

Note the small cricket at the end of the valley above the kick-out. This is a variant of the kick-out and it performs the same critical task of diverting water away from the walls.

Around windows and doors, care needs to be taken to integrate flashing tape and housewrap. On the sides and bottom, the flashing should lap over the housewrap; but at the head, the housewrap should lap over the flashing.

At the head we install a weep screed, followed by metal lath.

Along window jambs and sills we install metal casing bead, spaced about 3/8-inch from the window flange.

After the stone gets installed, the gaps formed by the casing bead (14) will be filled with backer rod ...

... and (after taping off the windows with blue painter's tape) finished with a bead of sealant.

When we peel off the blue tape, we get a joint with crisp edges.

Nothing special has to happen where stone wraps around an inside wall corner. It is the same materials on each face of the wall, and there's no reason for them to move at dissimilar rates. But on the inside corner,one wall will get stone and the other has EIFS.

Ordinarily we would wrap the inside corner with housewrap (being careful to avoid having a joint), but in this repair we took extra care to ensure that no water got behind the housewrap by flashing the corner with tape and using a healthy portion of sealant, tooled over the tape, to create as good a barrier seal as we possibly could.

At the top of walls, we can bring the rainscreen mat right to the J-bead supporting the soffit.

A rake return, like the ones on the gable ends of this house, is a different animal. Here we have a vertical joint that will see its fair share of wind and rain.

Along the small section of roof above a rake return, we need a weep screed above the shingles.

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