If you’re having a new patio installed at your home, be sure your concrete contractor knows the required clearance to be maintained from the stucco weep screed. I consistently see improper patio installations while conducting throughout Riverside and San Diego Counties here in southern California.
Let me explain what a weep screed is. The majority of homes in this part of the country have stucco siding. At the very bottom of a stucco wall you will see a piece of metal trim- that is the stucco weep screed. What is it’s purpose? The weep screed assists in holding the stucco in place while it is being applied, but it also serves another purpose.
Most people I talk to think that stucco keeps water out of their home. Well, it doesn’t! Stucco actually provides a barrier to protect the exterior walls from physical damage. It also helps support the structure of a wall. But it does not hold water out! Stucco absorbs water! The component that actually keeps water out of your home is located behind the stucco- the building
paper. As water soaks into stucco, the building paper acts as a moisture barrier and drainage plane. The water drains out at the bottom of the wall through the weep screed.
At the home inspection featured in the video below, the patio slab has been poured too high and has buried the stucco weep screed. As water runs down the drainage plane behind the stucco and cannot exit at the weep screed, it may be pushed to the interior of the wall causing moisture damage and even mold and mildew growth in the wall cavities. A competent contractor will also make sure the patio slab slopes away from the house! Negative slope toward the foundation can also be trouble for the homeowner.
A stucco weep screed should have 2″ clearance from any hard-scape surface and 4″ clearance from soil areas.
Originally posted at First Choice Inspections.