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Patio Doors That Make You Weep

image of a patio weep hole; flashing; weeping; weep hole

Several of our clients have experienced water intrusion around sliding glass patio doors.  There is a mixed bag of flashing problems that can cause water intrusion.  Flashing materials, weep holes, and weep ropes are used to drain water that gets behind the masonry.  

In this image, the black material beneath the vertical bricks is the flashing that drains the water out and away from the building.  The weep rope is supposed to help draw water out from behind the masonry to the outside.  This main issue with this picture is that the weep hole looks small and the rope looks pinched.  

Here we can see that a translucent sealant was placed right on top of the flashing.  This sealant prevents the water from moving to the outside and traps it behind the masonry.  The sealant was only present towards this end of the patio door and not the other.  Inside, a lot of moisture was found directly behind this section of the door and not on the other side where the sealant was absent.

At this property some flashing was present but it did not extend far away enough from the masonry.  The flashing should come out and overlap.  In this image, rust is visible between the door frame and the concrete.  This is a good indication that moisture is actively getting into this patio door.

Here, it appears that new mortar was placed to seal up the weep hole.  It may have been confused for just a simple opening. They probably sealed it up trying to prevent water from coming in, not realizing they were preventing water from coming out! Weep holes don’t always contain weep ropes.  A mesh screen can be placed over the weep hole to prevent insects and debris from entering the cavity. No matter what type, they should not be sealed shut.

In all of the properties shown above, there was moisture detected behind the patio doors.  To prevent mold growth you need to address the underlying moisture issue that is causing the dampness.  If there’s moisture surrounding a glass sliding door, it would be wise to check out the exterior of the patio door to determine if there are any anomalies that could cause water intrusion.  

Joel Silva

Joel Silva

Joel Silva is a Project Manager that performs indoor air quality assessments with a specialty in mold and bacteria. Mr. Silva holds a Bachelors of Science degree in Biology from Aurora University and he is a Certified Indoor Environmentalist (CIE) which is a certification from the ACAC. Prior to working at Indoor Science, Joel did microbiology work in the quality assurance department for a food manufacturer. During school, he also interned for the Chicago Department of Public Health. In his words... “As a child, I had an interest in science specifically in the biology of the natural world. Besides working for Indoor Science, I enjoy running outdoors, competing in races, lifting weights, practicing yoga, reading, and visiting breweries all over the country.”

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