Weep Screed Blocked: Check For Stains and Mold

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Blocked weep screed is noted in many home inspection reports, but generally does not greatly effect the desirability of the home, however, it can occasionally be serious. It is estimated that 95% of homes on the market in many areas do not have weep screed or has weep screed that does not conform to current codes.

What is weep screed?

Weep screed is a piece of metal near the foundation of a home that has a couple of purposes:

  1. It provides a straight line stopping point for the base of the stucco wall.
  2. Allows excess moisture to escape or drain from the area behind the stucco membrane.

Why do you see the comments on Home Inspection Reports that say the “weep screed is blocked” ?

First, the comment is put into the home inspection report to let a buyer to know that occasionally a problem may develop due to the blocked weep screed and that the current building code has requirements regarding the weep screed.

Buyers may wish to ask the home inspector if it is common for him to see blocked weep screed and how many people did something about it.


Weep screed

Weep screed

Having some clearance under the weep screed is desirable for best performance.

Generally having 2 inches clear to hardscape, like concrete, pavers, etc. and 4 inches to the dirt / soil level is desirable.

Mold in a house

Mold and Mildew Issues

Dark discoloration or stains on stucco

Should there be a dark type of discoloration on the bottom area of an exterior wall, then this may be an indication of mold and mildew. When moisture gets trapped because of the weep screed being blocked, then some of the moisture may enter the wall cavity.   (Read about getting rid of mold)

Moisture in the wall cavity can lead to the framing deteriorating and wood rot as well as the insulation becoming wet. This type of condition is more likely to occur if the house wrap or building paper behind the stucco is torn or punctured which provides a path for moisture to enter the wall cavity.

Mold on a home wall

Check the interior wall for stains, discoloration or a musty odor

In exterior areas where the stucco weep screed is blocked or has mold and mildew evidence; check the homes interior wall opposite these areas for evidence of mold or mildew. Also check for musty odors, for they can be an indication of hidden mold and mildew.

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