Mold and Stucco

I've been meaning to post some information on homes with stucco that are having problems with mold. I had to collect some information first.

Typically, my feeling is that stucco is a very good building material. Real stucco (vs. synthetic stucco) is basically cement. Because of that, it's usually a good building material and it needs very little maintenance. Stucco has been used on houses Columbus, Ohio area for decades. and dates back hundreds of years to Europe. It does take a little maintenance, because it can crack and peel since it is cement, but it can usually be readily fixed. And it's practically impervious to weather conditions.

Home inspectors will tell you that in-and-of-itself stucco is a good building material. The problem that inspectors and builders are finding is that it's not being installed properly. What does that mean? Basically, it's not being sealed and/or flashed properly around windows and doors, and water is seeping in behind the stucco and into the interior walls of the house. This can, and has led to major damage to homes, including a proliferation of mold because the water is in the wall cavity and can't dry out. So you get homes that basically rot from the inside out in some cases, and that are harbingers for mold. All of this happens unbeknown to the home owner.

So is this something new? What changed? Stucco has been around for a long time, why are we just now hearing about this? It appears that they way they install stucco may have changed, and that may be based on builders methods or local building codes. However, one of my inspector friends says that this may be a larger problem than anybody knows because it's so hard to detect. There may be homes that were built many years ago that have issues yet the owners are unaware. And by the time it gets detected there can be serious damage that has already taken place. The Columbus Dispatch recently posted a couple of articles regarding the problem. One is from October 2010 and one is from December 2010. Here they are:

http://www.dispatch.com/live/content/local_news/stories/2010/10/30/house_mold.html

http://www.dispatch.com/live/content/home_garden/stories/2010/12/12/moldy-moderns.html

If you read these articles you'll see that stucco problems can be very hard to detect, as I mentioned earlier. And it also appears that this is not limited to any particular builder, price range or area. It appears that this can affect any home built just about anywhere.

If you take a look at the pictures below you will see something really interesting. These pictures were taken locally. First, look at the picture in the upper left corner. From a layperson's perspective it looks fine and normal. It's a little hard to see, but there doesn't appear to be anything wrong with the stucco from this view. Now look at the (2) pictures to the right. These were taken using an infared camera (I had my picture taken with this, camera, I looked like something from Predator). The camera doesn't detect water, it detects heat variations. A camera like this is useful for other applications as well, like heat loss from a roof, due to improper insulation, etc. Regardless, you'll see the blue in the pictures. Blue, meaning cooler. You would expect to see blue at the window, windows typically loose heat. But notice the stucco under the window. It is possible that there could be heat loss based on improper insulation in the wall cavities. However, the blue here was because of moisture, which is at a lower temperature than the wall or the stucco. And you can see that its basically in a drip pattern.

It the same scenario in the (2) lager pictures in the second row. Same house, same problem. Looks fine in the first picture, blue in the second picture, indicating moisture.

The next two pictures down show small cracks in the stucco. Are these the cause of the moisture? Likely not, because most of the problems are with the sealing around the windows. This is likely a crack caused by the water. Keep in mind these are just my interpretations of the pictures and the problem. I was not present when these pictures were taken.

The last two pictures show where water has affected the flooring and the framing in the home. It appears that this was not detectable without removing drywall. Again, it's really hard to detect.

My reason for posting this particular topic was to make sure that sellers, and especially buyers, were aware of these problems related to stucco. If you are a home buyer you need to know of things like this so you can better make an informed decision when purchasing a home. Because I work with only home buyers I try to stay up on issues like this for the sake of my clients. Information is power, especially when it come to buying a home. The more information, the better.

These pictures were provided by David Tamny, with Professional Property Inspection. If you have any questions or concerns please feel free to contact him. He has become somewhat of local "expert" on stucco and mold issues. FYI, there is no specific test or inspection for this sort of thing. Typically, an inspection can include a visual inspection, pictures with an infared camera such as this, mold testing by scraping and air-quality sampling, and more invasive procedures like removing drywyall, framing or wall board.