Recently, my hometown paper, The Columbus Dispatch, published a story (www.dispatch.com/live/content/local_news/stories/2010/10/30/house_mold.html) about a family who bought a home in Dublin, Ohio, and after moving in discovered, upon removing some carpet, that there was dampness and mold under the carpet. Further investigation revealed deep problems within the home.
The home, about 11 years old, was clad with stucco and brick. Due to improper installation of the cladding, problems were occurring within the wall cavity. The lack of proper flashings, missing weep holes and flashings, as well as improper installation of the stucco cladding, were at the root of the problem. After finished surfaces were removed, it was discovered that mold was growing in the walls and the OSB sheathing was deteriorated as well. The homeowners have had to move out while repairs are made. They are living temporarily in their real estate agent's farmhouse until they can raise enough money for repairs. The cost of the repairs is estimated at $100,000-$120,000 on an original purchase of $285,000.
In the article, they state that they understand that their home inspection did not include a mold investigation. Their home inspector currently is helping them resolve the issue. There is certainly a question as to whether other homes in the neighborhood have similar problems.
Personally, I did some consulting for a homeowner who had problems with ice damming. He had some drywall removed because he was concerned about hidden damage and discovered mold within the walls. The cladding was a combination of cultured stone and plaster stucco. Not only were the windows leaking due to improper flashings, the home had a polyethylene vapor barrier and mold was growing on the OSB sheathing due to the fact that condensation was occurring within the wall cavity. Repairs for this home were over $50,000 and were paid for primarily by the homeowner, with some minimal assistance from homeowner's insurance. The home was 11 years old. There was absolutely no visual indication of any problems within the home. If it weren't for the ice damming, this problem never would have been discovered.
I believe there probably are thousands of homes in any given locale that have hidden problems related to improper installation of cladding materials. These problems are not necessarily discoverable, due to their concealed nature, by a home inspector doing an inspection to the ASHI Standards. Whether home inspectors should be including mold or indoor air quality evaluations, and if these tests would accurately discover these conditions, certainly is a subject for legitimate debate.
We certainly can and should be pointing out the implications of windowsills that don't drain properly and missing weep holes, flashings and weep screeds. Yet, there are elements of a cladding installation that cannot be known without destructive testing. Some may believe there is a balance that must be reconciled between unduly alarming buyers and providing the necessary information to understand the risks that hidden problems may exist.
There is little doubt that when home-owners discover that their home is unlivable due to a hidden problem, they feel that their inspector should have caught it. Home inspectors, beware.