SIDING AND PAINT FAILURE

Included in this issue of the newsletter of the Michigan Chapter of the Community Associations Institute is an article that explains much about paint failure on wood, derived from formal research.  Moving into the fall, when exterior paint projects have mostly been wrapped up, it may seem an article late in coming.  But the importance of planning ahead cannot be overstated.  Rather than soliciting bids for the year 2000 with the same old specifications, or leaving the specifications to the painter or carpenter, it may be beneficial for your community to be involved in setting new criteria for the materials to be used.

If you believe your community’s buildings are suffering premature paint failure, please read “Making Paint Stick to Wood Siding & Trim”.  In doing so, you may discover the causes for your paint and wood rot problems were not what you had in mind.  Some other causes for wood failure are mentioned herein.

This summer Parker Services replaced oriented strand board lap siding on thirty-five detached condominiums in Novi, MI.  The cost to the community was significant and could have largely been avoided if the Association had employed foresight.  Granted, much of the problem could be blamed on an apparently inferior siding produced eight or so years ago by a manufacturer that has since settled a class-action lawsuit over the product.  And the lap siding had rotted in a few areas because the installers were careless with their nailguns.  They ignored manufacturer warnings against nailing through exposed surfaces.  Wood lap siding is rigid enough that nails are only needed along the top, concealed edge.  When a nail is required or desired through an exposed surface, it should be covered with caulk to prevent moisture infiltration, as paint isn’t always enough to stop that infiltration.  The builder also failed, according to some folks who were around during construction, by not applying a finish coat the newly installed wood siding on some buildings.  The factory finish was already a desirable shade.  Yet when those and other buildings were painted a few years after construction at Association expense, the quality of the paint was not monitored.  It was inferior and thin.

In replacing rotten wood this summer, a common problem encountered with the horizontal siding was a sponginess at the bottom edges.  Fungus took life in the oriented strand board here and seemed to hold moisture in the wood.  Even in a hot, dry week, fifteen feet above the ground, where sprinklers and ground moisture could not wet the siding, you could peel out damp layers of the siding from the bottom edge with your fingertip.  A better coat of paint on the edge five years ago may have kept the destructive fungus from finding a home there so soon.

Additionally, a fungicide added to the paint may have been helpful.  You might be told when seeking advice from your favorite paint vendor that high-quality exterior coatings need no extra fungicide.  Indeed those coatings contain fungicides... but is there enough of the proper quality?  For many years we have applied a solid-color stain to t1-11 siding at a one hundred eighty-eight detached unit community in West Bloomfield, MI.  The subdivision is set beautifully within mature woods.  Before we completed the first five year coating cycle for the Association, problems developed at some units we coated the first and second years of the cycle.  Black mildew covered walls on many homes on the shady streets.  Perhaps the trees and wetlands create a more humid micro-climate on those streets.  At any rate, our paint supplier suggested a possible reason for the mildew that would have been incorrectible, but was vehement that the stain contained sufficient mildewcide.  And our paint supplier did not offer a mildewcide even if we wished to add one for safe measure.  However, the Association knew it was better to act, and they urged us to try something.  We contacted Jomaps, Inc., in Alpharetta, GA, and ordered a mildewcide, which we hopefully added to the stain.  Prior to applying the stain on the heavily-mildewed buildings, we killed the visible mildew with a bleach and water solution, as in the years before and the years since.  It has been five years, and, unalarmingly, only small, isolated patches of mildew have appeared.

This summer, at the community in Novi where we replaced so much lap siding, the alterable flow of trickling water contributed at least as much as any other component to siding failure.  Consider what can happen to a fireplace chimney:  rotted lap siding, vertical 1” x 6” corner trim boards, oriented strand board siding substrate, and even structural members.  Where a chimney protrudes from an eaves wall of a house, the eaves troughs that drain the adjacent roof butt against either side of the chimney.  The tiny amounts of water that drain between the sides of the chimney and the gutter end caps over the years create paths from the outside into the several components of the chimney.  Poor-quality or no caulk at siding-to-trim and trim-to-trim joints contribute to the destruction, allowing small but clear paths for water to infiltrate the chimney.  Poor flashing details at the corners of the chimney that join the roof also allow clear paths for water to rot the chimney from the inside out.  The results we saw this summer were sometimes devastating, though the appearance of the chimneys did not always disclose what was within.  For some chimneys, it cost thousands to restore what a hundred dollars of details would have prevented.