Here in New England the reason most paint peels is because the paint coating has become too thick and inflexible. Old homes wearing their original siding and trim can have over 15 coats over them – as the wood expands and contracts with temperature and humidity changes, the paint film breaks; once broken, peeling is inevitable. On newer homes peeling paint tends to be related to construction issues; the use of softer pine wood for trim, the failure to back prime siding and trim, the failure to prime cut ends. Primer is the first line of defense against moisture; applied to all 6 sides of wood it helps stabilize and minimize absorption – leave one edge or side unprimed and the consequences are almost immediate. We spend a lot of time repairing prematurely failing wood on newer homes, sadly.
In the book Water in Buildings, the architect William Rose makes a strong case for unsealed basements being the cause of paint bubbles or blisters. Simply put, consider the inhabited house in winter as a chimney – heat rising through the roof pulls in replacement air through any opening – including through porous basement walls and floors. Multiplied by the pressure differential of the moist air inside evacuating into the dry winter air, a house is essentially vacuuming moisture from the ground and exhausting it through the exterior walls and roof, and in many cases, saturating the back of unprimed clapboards – as this moisture travels through the wood it can cause significant blisters – we’ve seen some whoppers in our time – if you pop them in the spring water is released!
Unfortunately once the house is built or remodeled incorrectly it isn’t actually feasible to prevent exterior paint peeling – it just becomes a feature of the exterior that requires seasonal touch ups. On older homes we avoid over painting; we apply one coat where possible, two only if necessary as we are trying hard not to thicken the coating on the house unnecessarily.
At Catchlight Painting, we are the exterior home painting experts. We understand the science of paint, how to fix peeling paint on drywall and achieve a beautiful lasting result. Call us or email us today. We’ll happily wax on about the topic until you have a full understanding of why the paint on your home is peeling.