House Shopping 101: Towards Maintenance-Free
by Keith Tripp, 2020
House Shopping 101: Towards Maintenance-Free. In this hustle and bustle world, maintenance is a dirty word. Houses are certainly heading towards maintenance-free as exterior cladding materials evolve, but some materials still have relatively short life. Here’s a few things to look at to assess maintenance requirements.
#2: Exterior wood and paint. Exterior wood can survive many years if it is installed in a position that allows it to drain. When ends of wood are butted so they trap water, or a horizontal surface is not sloped, the wood will rot. 10-12 years seems to be about the length of time for significant rot to occur at wood that is frequently wet. The North exposure may rot faster because of slow drying, and the South exposure may rot faster because the sun will accelerate paint deterioration. Most exterior panel boards are composite materials designed for exterior use, but real wood is still used as trim. Real wood was used on window frames through the 80s and 90s.
Painting may slow the rot, but will not prevent it on poor installations. When house shopping, even for brand new houses, watch out for wood that may require painting, especially in hard to reach places like dormers. It is common for me to find wood that is freshly painted and filled with sealants or other materials, but is completely rotted underneath. Garage doors may contain real wood, and this is subject to rot, especially at the lower door panels. Door frames on balconies are high risk, as are porch columns.
# 1: Exterior sealants (caulking). Life expectancy of sealants varies greatly based on quality of material, installation details, and exposure to the sun. Sealants on new houses will have the shortest life because wood shrinkage is causing movement. Sealants on new construction can separate within the first couple of years. More commonly though, failures in the form of separation will be noticed around the 7 to 10 yr age on the sunny side of the house, and 10-15 years on the less sunny sides.
The photo is at a 15 year old house, South facing window. In addition to the age and the South exposure, the gap at this junction was probably too wide for sealant, even before shrinkage of the wood frame. Sealant performance is specified based on maximum joint width . Backer rods ( foam material that acts as a filler in a wide joint) can be used, but there is still a maximum joint width recommended by the material manufacturer.
Flexible sealants have been used for many years. Newer materials exist that could displace the use of the sealants, such as gaskets that expand to take up movement, but they are not in use by the tract home builders.