Why Do Wood Fibers In Wooden Roofs Shrink

Once the nail heads are exposed water running down the roof can seep into the building around the nail shank resulting in rotting of underlying roof building materials and causing moisture damage to ceilings and paint inside.

Why do wood fibers in wooden roofs shrink.

In some climates certain times of the year are much more humid than other times. The ones exposed to more air and heat near the outsides of the pile had dried in unexpected ways. In turn this causes the logs to contract in radius however the length of the logs remains the same. If the bulging is less severe try a couple of simple alternatives to see if you can correct the problem without replacing the wood.

As the logs in your log home dry out over time the wood fibers shrink. Two reason s wood shingles aren t used anymore. Wood fibers always shrink in the radial direction. The amount a piece of wood will shrink lengthwise called longitudinal shrinkage is so small typically about 0 1 to 0 2 that it is usually inconsequential to the volumetric shrinkage however plywood greatly benefits from the low longitudinal shrinkage of wood layers of wood veneer are glued together with the grain direction of each ply oriented perpendicular to the adjacent ply.

Many years ago some shingle manufacturers promoted fire resistant roofing materials that were made using asbestos fibers within the shingles reinforcement. Eventually the loss of the oils causes asphalt shingle fibers to shrink and wood shingles to rot exposing the nail heads under the shingles. The water causes the fibers in the wood to swell and shrink. First they are more expensive.

This would caused the surfaces that dried quicker to shrink at a greater rate than the surfaces that are protected. As the logs shrink in. A board that is severely bulged will most likely need to be replaced. Wood is a finite resource and quality shingles have gotten more expensive as the.

Why do logs shrink. Personally we ve experienced this phenomena every year we ve been in our home. However shingles containing asbestos were phased out in the 1960s and asphalt shingles were made fire resistant using safer inert mineral stabilizers. Wood that expels moisture will shrink.

There are two ways to do this put in firring nailing though nails are not used any more for this strips or purlins in steel frame construction on the roof to support it or place the metal roofing directly on a flat surface like foam insulation board or the roof sheathing with roof water barrier in the correct position in the layer. Wood with a moisture content that is out of balance with the surrounding air can either take moisture from the air or return moisture to the air. This change in size is caused by moisture reduction and shrinking of the wood fibers and most commonly it results in hairline cracks in painted joints and separations in the panels of doors. These fibers are cylindrical in shape and have a long axis through the log.