Plywood Under Roof Is Soft

These soft spots usually form when the layer underneath gets soaked due to gaps in the shingles.

Plywood under roof is soft.

It determines how long your roof will last and how well it will protect the contents of your home. If you can tell there s a soft spot on your roof this most likely means that the substrate below the roofing material is damaged and deteriorating. The minimum plywood for roofing. Osb and plywood come in thicknesses ranging from 5 16 to 3 4 inch and the thickness needed for a particular roof depends on several factors including rafter spacing expected load and roof design.

Both osb and plywood for the roof have been approved for use so it may come down to what you feel most comfortable using. Why is plywood used in roofing. Most roofs have plywood sheeting underneath the roofing tiles or shingles. It is formed from multiple layers of wood bonded together with a glue and the grains run in alternate directions through each layer which ensures the board s strength is.

Over the period of manufacturer s designated roof lifetime of 25 30 years that plywood is exposed to heat in the summers heavy rains and the winter weather and cold dampness it brings. Rafters run from the peak of the roof. This can be a result of the plywood sheeting becoming wet from rain above or from moisture not being able to escape from below and leading to mold mildew growth on the wood. Roofs are framed with rafters or trusses which are rafters joined by internal braces so they install as a single component.

In roofing plywood is often selected due to its strength. Most roofs have plywood sheeting underneath the roofing tiles or shingles.