What effect can moisture absorption have on roof deck expansion?

Moisture absorption can lead to roof deck expansion, which in turn can cause shingles to buckle at the panel edges. When a roof deck absorbs moisture, it swells due to the expansion of the materials, particularly if the deck is made of wood or engineered wood products. This swelling can create uneven surfaces and stress points beneath the shingles.

As the deck expands, the shingles are not able to move freely with the changes occurring below. This constraint can lead to buckling, particularly at the edges where the shingles are fixed down tightly, and the expansion forces are greatest. Buckled shingles can then lead to water infiltration and further damage if they're not addressed, compromising the integrity of the roof system overall.

This understanding of moisture effects highlights the importance of proper ventilation and moisture control in roofing systems to prevent these issues from arising.