Cedar shake splitting occurs when cedar roofing materials crack along the grain due to aging, weather exposure, or moisture cycling. Splitting is a natural characteristic of wood expansion and contraction, but excessive cracking can compromise roof performance.
As cedar absorbs moisture and later dries out, the repeated expansion and contraction place stress on the wood fibers. UV radiation and long-term weathering further weaken the material, increasing the likelihood of splits.
Minor surface splitting may not immediately affect waterproofing, but larger cracks can allow water penetration beneath the shakes and into the underlayment system. This can eventually lead to leaks and structural moisture damage.
Improper installation, low-grade cedar products, or inadequate maintenance can accelerate splitting. Roof sections exposed to direct sunlight often experience more rapid weathering.
Localized shake replacement is commonly used to address damaged sections before the problem spreads across larger roof areas. Regular inspections help identify splitting early and maintain roof integrity.
