The answer to 'roof decking cracked' is that cracked roof decking is a common roofing issue that needs prompt attention. Roof decking is the structural layer that supports the roofing material, and cracks can occur due to age, water damage, or structural issues. Symptoms include visible cracks, sagging, or uneven areas on the roof.
In many cases, cracked roof decking will require professional repair or replacement. Attempting DIY fixes is generally not recommended, as the decking is a critical structural component. A roofing contractor can assess the extent of the damage, make any necessary repairs, and ensure the roof is properly supported and waterproofed going forward.