Installing 2x4s over shingles is a common method for creating a level surface for roofing underlayment and shingles. This technique is often used when the existing roof sheathing is damaged or uneven. 2x4s can also be used to add strength and rigidity to a roof structure.
There are several benefits to installing 2x4s over shingles. First, it creates a smooth, flat surface for the underlayment and shingles to adhere to. This can help to prevent leaks and improve the overall performance of the roof. Second, 2x4s can help to distribute the weight of the roof more evenly, which can reduce stress on the roof structure. Finally, 2x4s can help to insulate the roof, which can reduce energy costs.
