Direct answer
There is no universal rule—but coordination matters more than which trade goes first.
If your roof and siding both need replacement, the best sequence is the one that avoids tearing into brand-new work later. On many homes, roofing first is practical because roof-to-wall flashing, gutters and upper-wall access can affect the siding scope. But siding may come first when wall damage, window integration or moisture problems need to be corrected before the roof-related details can be finished.
When roofing first usually makes sense
Roofing often comes first when the roof is actively leaking, near the end of its service life, or when roof-to-wall flashing will interact with the siding. Replacing the roof first can also keep debris and ladders away from newly installed siding.
Roof-to-wall flashing is the big reason
Where an asphalt-shingle roof meets a vertical wall, step flashing and kick-out flashing have to work with the wall's water-management system. If both systems are being replaced, planning those details together matters more than treating the roof and siding as separate jobs.
When siding first may make more sense
Siding can reasonably come first when removing the existing cladding exposes damaged sheathing, failed housewrap, window-flashing problems or other wall conditions that need correction. It may also make sense when the roof is still in good condition and is not part of the immediate scope.
What if the windows are being replaced too?
If siding and windows are both planned, coordinate them as one wall project whenever possible. Window flashing needs to integrate with the water-resistive barrier behind the siding. Installing new siding and then opening the wall again for windows can create unnecessary labor and extra detailing.
What about gutters?
Gutters often come off during roof or fascia work and are commonly installed after the roofline work is complete. If the siding project changes fascia, soffit, trim or downspout routing, coordinate the gutter plan before installation.
How Solaris approaches a multi-trade exterior project
We look at the house as one exterior system. If you are considering asphalt-shingle roofing, siding, windows or gutters together, the estimate should identify which pieces interact and establish the sequence before work starts.
The simplest rule
Fix active water entry first, then sequence the remaining work around flashing and access. If neither system is failing urgently, plan the roof, wall and gutter details together before choosing which crew starts first.
Research & Sources
- U.S. Department of Energy Building Science Education — Water Managed Walls. Background on drainage planes and wall water management.
- U.S. Department of Energy Building Science Education — Window Flashing. Guidance on integrating flashing with the wall drainage plane.
General homeowner education only. The correct sequence depends on the existing house and the exact project scope.