On any custom residential build, the exterior envelope is assembled by three or four trades whose work intersects at every wall-to-roof transition: roofing, stucco, windows, and exterior trim. The sequence in which these trades execute matters for the waterproofing of the assembly, the visible quality of the detail work, and the project schedule.
Here is how we coordinate.
The sequence we prefer
1. Window installation (rough opening flashed and windows set)
Windows are framed and set into the rough opening, with the flashing applied at the head, sill, and jambs per the manufacturer's instructions.
2. Roof underlayment and edge flashings
The roof underlayment is installed across the deck, with the edge flashings (drip edge, rake metal, eave) integrated. This is the dry-in stage.
The underlayment carries onto the wall at the wall-to-roof transitions, lapping over the wall sheathing or wall WRB (water-resistant barrier).
3. Stucco lath and scratch coat (first pass)
The wall lath is installed up to the roof edge, with the scratch coat applied. The stucco scratch coat laps over the underlayment that the roofer has carried onto the wall — the underlayment is the substrate's waterproofing layer; the stucco is the wall finish.
4. Roof field material
The visible tile, slate, metal, or shingle is installed on top of the underlayment. The field comes up to the wall, and the roofer's apron flashing terminates against the scratch coat.
5. Stucco brown coat and finish
The wall stucco continues over the apron flashing, with the counter-flashing cut into the stucco wall finish at the appropriate elevation.
6. Exterior trim
Final trim, fascia, corbels, and decorative elements are installed after the wall finish and the roof field are both complete.
Why this sequence
The principle: each trade's work creates the substrate for the next, and each waterproofing layer is protected by the next layer.
- Window flashing is in place before any roof work begins.
- Roof underlayment is the WRB at the roof-to-wall transition; it must be in place before stucco.
- Roof field material caps the underlayment and integrates with the wall finish.
- Stucco wall finish creates the counter-flashing terminal.
What goes wrong
Stucco scratch coat before roof underlayment
The wall WRB is missing at the transition. Water that gets behind the stucco has no path to drain; it accumulates against the framing.
Roof field material before stucco scratch coat
The roof apron flashing terminates against bare lath or against the WRB without a stucco substrate. The counter-flashing cannot be installed properly; water behind the stucco bleeds against the flashing.
Exterior trim before roof field material
The trim covers the eave detail; the roofer cannot install the eave drip edge cleanly. The trim has to be removed and re-installed.
Windows after roof underlayment
The window head flashing has to integrate with the roof underlayment, but the underlayment is already installed below the window. The integration is awkward and often improvised.
What we ask the GC for
At the project's pre-construction meeting, we ask for a written sequence — typically a simple Gantt-style schedule showing the exterior trade sequence by week. The sequence should follow the order above; any deviation should be discussed and reasoned.
If the GC has a different preferred sequence, we discuss the implications. There are sometimes valid reasons to vary the order (a specific architectural detail, a permit-sequencing issue), but the variations should be deliberate, not accidental.
A note on solar and gutters
Two trades typically execute later, after all the above:
Gutters: after roof field is complete, before final stucco trim work. Gutters must integrate with the roof drip edge; the integration is part of the roof scope, not the gutter scope.
Solar: after everything else. Solar mounts integrate with the roof field; the mounts are the final integration before the system is energized.
A note on inspections
The dry-in inspection (after roof underlayment) is a critical hold point. Stucco should not begin until dry-in inspection passes. The GC's superintendent should be tracking this; we provide the inspection date once scheduled.
Filed under