Why Tie-Ins Leak
The seam where a new roof meets an old one is where most addition leaks begin. Common causes include new shingles simply butted against old ones, missing leak barrier at the junction, step flashing skipped where the addition meets a wall, and low-pitch porch roofs covered with shingles that cannot shed water at that slope. Another frequent issue is a new gutter line that dumps water onto the old roof instead of into a downspout. Any of these can show up as a stain on a brand-new ceiling within the first heavy rain.
How We Build a Watertight Tie-In
- Weave or lap new courses into the existing roof rather than butting them together
- Install leak barrier across the junction and in any new valleys
- Use step flashing and counterflashing where the new roof meets walls
- Choose a membrane or metal for low-slope sections
- Extend ventilation so the new attic space is not left without airflow
Matching the Existing Roof
We try to match shingle color and profile, but older shingles fade and some lines are discontinued. If a match is not possible, we discuss options such as reroofing a full slope or the entire house so everything looks uniform. Our Olive Branch roof installation page describes the systems we install.
Reroofing at the Same Time
If the existing roof is approaching 20 years old, it can be smart to replace the whole roof during the addition. One crew, one tear-off and one warranty instead of a patchwork. For homeowners planning an addition, see our room additions service; for replacement details, our residential roofing in Olive Branch.
Common Questions
Can you roof an addition another contractor framed?
Yes. We check the framing and deck, then install the roof and tie it into the existing structure. Coordinating early with your builder helps the schedule.
Should I replace my whole roof when adding on?
If the existing roof is near the end of its life or a shingle match is impossible, reroofing everything at once is often worthwhile. If the roof is fairly new, a careful tie-in is usually enough.
Can a sunroom or patio cover have a shingle roof?
Only if the pitch is steep enough for shingles to shed water. Low-slope covers are better served by metal or a membrane.