Can Metal Go Over Existing Shingles? — Long-Term View
What moves the number on a metal roof in North Hollywood, and what a quote should already include.
Price is the first thing anybody wants and the last thing most contractors will commit to. The working figure for a metal roof in North Hollywood is $12.00 to $18.00 a square foot installed, and the rest of this explains what moves it, because the same roof can differ by half again depending on things you can check yourself before anyone quotes.
What you are actually paying for
Standing seam costs more than exposed-fastener and is worth it in almost every case here, because concealed clips let the panel expand and contract without loosening anything. Panel gauge, coating grade and the number of penetrations to flash around account for most of the rest.
Where quotes diverge
Deck repair should be priced per sheet in writing before work starts, because it is the one item nobody can size until the covering comes off. Thermal movement is the detail that decides everything. A long panel in this climate grows and shrinks measurably between a July afternoon and the following dawn, and a fixing system that does not allow for that movement will fight it until something gives. It is also the line that most often separates two quotes that looked identical on page one.
How North Hollywood changes the figure
North Hollywood takes the full inland summer with very little relief after dark, and the ultraviolet load on a south-facing slope here is as hard as anywhere in the county. Asphalt ages from the top down under it: once the granules have gone the mat underneath turns brittle and starts to crack. Mostly single-storey post-war housing with later additions, which puts a transition detail in the middle of the roof where two eras of workmanship meet.
What we look at before quoting
- Fastener condition on any exposed-fix section, including washer hardening
- Clip engagement and any sign of thermal binding along standing seams
- Seam integrity down the full run, not only at the visible ends
- Coating condition, with particular attention to cut edges and scratches
- Sealant at penetrations, end laps and every transition
- Panel oil-canning, which is cosmetic but can point to fixing problems
- Corrosion at eaves, cut edges and any point where dissimilar metals meet
Common questions
Why is one quote thousands cheaper than another?
Almost always because it excludes something. Compare the deck repair rate, the layer count and whether flashing is being replaced or reused before you compare totals.
Can I get an accurate price without an inspection?
You can get a range. You cannot get a price, because nobody knows the deck condition until the covering comes off, which is why the per-sheet repair rate belongs in the estimate.
The honest summary
Metal is the longest-lived option available here, but only if the fixing system suits the movement. Ask how the panels are held down before you ask what they cost. In North Hollywood the thing to watch is granule loss on the sun-facing slopes, and the junction where an addition meets the original roof.
Free inspection, drone photography where access is difficult, and a written estimate with deck repair priced per sheet. No obligation.
More on Metal Roofing
- Rust and Corrosion on Metal Roofs in Sherman Oaks — Materials ComparedMetal Roofing
- How Long Does a Metal Roof Last in Sherman Oaks? — Myths and FactsMetal Roofing
- Thermal Movement: Why Metal Panels Need Clips — Signs to WatchMetal Roofing
- Does a Metal Roof Make a House Hotter? — Homeowner ChecklistMetal Roofing