Sixty Mil or Eighty: Choosing TPO Thickness — Budget Planning
What moves the number on a TPO roof in North Hollywood, and the line item that decides it.
Nobody enjoys asking what a roof costs, and very few answers are useful without context. For a TPO roof in North Hollywood the honest working range is $7.50 to $12.00 a square foot installed over a prepared deck. What follows is what sits behind that number and why two quotes on the same property can be thousands apart.
What you are actually paying for
Membrane thickness, insulation build-up and the number of penetrations to detail around set the price. Sixty mil rather than forty-five is a small percentage on the quote and a large difference in puncture resistance.
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. Weld testing is the item to insist on. A probe run along every seam while the crew is still on site costs nothing and finds the cold welds that would otherwise be discovered by a tenant in December. 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
- Seam integrity, probed along the full length rather than spot-checked
- Punctures and abrasion, especially on traffic routes to rooftop plant
- Membrane shrinkage and any resulting tension at the perimeter
- Flashing and termination bar at every wall, curb and upstand
- Drain sumps and clamping rings, checked and clear
- Fastener plates showing through the membrane surface
- Weathering and chalking of the surface, particularly on exposed elevations
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
TPO is a good system installed properly and an expensive mistake installed quickly. Seams and punctures decide its life, so protect the surface and test the welds. 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.