What TPO Costs per Square Foot in the Valley — The Short Answer
What moves the number on a TPO roof in the Valley, and why two bids differ by thousands.
Price is the first thing anybody wants and the last thing most contractors will commit to. The working figure for a TPO roof in the San Fernando Valley is $7.50 to $12.00 a square foot installed over a prepared deck, 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
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 the San Fernando Valley changes the figure
Summer is the problem here. The Valley runs ten to fifteen degrees hotter than the coast and holds it for weeks, so a roof surface that reads 90 degrees in Santa Monica is well past 160 in Van Nuys by mid-afternoon. Everything on the roof expands into that heat and contracts again overnight, and it is that daily movement, not the peak temperature, that opens laps and backs fasteners out. Most of the housing went up between 1950 and 1975, which means original decking, undersized ventilation and at least one previous layer that somebody roofed straight over rather than tearing off.
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 the San Fernando Valley the thing to watch is attic temperature and intake ventilation, because a Valley attic that cannot breathe cooks the underside of the roof as hard as the sun cooks the top.
Free inspection, drone photography where access is difficult, and a written estimate with deck repair priced per sheet. No obligation.