Cool Roof Savings on a Southern California Warehouse — Common Mistakes
What moves the number on a TPO roof in the Lankershim corridor, 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 TPO roof in the Lankershim corridor 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 Lankershim corridor changes the figure
Along the Foothill corridor the buildings are largely commercial: big low-slope areas carrying rooftop plant, walked on regularly by trades who are not thinking about the membrane. Dust off the slopes settles on the surface and washes into the drainage with every storm. Older commercial stock with large low-slope areas, parapets, and equipment that needs servicing.
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 Lankershim corridor the thing to watch is membrane condition around the rooftop plant, parapet terminations, and every drain and scupper on the roof.
Free inspection, drone photography where access is difficult, and a written estimate with deck repair priced per sheet. No obligation.