Two good options, two different bets. Here is the honest comparison rather than the one that ends with whichever product carries the better margin.
The case for TPO membrane
TPO reflects a large share of incoming solar radiation, which on a flat commercial roof translates directly into lower cooling load through the summer. Lifespan runs 20 to 30 years, installed cost $6.00 to $11.00 per square foot.
TPO is hot-air welded, not glued. A technician runs a robotic welder along the lap and the two sheets fuse into one. That is why seam probing is part of any honest inspection.
The case for torch down modified bitumen
Modified bitumen is forgiving on low-slope residential decks and on the small flat sections that so many valley homes have over a patio or addition. Lifespan runs 15 to 25 years, installed cost $5.50 to $9.50 per square foot.
The cap sheet is torch-applied: the installer melts the underside as they roll it out so it fuses to the base. Done well it is monolithic. Done in a hurry it traps air.
Where each one lets you down
TPO fails at the seams when they were welded too cool, too hot, or too fast. A correct weld tears the sheet before it tears the seam. By contrast: Blistering and seam lift are the usual complaints, and both trace back to moisture trapped under the cap sheet at install.
What to specify either way
- Specify 60 mil minimum. 45 mil exists and is cheaper and you will meet it again sooner than you want to.
- Two-ply is the standard worth having. A single-ply torch application over a bad substrate is a short-term answer.
- A written scope that names the underlayment, not just the surface material
- A per-sheet price for deck replacement, agreed before tear-off
How we would decide
If you are staying in the house past the next fifteen years, buy the longer service life and stop thinking about it. If you are likely to sell inside five, the cheaper assembly done properly is the better use of the money. Slope, framing capacity and HOA rules narrow the choice faster than preference does.
Questions we get asked
Which one is cheaper over thirty years?
Divide installed cost by expected service life and the gap narrows sharply. The cheaper roof up front is frequently the more expensive roof per year.
Can I switch from one to the other?
Sometimes. Moving to a heavier assembly means confirming the framing can carry the load, which may require an engineer. Moving to a lighter one is usually straightforward.
Does either affect resale?
A documented, permitted roof with remaining service life affects resale. Which material it is matters far less than whether the paperwork exists.
Working with a Sunland roofer
All American Roof Repair & Commercial Roofing has been on Sunland roofs since 1986. We cover Sunland and the surrounding communities including Burbank, Lake View Terrace and Tujunga, and every estimate we write names the material, the underlayment and the flashing scope so you can compare it line for line against anyone else's.
If you want a second opinion on TPO roofing vs torch down roofing, call (818) 275-0921 or run your address through our instant quote tool for a ballpark figure before you talk to anyone.
Need a roofer in Sunland?
Free inspection, honest scope, and an estimate that names the material and the flashing work. Call (818) 277-6626 or get a ballpark in about a minute.
