How to find a contractor who actually does attic ventilation calculations
Most roofers only want to slap down shingles and leave the same day instead of handling complex ventilation work or tricky setups like rubber roofs. This makes it nearly impossible to get proper calculations and installation done without hiring the wrong tradesman. Homeowners end up stuck trying to figure out which professional to call and how to get the job done right.
What the numbers show
Counted from the threads quoted below. How we count
- This comes up 26.2× more often in r/Roofing than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Trying to get advice and recommendations from online forums like RedditDid this help you?
- 2calling a rubber rooferDid this help you?
- 3Asking the roofer to show manufacturer detailsDid this help you?
- 4Insisting that Z closures need to be sealed at the baseDid this help you?
- 5Cutting open the ridge ventDid this help you?
- 6Installing roof fansDid this help you?
- 7Cutting out the gable ventsDid this help you?
- 8Using continuous ridge vent with soffit intake and bafflesDid this help you?
- 9Switching vent types during a roof replacementDid this help you?
- 10Verify that soffit vents are open and not blocked by blown-in insulation or paint.Did this help you?
- 11Install soffit vent baffles to properly direct outside airflow up the rafter bays toward the ridge vent.Did this help you?
- 12Add insulation and a vapor barrier directly to the AC ductwork to stop condensation, rather than relying on attic ventilation.Did this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Not sure who to trust on this. A few years ago my 30 year old roof was replaced. House is located in Houston, TX where the attic gets hotter than satan's butthole. The original roof had attic fans and no ridge vents. The roofer recommended that we take out the attic fans and put ridge vents in instead so that's what we did. Recently my trusted HVAC technician did an inspection of my system in the attic and noted that condensation is building up on some of my ducts and says the ridge vents aren't providing enough circulation and I need to put the attic fans back in, but when I ask roofers about that they say I shouldn't do both as they counter-act each other.”source ↗
“When i moved into my house and the ropf needed redone i tried to fix ventilation this way. The roofer cut holes in my solid wood soffit, put a soffit vent along the soffit to allow air to flow through the large holes, then installed baffles on the inside to ensure continued airflow with insulation right next to it. They also fixed a basically non-existent ridge vent by making it larger.”source ↗
“We converted ours to ridge vent and they left the attic fan in place.”source ↗
“I don't know how to vent them through a rubber roof. Which tradesman would be the best person to call to do it.”source ↗
“I'm struggling just to find a contractor willing to do a proper calculation and the work. All they wanna do is shingle it and be gone the same day.”source ↗
“Does a regular non-perforated z panel under the ridge cap provide enough ventilation simply by being over a striated panel? I’m wondering if my roofer is totally incorrect or am I?”source ↗
“even though there is a ridge vent along the top of the house they never cut the actual vent.”source ↗
“There are also two gable vents installed on the outside on opposite sides of the house that are not really cut out either.”source ↗
“I currently have attic ventilation problems and I’m getting my roof done soon.”source ↗
Where this came up
People with this problem also raised
- 4How to ventilate an attic with no open soffits?
- 12Are powered attic roof vents actually worth it?
- 3Roof vents installed off-center and poorly aligned
- 6Why is my attic apartment so hot in summer and cold in winter?
- 7Are open cavity vent returns and exposed pipes normal in new construction?
- 2How to add a vent when you can't reach the stack