Roof vent caulking repair on TPO roof

[roadrunner255]

Hello all,

Quick question on repairing a 2" gap between a roof fan flange and the TPO roof.

I was up on the roof adding a Maxxfan cover and when inspecting under an existing Maxxfan cover discovered a not sealed 2" long gap.

Turns out there was a screw laying horizontally lodged between the fan flange and TPO roof.

I watched a couple RV101 (dicor) videos that suggest removing as much old caulk, cleaning with their roof cleaner, denatured alcohol, then use their self leveling caulk over screw heads and flange edge.

Question do I really need to purchase their cleaner (any substitutes) and does any adhesive need to be added between the flange and roof before I screw the flange back down?

Cheers!

[Bob Denman]

There certainly is no disadvantage to using their cleaner...
The roof of an RV is no place to be trying to save money. You need it to to be trouble-free.
Good luck!

[16ACE27]

Originally Posted by roadrunner255

Hello all,

Quick question on repairing a 2" gap between a roof fan flange and the TPO roof.

I was up on the roof adding a Maxxfan cover and when inspecting under an existing Maxxfan cover discovered a not sealed 2" long gap.

Turns out there was a screw laying horizontally lodged between the fan flange and TPO roof.

I watched a couple RV101 (dicor) videos that suggest removing as much old caulk, cleaning with their roof cleaner, denatured alcohol, then use their self leveling caulk over screw heads and flange edge.

Question do I really need to purchase their cleaner (any substitutes) and does any adhesive need to be added between the flange and roof before I screw the flange back down?

Cheers!

You know the cover is not supposed to be sealed to the roof? Obviously the fan flange is, but not the cover.

Originally Posted by Installation Instructions

5. A slight air gap between the MAXXAIR base and the roof after installation is normal and permits condensation to escape. Do not apply caulking to this area.

[Campnjoe]

Originally Posted by Bob Denman

There certainly is no disadvantage to using their cleaner...
The roof of an RV is no place to be trying to save money. You need it to to be trouble-free.
Good luck!

I agree. Out of all the things to skimp on, the roof is not one of them.

[roadrunner255]

Thanks all ordered a gallon of the cleaner and protectant, only a few $ more than the qt.

Btw, one one the vent screws was over tightened.
What do the screws thread into? Wood or metal?

I usually insert a few tooth picks but could also wrap the screw with some mig welding wire.

Thanks

[chunker21]

Originally Posted by roadrunner255

Thanks all ordered a gallon of the cleaner and protectant, only a few $ more than the qt.

Btw, one one the vent screws was over tightened.
What do the screws thread into? Wood or metal?

I usually insert a few tooth picks but could also wrap the screw with some mig welding wire.

Thanks

It's hard to say what thor does or doesn't do but previous RVs that I installed a maxi-type fan the vent opening was framed with a 2x3? lumber and the fan flange screwed into it. If you get the roof framing diagram from thor based on your model and vin it might detail the materials and type support up there.