How to find plumbing vent- Buccaneer 1983 sw

I have a Buccaneer single wide year 1983, model MH-2663 according to the title. 14’x62’. It has 3 steps to walk up to the kitchen and the living room has high ceilings. The existing roof was almost flat, just a slight dome and in 2 levels since one is higher over the kitchen & living room.

I am hoping someone has one of these or perhaps a year close to 1983 that might use the same plumbing venting that could enlighten me.

The roofer put on a new metal roof but did not cut any vents into the new roof. He has since moved and does not respond to my question. I assumed there is some kind of plumbing vent through the existing roof such that it would have been removed to make way for the 1.5” insulation sheet to lay on the current roof and then the metal sheet above (and of course the wooden framing to hold it). The tenants are using their plumbing ok for the last 3 months since the new roof was added. Unfortunately, I don’t have pictures that include enough of a roof view to know for sure if there was a vent up there or not.

I’ve read there can be “check vents” in mobile homes, however the plumbing was replaced in the house rehab shortly before the roof and who knows if the same arrangement was kept (same guy that did this). I will find out how the plumbing looks soon. Another roof guy that can add the venting said he’d have to take the metal sheets off until he reaches the point where the vent is since I don’t know where to point him to. (If that’s the best way then that is costly considering I just paid to put the metal on I didn’t want to pay to take it off and back on.)

Does anyone have this model to be able to say how the venting was done in the house? And if there is a plumbing vent through the roof can you tell me any kind of offset to be able to find where it comes out through the roof? (“ 2 feet from edge of house and 3 feet from end of bathroom window closest to the living room”)

Would the tenants have plumbing issues if there is really a vent on the roof that is covered by a 1.5” foam insulation sheet? Currently the area where the soffits go is open so air is probably flowing under the new metal roof without issue. Maybe that is allowing the vent even though the top of the roof has nothing cut out yet?

An added bathroom fan I am hoping the person can go from the inside of the house to cut through to vent that through the roof. So I “think” the plumbing vent is the problem issue since it wouldn’t be visible on the inside of the house.

[if you have this model, I am going to get a different range exhaust so I can vent it through the wall instead of cutting through the roof it seems less traumatic at this point; I don’t need the vent for the gas furnace as that is replaced with electric.]

Thanks so much for any insight on solving this question.

Your drains might not flow as quickly without correct venting.

If the check vents are code, just install one under the sink and abandone the old vent pipes going up towards the roof

It might also be possible to run a snake, from under the sink, up the vent pipe. You could listen for where it hits on the roof, cut and reseal accordingly.

Thanks so much for the advice. I am in the queue for a plumber to come and see if everything uses check vents or if they can be added to skip the roof business. And I also asked him about your idea about using a snake to find the vent pipe if he thinks the roof venting would be better for certain items. We’ll see what he finds out. Thanks again.