Manufactured Home Roof Penetrations

I see a lot of roofs on Manufactured Homes similar to what’s in the attached picture. I’m curious if anyone else sees something wrong with this roof aside from the poor workmanship of laying down the asphalt shingles. I have

speculation of defects with the roofing vent penetrations, but see this so often I’m questioning “is it really a defect, or am I just missing something in my training?”.

Aside from not enough roof vent boots and wavy shingles, I don’t see a problem.

More roof vent boots recommended.

Wavy shingles not a problem except poor workmanship.


Welcome to our forum, Gregg!..Enjoy! :smile:

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I agree with Larry.
There may not be enough roof vents. There is a formula for calculating roof ventilation if you want to look into it. 1/150 rule.
Don’t overthink this. The wavy shingles are just that, not a defect.

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Morning, Gregg.
Hope this post finds you well.

Observation: Tree limbs above roof.
Tree limb in contact with roof.
Roof deck vents not properly aligned.

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Thank you all for the warm welcome and replies. I agree with all your commentary and expertise. Personally, if this were my roof I would have never paid the contractor and believe that the tree needs to be cut below the roofline - I only mention that, as I see some discoloration in the galley from always being in the shade potentially leading to a future problem. Regardless, that is not my primary concern. I’m just not used to seeing the shingles butted up against the vents on the downside. I’m more accustomed to seeing the flashing over the shingles on the downside.
And yes, ventilation is lacking.

The flange should be over the shingles on the low-side. However, sometimes roofers will just cover the low-side flange with an extra shingle for aesthetics (and the flange is actually atop the main course).

Secondly, a wavy running course of shingles is not necessarily a defect unless your shingle adhesion strip is off course or your fasteners are exposed. I watch courses closely for that reason.

As far as ventilation goes, it is hard with premanufactured homes. Was there an attic? intake vents? Vaulted ceilings? But, you can refer it for further evaluation if you think it is inadequate.

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As for trees, I use 12 feet above the roof and 6 feet off the sides. That is just my opinion. Others will vary for sure.

Always look at the similar houses around the one you’re inspecting. Often they will tell you how the one you’re inspecting was built originally, before any changes took place, such as reroofing and the roofer decided to eliminate a bunch of vents, or when someone had an issue and they added a bunch of vents. Look at the house to the right, look at the number vents on it:


Thank you all for your replies. Greatly appreciate all the input.

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