Flat Roof Input

I don’t see many flat roofs. Usually the ones I see are pretty straight forward. This house was built in 2006. The adjacent neighbor has had some work done at the seams. Are the amount of blistering acceptable? Near the edge the bubbles are trapping water and causing a little ponding. Just looking for input.Roof%20Work Roof-1 Roof-3 Roof-4 Roof-5 Roof-6

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Afternoon, Robert.
Hope to find you well and in good spirits today.

Robert. This is a Modified Bitumen Membrane.
Observation: Blisters follow the sheathing joints. Various locations on the roof deck.
Failing, blistering seams at wall flashing.
Wrong Roof deck vents. Low profile roof deck vents are for sloped roofs. The deck pitch is not 4-12 or steeper.
Poorly stripped vents and chimney.
Loss of granules.
Suspect: 13 year old original roof covering. Old worn out.
Recommendation: You can write this up several ways.
Recommend a licensed roofing contractor:
1: Replace the roof immediately.
2: Provide a written evaluation of the roof covering, Modified Bitumen Membrane, and roof tuneup immediately prior purchase.
Act upon any recommendations provided by the roofing contractor.
Limitations: The roof was mounted. The entire roof surface inspected for defects and deficiencies.
Could not inspect the roof from the roof space. No access.


Thank you! Whenever I’m posting a question here it is always usually because I feel that the element is not acceptable, but like to have further input from more experienced HIs. Greatly appreciate the input from this forum.


A few blisters here & there don’t concern me.
This surface is screwed up, too many areas where it was not laid/installed properly.
The air can get pretty HOT & pop the blisters.

I write up blisters. Just saying.
If you look at the wall flashing, its gravel stopper roof edge flashing. Wrong type. Dams water. Water penetrates the bitumen leading to blistering, seal loss.

I can write this roof up hard. Amateur. Not professional.
As well. Modified Bitumen have a 10 to 15 year life expectancy.
Old, Worn Out.

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Thank you!

Thank you! Good specifics!

Thanks Marc!

Any narrative should be more spastic. I was generalizing.
Suspect: Membrane metal flashing seal moisture penetration. Various locations.
Blisters. Membrane metal flashing. Various locations.
Blisters. Various locations throughout the roof covering.
Do not box yourself in. If you have to enplane defects to a professional learn the terminology.

Good luck with all your endeavors.

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That is not a modified Bitumen Membrane

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Had to see from a pic. Sorry Robert if I am mistaken.
Here is an image of MBM.
Don’t keep us in suspense.

Marcel, what is it?

Improper installation of a 45 mil peel and stick white membrane similar to this. https://buymbs.com/p-113-mfm-peel-seal-self-stick-roll-roofing.aspx?vid=8891&utm_source=Google&utm_medium=Product_CPC&utm_campaign=8891&gclid=EAIaIQobChMI34W2jbWr5AIVDl8NCh0xWQZDEAQYASABEgJCnPD_BwE Or a type of TPO glued or peel and stick. But it definitely not a Mod. Bit…
But could only be sure by walking the roof which I can’t so your best bet would be to recommend a professional roofer to look at it.
It is not properly installed and will pose problems in the near future just by foot traffic.

Thank you Marc. I will note this. This particular material noted in the link has a 10 year warranty. So its due to be changed. Again, thank you very much!

Thanks Marcel. I should have looked at the vent pipe stacks. Ops.
Recommend further review by a licensed roofing contractor.vent%20stacks

Last month I inspected a modified roof. Granular was worn on 60% of the roof. Manufacturing defect.

Definitly looks like Peel and Seal , used it a lot on metal panel roofs

Really appreciate everyone’s input! What a great team and a wealth of experience! Thank you all!

Hard to tell details from my phone, but except for the color difference at seams, looks like at TPO type of roofing material. You probably need to get upclose to see how the seams are sealed and if there are fasteners at the seams. There are a ton of variables on commercial roofing and new products being released all the time. Product failures are not uncommon. Be careful describing what you don’t know. Best thing is to get a commercial roofer to do that part of the inspection if needed.


Thanks John!

Forgot to thank, Marcel. Thanks.