Help Identifying Commercial Roofing Products


I have two different roofs and questions (Pictures attached) and need help “IDing” a few things.

  1. The first is a 60mil TPO roof fully adhered to 2" of ISO. The ISO board is attached to a concrete deck using Olybond Low-Rise Adhesive. The roof is 2-3 years old.

With that in mind my question is, there are lines perfectly spaced across the roof that is just trapping sediment, dirt, etc. Obviously not harming the integrity of the roof system but I cannot figure out what causes those lines.

  • It isnt the TPO bonding adhesive the lines are to perfect and the bonding adhesive is applied in a random pattern.

  • It isnt the ISO as they are 4x8 sheets not strips of ISO

  • It isnt the Olybond somehow becoming visible bc it is applied in a ribbon pattern opposite the direction of the lines that are showing up.

So… What could it be???

2) The second question is there is a Mod Bit roof that has this reflective/metallic sheeting applied at the edges of the roof, up the curbs, up the parapet walls. I am unfamiliar with this material. Does anyone have experience with this stuff? What purpose is it supposed to be serving, who manufactures it, etc. Not all that common in my area of the country.


The second one looks like Siplast Veral aluminum.
Was the TPO installed with bonding adhesive? Did you use a machine to run the bonding?


Im so excited with this post.
I do not know the answer to the questions
But happy for someone to ask and hopefully someone will know. I want to know!

My opinion is it could be the outline of the decking.
But if thats the case, how does it outline through ISO?
I dont know.
I would open it up and i think i would see right away.
Was that some fancy wagon that applied the foam?
I havent seen that one if so.
That is cool!
But could also be the culprit.

I dont know who made the alluminum covered self-seal modified bitumin.
But i love that stuff!!
My suppliers dont carry it.
MFM makes a similar product,
Its much, much thinner though
But great in the right hands.
It will last 3-5 times past its warranty, if you know how to install it right. Clean surface and a lil bit of heat.

I do feel the very center of the 3rd picture
Exposes a leak.
Where the pipe is coming out of the roof is a
"Pitch pan"
It needs to be filled with tar and “feathered” right up the pipe.
I would also seal around the bottem of the pitch pan also.
Then i would put granules on it at the same time.
You could skip that part and save 50 dollars or so but it would make the repair last longer.


The bonding adhesive was roller applied so it couldn’t be the culprit.

After calling around I believe it may be the facer/backing on the polyISO. I have been told that this is a characteristic of less expensive brands of ISO. Certain brands tend to crease over time not realy an issue except not very aesthetically pleasing.

Also, what is the supposed benefit of the aluminum being applied to the Mod Bit? reflectivity?


The lines in the iso are from the manufacturing process. The bottom facer is on a screen and the iso is applied over it. The top facer is then applied and compressed to the proper thickness. The lines are from the screens.

Yes, the aluminum faced modified bitumen is Siplast. Veral. The facer easily delaminates if the sheet is heated too much.


Welcome to the Forum Gil.


Gil is correct on both answers. The ‘row lines’ in the ISO can we less apparent on one side of the board vs the other- mfgrs actually print “this side down” on the board in an effort to help combat this and increase membrane to substrate adhesion.

Siplast is one of a few manufacturers that makes the foil faced SBS product, it also comes with copper and stainless foils on it.


Thank you. Glad I found this forum.