Edge for residential Low Slope roof?

Hello - My contractor had a roofer put down Roof Fast Cap Sheet (by IKO) on a backyard low slope roof structure. I believe it is a 1 layer self-adhesive over plywood. My concern is the edges - they don’t seem properly finished to me. Also does this much material overhang make sense or can it be trimmed back?

I would love any help, thoughts or ideas.



I’m not very familiar with that material but I would assume that you would want to cut it back with about a 1" or 1 1/2” overhang on the rake edge. As for the flashing, yes it would have looked much better to enclose the end of the plywood using flashing but won’t necessarily cause any damage right away. The flashing protects the end grain of the plywood so in the long run it is a better idea but not an absolute must for short term. At this point I think you are stuck with no flashing but I have an idea that may work, instead of cutting back the roofing you could attach a 1x2 for a shadowboard to cover the end grain.

I would check that application and make sure you have a base sheet. I don’t know of a self adhesive cap sheet that can adhere to plywood without one. That overhang tells me the installer has no clue. Cut that back before it blows off or bends over to the fascia. Just a side note, as of 2012 code calls for eave metal. I would be suspicious about the longevity of this.

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Simple answer: wrong.

You will not find a single manufacturer’s construction detial that allows for what is shown in the picture.



Roof fast can be installed direct to plywood if a primer is used.
When you need a new roof, you will likely need to replace all the plywood if the roof has to be removed. But it seems to work the few times I did it years ago.
You should have some edge metal added onto it. It can be installed and patched into the roof.

I’m genuinely curious as to how that would be done.

IMO it is the flashing details that are the major weakness of the self adhered modified systems, walls, edges, penetrations, weird crap we all encounter…

I would fold the sa over the edge, then nail a drip edge over it. Finish it off by stripping the drip edge with 4" piece of sa set in flashing cement. It may cause a bit of ponding with the back water lap but other than replacing the whole thing that’s the best option IMO. And i don’t think it will have much effect on the performance of the roof in the long run.

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