Epdm problem / solution

New EPDM roof (Fully adhered to 1.5 ISO) 6 sq. Roof
Installation errors caused bubbles/blisters everywhere.
Likely errors - to much glue in some areas, and rolled in to soon.

Solution - Installing a new sheet of EPDM over existing after
slicing/cutting out all bubbles. w.(Splice Adhesive)

Reasoning - If the current sheet is pulled up the face
of the ISO will come off/ruined etc.

Your thoughts on this?


You better slice and dice the rubber all over not just the bubbles. Condensation will occur.

Speculation… someone else did the damage and you are trying to help the owner…

Everyone should be glad its 600 SF not 6,000 or 60,000!!!

If it is truly that bubbly ISO may not be a complete loss pulling up the sheet as it may not be that adhered. And if it only ruins a few sheets swap em out, if it defaces many sheets a layer of 1/2" over the top and try again.

Metal could be an issue if it is on and taped in.

Personally I would not cut and lay another layer over the top without something (ISO) between and that would be second choice to the above.

Are you seriously considering using splice adheasive for the whole sheet ? I will give you a tip, you can use bonding “yellow” . Just use seam tape or splice adheasive for your laps. when you glue remember to go thin,consistant and always broom it in. dry tack to the touch.

How long has the problem been present?

I have had the situation you mentioned before but have found after a few cool nights it streches into place, then only a couple of bubbles may need to be patched in.

I agree with you and VT on the causes of the problem.

If you do choose to lay over the existing, cut the existing to prevent a double vapor barrier.

I used to promote fully adhered as a better system. Now after a few years of singleply installation experience, I am not so sure about that. Everything is situational. If it’s a tear off with a nailable substrate I almost always now promote mechanically attached. Of course if it is a concrete or gypsum deck I promote fully adhered. Also if the roof will be used as a deck or garden I also promote fully adhered. Lay overs you could go either way, with mechanically attached or fully adhered. From a point of view of horizontal water migration, it may make more sense to install fully adhered on a lay over.

Jim B, I was instructed once by Firestone to do a 4 square patch on a large 200+ square bowling alley. There was a persistant leak the field rep just could not figure out. He sent out a request for bid and that was basically his spec, wash, FA patch and cover tape the edges as necessary. Seems to have worked, at least for a short run, this was 2 years ago. For waht it is worth his diagnoses and proposed repair was way off the bat, but I bring this up to mention that though I too have never read an official spec to do it, the idea is out there and it seems to work.

I didn’t broom it myself so I can not comment on that, other than to say the guys didn’t complain any bit. My 32+ year veteran roofer thought it was odd we were using bonding adhesive instead of splice/seam adhesive, but I suppose the splice adhesive would be insanely expensive on 400 sq ft, but BA was the specification. Then again he never once used any Self Adhering products like seam tape before coming to work for me in 2004 either.

I did perform a final inspection and I had no complaints as to how it looked. There were no bubbles, wrinkles etc… If I ever get a chance to inspect again (probably not due to various “political” reasons) I will post a pic of the aged product. I’m curious myself to see how it holds up.

How old are the pics in relationship to the installation completion? I mean were these pics taken immediately after completion, or were they pics taken yesterday? I am assuming the pics were taken during installation based upon the lifted membrane in pic 2.

If you go back today I would suspect some of the bubbles would already be laying flat. You can likely broom out or roll out any of the remaining bubbles. It doesn’t look that bad. It’s not a picasso, but it certainly does not warrant an additional layer of membrane. Worst case scenario if it doesn’t lay flat in a few weeks, and you have tried to sweep and roll, a few patches would be all that is necessary.

Next time don’t use so much glue and punch your supplier in the face if they don’t bag your ISO. On the description line of my purchase orders, when ever I order ISO it says in the description for each and every iso product (Please make sure all insurlation is bagged and covered.) I had that problem recently where most of the iso was factory sealed, but a few pallets were split, and sealed around the sides with plastic wrap, but the tops were left exposed. It rained after we loaded to roof, not to mention the morning dews, a few days later we started roofing. We had to take a few panels and let them dry out in the truck a few days before we could use them. Minor inconvenience for us.

[quote=“onarooftop”]New EPDM roof (Fully adhered to 1.5 ISO) 6 sq. Roof
Installation errors caused bubbles/blisters everywhere.
Likely errors - to much glue in some areas, and rolled in to soon.

take your time. It will be lay down soon[/quote]

If the seams and penetrations are holding up, and it is not leaking, I would not touch it.