substandard contractor work?

[carwashguy]

I had a flat rubber roof replaced at work and I have some concerns about quality of workmanship.  The first half of the roof they put down was a fairly cold day with the temp between 37 and 42 degrees.  There are some bubbles under the rubber that I am concerned about. The contractor said that the adhesive went down a little thicker than they prefer because of the cooler temps and the bubbles I see are from the off gassing of that thick adhesive layer.  He claims that the gasses will "seep out"  with the temperatures get higher".  The temperature has been typical New England weather with some day in the 30-40's and some has high as 70 degrees.
He is expecting full payment since he has finished the work.  My questions is: should I accept his explanation?  Should I be concerned about the quality of his workmanship, the second half of the roof looks perfect.

[CLETUS]

Is that EPDM? 

We have some bubbles on our roof, not nearly as bad as yours though...

What kind of warranty? I think ours was 15 years...

[Splinter Puller]

I would find out what brand of roofing the contractor used... Firestone or Carlisle etc... and send that manufacture a picture of the installation asking them if they would have any problems honoring the warranty of the installation.  If they are ok with it, then your ok.

[Admiral]

I would find out what brand of roofing the contractor used... Firestone or Carlisle etc... and send that manufacture a picture of the installation asking them if they would have any problems honoring the warranty of the installation.  If they are ok with it, then your ok.

This  ^^^^^^^^^^^^^^  But get it in writing from the manufacturer.

[barnowl]

... He claims that the gasses will "seep out"  with the temperatures get higher".  The temperature has been typical New England weather with some day in the 30-40's and some has high as 70 degrees.
...

Perhaps he right, but common sense would ask if the roof is water tight, one would think that it's air tight as well.

Unless the gasses "seep" into the structure, and not through the membrane.

[whatline]

Doesn’t matter if you send pics. Both Carlisle & Firestone whom also manufacture versico and mule hide will tell you the contractor is correct about the gassing off. That said there are a few more blisters than an experienced crew would have had regardless of temp.

[FireWood]

I'd hold back 25% of payment until the roof is done "gassing off" or a rep from the membrane manufacturer inspects and gives you written confirmation that the installation meets the warranty requirements.

[whatline]

Here’s the way the warranties work. First in order to install a warrantable roof the contractor has to be an approved installer. Top tier installers can offer longer and enhanced warranties. A second tier guy may only qualify to install say 10 yr. warranty jobs. Second the manufacturers charge the installer a fee. Typically we under .15 per sf. The installer builds that into the price they give you and it should have been a line item in your proposal or contract. Third the installer has to fill out an NOA notice of award with the manufacturer. Fourth the roof needs to be inspected for the warranty to be valid. You may not like the looks of the blisters but if you have a watertight installation....that is what the manufacturer warrants. I’m not saying I agree just telling you what happens