metal roof repair options

huangyhg

metal roof repair options
we are searching for repair options to our 28 yr old r-panel metal roof.  my preference is to remove and replace with a standing seam system.  however, the folks who write the checks want less expensive alternatives.
we're doing a structural analysis to determine if the frame will support a standing seam overlay.  foot traffic precludes a spray foam system.
i've come across a system that involves spraying a synthetic rubber coating over the top of the existing roof (after prepping it).  it seems like a good theory and i wanted to know if anyone had any experience with these sorts of systems.  the vendor, of course, promises the world.
or, if anyone has any other suggestions to keep the rain out, i would like to hear them.
regards,
jc

basically the problem boils down to doing a life cycle cost analysis.  my gut feeling is that over the next twenty years, the retrofit, standing seam roof is the best bet, but not the cheapest first cost.  the trouble with the "exposed fastener" type metal roofs is the tempature changes that the roof goes through during the course of year.  the screws work loose and punchture the spray-on membranes.  
whoever you pick to do the roof, be sure to get lots of references and check the references.  i recently did a damage investigation of a standing seam roof retrofit where the contractor installing the roof did not follow the manufacturer's installation instructions.  the roof was fine for about four years, then just the right wind storm from just the right direction blew it off.  the clips used for the roof were fine, but the installer only put one screw in instead of the two required.  inspection, inspection!
good luck.
jcovey,
we installed a rubber membrane over two of our roof sections five years ago and are very happy with it.  
the original metal was a standing seam type and the first step was to place styrofoam panels between the ribs.  they then added another layer of foam across the entire roof after which the membrane was placed and glued.  
we have tried the sprayed material and were not happy with it.  we have tried brushed asphalt coatings and have not been happy with them.
in the past much of our foot traffic was due to breaking up ice dams.  with the extra insulation and continuous covering, we no longer have the dams.
we have one section of roof under membrane that has lasted over 20 years (installed in '78) and is still looking good.
griffy
jheidt, griffy,
thank you for your input.  j, i've got the same opinions as you regarding the fastener problems as well as the standing seam retrofit being the best option.  we are enlisting the services of a roofing consultant to help with preparing the design and bidding documents and to monitor and inspect the installation of whatever system we select.  
griffy, i'm glad to hear your feedback on the spray on system.  i didn't mention it, but we're considering the membrane option, too.  factory mutual is our insurance carrier and they get a funny look on their face when a membrane roof is mentioned.  i don't know if it's the wind uplift concerns or the additional decking required to lay the membrane over the ribs.  i've also been told that the membrane roofs are incredibly slippery when wet and i don't want to create a safety hazard for my guys who are performing maintenance to rooftop equipment.  
again, thanks,
jc