“As previously stated by others, once these foam roofs leak, the water is in and under the foam. All wet foam and the foam over the wet areas must be removed before any other repairs are effected”
There is another possible solution available.
If the decking is in good condition and they only are looking to remove trapped moisture I have found installing sheet metal vents (almost like a Swiss Cap) will work but it can take years (depending on ambient temperatures and huminidity levels to allow all the moisture to evaporate BUT it will stop blistering on BUR systems so it should work here as well.
Doing a complete rip up can really get into big bucks which may not be in the budget at this time.
Suppose they put a layer of 3/4 CDX or even wonder board with vents to help remove trapped moisture using probes or similar moisture seeking devices to find the hot spots and then just cover the existing with say and EPDM or other single ply system and treat the older lower roofing membrane as added insulation?
Sort of like a “Koppers” KMM type with an upside down insulated roof held down with river bed ballast
This could give them about 8-10 years relief time to budget for a complete rip off.
They could even if local codes permit use a very thin insulator between the new and existing roof if compatibility is a problem and rather then using a torch down type of single ply either a cold applied bitumen or asphalt or even pitch mopped applied then use gravel to keep the roof from floating away during the really hot summers
With proper pitch pockets and gravel stops and all kinds of games one can play with various types of roofing options the old roof could be left in place.
It all has to do with design weight like and usage like weather protection or promenade etc.
The one great quality no one menthioned is this system does not have fish mouths but it does seem to have its share of alligatoring.
Don’t you just love roofing terms