Manufacture not using thier own specs

I was called to bid a job on the building of a roofing manufacture. Of course they want to use only thier products. However the building is very old and it has a smooth built up roof. They want to do an overlay with there epdm and they don’t want to use any iso or wood fiber board. There reason is they only need 10 yrs out of these roofs. They plan selling or demolishing the building within that time. They currenlty lease some space and those tenants are geting wet and are complaining. This company no longer uses this building for thier own needs. There only concern is keeping there tenants dry and spending as little as possible. The local inspector looked at thier roofs and said to use 060 epdm and fully adhere w/ bonding to the existing roof. The deck is light wieght concrete and the existing system is 90% moisture free. He does want a couple of wet areas tore out. i gave them a bid to layover w/ 1/2inch wood fiber as well as a bid to tear off. They compared it to my competitors bid which was bidded for adhering directly to the existing roof. They still want to go with the adhering to the existing roof. They want me to submit a bid for doing just that. I have never done this though i have seen it done before. Does anyone know from expercience how long it lasts? What do ya say do i do it or walk away? They do want a leak free warranty and they do fully understand that this is not the correct way to do it but the inspector says it should be able to be made leak free.

Hello Frank, Chad here in MO. I definately think that you should give them a bid with a singleply coating system. The system wold be a fully adhered system as well as cheaper than a tearoff or new built up. Give me a call.