I've got an LA-based warehouse client with an existing 30yr roof that needs to be replaced, it's about a 100K sqft and not leaking much but definitely on its last legs. I've received a number of different bids from roofing vendors but I'm not savvy enough yet about roofs to decipher what is the most appropriate.
Basically, I need to decide between a Title 24 white modified bitumen roof system or a 2-ply polyester reinforced emulsion roof system.
The APP torch down modified bitumen roof is slightly more expensive, but it's a whole new roof and the warranties I've been seeing are 7-10yr labor / 10-12yr material.
The emulsion system is basically a coating system reinforced by polyester and installed on top of the existing roof: existing roof, emulsion, polyester mat, emulsion, polyester mat, elastomeric coating. Labor warranty of 5 yrs / material warranty varies.
Both sides are pushing their products and talking down the other, thus I'm a bit confused. Emulsion opponent says that it will not last as long as modified bitumen roof and needs regular re-coating within the material warranty period to keep up the warranty. However, I'm also being told that even a modified bitumen roof requires re-coating every 6-7 years.