What I am curious about is who trains the new design engineers and architects in roof drainage?

After my 3rd day on this job I asked for a meeting with not only the designing engineer but the building owner and the architect.

I thought I at least owed these folks an explanation as to why I was going to hit the owner with extras on every single set back plus the majority of the other drain installations that were specified.

At this meeting I mentioned that each set back had only one drain and not every drain was the same size outlet.

What I did find was several layers of roofing membrane had been installed over the last 50 years and each time a new layer was put on the drain was sleeved thus decreasing the internal pipe diameter.

I also stated that to leave one drain on these set backs was not only asinine but border line criminal.

At this point the designing engineer jumped in saying that it is not even an option to install a second drain PLUS why have redundancy into the same pipe?

Not to be out done the architect then opened his mouth saying it is IMPOSSIBLE to install another drain on the 12th floor, 14th floor 16th and 18th floor set backs as the ceilings below was mirrored and some of the set back roofs were over computer rooms so access from below was impossible with all the duct work for the environmental controls.

I said OK then since these drains are "impossible" I will just have to charge double for each of these impossible drains to guarantee integrity of the roof on these set backs.

The engineer, now visibly upset, said "Why are you so concerned about something you should not even be discussing with us and especially with the building owners present."

I said "Sir, with all due respect, the Master Plumber has the final responsibility of insuring the plumbing/storm drainage system is installed, not only according to local code, but also so as not to allow a dangerous condition to exist due to faulty design."

With that the voices got extremely loud when the owner said "OK, hot shot, what is the problem as you see it?"

I went on to explain that one set back was 12 ft x 15 ft with a 4 ft parapet with a 2" existing drain that I had replaced BUT the piping below this drain was galvanized.

Even though I did take the precaution of snaking out these original pipes I know the inside is still reduced from years and years of accumulation of pitch (bitumen) and some gravel plus some internal corrosion.

Now lets also consider these drains are located below windows where folks do throw cigarette butts out and other debris and lots of pigeons do leave feathers behind and the new built up roof has gravel. We are now faced with the following conditions.

The hot tar roof will flow slightly every summer towards the low point (DRAIN) and the gravel stop and combination retaining ring can only hold so much back. Here lies a problem during the summer months.

During the winter snow and ice and again dead birds with other debris do collect around the dome of these drains.