Flat roof advice in Brooklyn: two verydifferent quotes

Hello roofing experts. I live on the top floor of a small self-managed building in Brooklyn. We’ve begun to see leaks and water damage, and I’ve volunteered to gather estimates for a new roof. All we know about the history of the building is that it was built in the late 1800’s, and the owner who converted it into co-op apartments did so 30 years ago, and he’s not put a new roof on for at least those 30 years.

So far, I have two estimates and am in the process of getting a third. The estimates are very different, and one also includes the cost of repointing the bricks on the parapet wall, but for now I’d love any and all opinions and advice on the types of materials these companies propose using, and their process. Both companies come highly recommended. The biggest difference in their process is that one recommends putting a new roof over the existing roof, the other recommends tearing off the old roof.

Will uniformly spread a layer of modified bitumen adhesive into which we will embed one layer of smooth, modified bitumen roofing. Each sheet to overlap the preceding sheet by 4 inches and all seams will be firmly sealed.
We will install three new course fabric flashings around the entire parapet walls, base of skylights, vent pipes, and all other objects that come above the roof line, to consist of two layers of asphalt fiber cement and one layer of asphalt saturated fabric to be properly staggered in length and height to secure a water-tight roof.
Where needed we will cover the roof side of parapet walls and chimneys with two layers of asphalt fiber cement and one layer of asphalt saturated fabric. We will cover the roof side and top of parapet walls (with pre-cast stones) with new modified bitumen roofing.

Tear-off old roof. Install a 2" insulation, install a pealing stick bay sheet. Install new SBS cold rubberized roof white colored. Install SBS rubber around the parapet walls, starting from the roof surface going up 12", attaching them with termination bar with concrete nails.

Thanks so much in advance for all of your expert advice!

#2 is the better long term solution. I’m not a big fan of cold applied or Peal-n-stick but I don’t think you can torch apply in Brooklyn anymore. Too many loose monkeys burnt down buildings sigh.

Tear off is always the way to go IF you have the money.

Thanks Tar Monkey. I’m still learning all of the terminology, and have read many mixed things about torching. So the process for #1 definitely IS torching, just by the very nature of the materials used? Just want to be sure I understand. The roofing company for #1 did mention torching when they came to look at the roof, and mentioned something about how b/c it is technically illegal, they do it as minimally as possible. If anyone else was telling me they wanted to use an illegal roofing process on my roof I’d run screaming, but this is a family-owned company, they’ve been in business for over 50 years, and they come highly recommended by multiple people, which makes me feel like at least they know what they’re doing.

And I’m torn about the tear-off issue, too, since this highly reputable company (#1) didn’t suggest doing it. For their job, it would cost about $7,000. For option #2, (which also includes brick pointing and a new drain) it would cost almost $40,000. Would love more thoughts from all of you folks out there.

No, both quotes you have been given are for cold process. I was simply saying that I trust torch applied more but I think it’s illegal in your area.

Get several quotes but the roofing process you’ve already been offered is probably your best option. (cold applied SBS)

You can hit Werkheiserroofing.com if you need a little more info. I am unsure of Brooklyn building codes though.

ok here i go!
#1) how are the seams going to be sealed? a 3 course "flashing"will last about 1-2 yrs @ best.this guy is a rip off.
#2) first off sbs is not “rubber” its a type of modified bitumen.this is what i would have suggested.the tearoff route anyway.im not a big fan of overlays.
did these contractors mention if they are insured or bonded. also. did they mention if they are approved by the manufacturer to install the product they are trying to sell you?do your research and get 4 more estimates.

what roofboss said

I stopped reading at the point you said one wants to do a roof-over, while the other wants to tear-off the existing roof. Without reading any further, I can tell you that it is almost always best to remove the existing roof first.

at the very least,bad areas would have to be repaired for a layover :wink: