Best modified bitumen


I recently purchased a townhome in Washington DC. I’m getting quotes for contractors and most are pushing modified bitumen rather than rubber or EPDM.

What should I ask for when considering this material? 1,2,3 or 4 ply? I like the idea of a white granulated modified bitumen at 2 ply. The granulated is maintenance free and the white would reflect uv and heat better.

Also, how can I best negotiate with any potential contractor to get the price down? Thanks!

  • I also would like to ask whether I should get an APP or SBS mod. bit roof. Is the longevity better with an APP? Would a white 2-ply APP granulated mod. bit be the way to go?

I’ve met with two roofers so far who have quoted me 5,800 and 5,600 respectively for a roof on my 2,000sqft townhouse. I’d like to add 2 skylights on the roof as well which are ~600 a piece.

I am on Capitol Hill.

You can say “This is all I am willing to pay”…And if he is still in business when you have a problem,maybe he will come back…
That is the problem…People want a service,and want a good job,but want it cheap!You can’t get the best job done CHEAP…You can however get a quality job done for a reasonable cost…

poster could be a politcian.
first i do not like 2 and 3 layers of
anything unless it is hot tar with layers of
fiberglass mat.
torchdown last for 20 plus yr just one layer.
if water gets between the 2 layers it becomes
a big problem verses 1 layer were when it leaks
its easy to fix.

roll roofing whatever the style should not be

get one layer nice and tight with no leaks.
thats hard enough.


i have been doing modified for 25 + yrs & recommend atleast 2 inches of insulation, a 3 ply, with awaplan 170 white mop applied cap sheat on top of the 3 ply. it will look beautiful & outlast all of us. in that area call j&r roofing out of jessup, md.

I used to work with J&R quite a bit years and years ago. I believe they were the ones that roofed the White House if memory serves me correctly.

Anyway, I would recommend polyisocyanurate insulation, a coverboard like Densdeck or the cheaper alternative of perlite or fiberboard. Install a base sheet, 3-plies of asphalt BUR with Type IV felt and Type III asphalt, then install a reflective APP modified bitumen membrane. If you don’t plan on walking on your roof alot, and assuming you are willing to pay a little more, I’d recommend DerbiBrite by Performance Roof Systems. The APP membrane can either be torch-applied or set in cold-applied adhesive and only the laps torch fused together.


Also, how can I best negotiate with any potential contractor to get the price down? Thanks![/quote]

Get multiple quotes and make your decision. If you want a good job don’t be so cheap. Jeez.

Where is your building insulation located? On top of the roof, or on top of the ceiling?

If it is a 1908 townhome, then its probably on top of the ceiling. Polyisocyanurate bord would not do any good in this scenario.

I would, however, agree with making sure you get a nice flat secure substrate down, though. You probably have a plank roof deck at thi point. Plank roof decks tend to porpoise over time. New plywood, or better yet, like Cerb said, a Dens deck recover board then a base sheet and mod bit cap. I like two layers of modified if youre not going to set the base in hot tar.