Which flat roofing system?

Roofing/Construction Questions
#1

WHich flat/flatish roofing system do all of you use on a regular basis and why do you use it?

I have usually used either smooth torch or granulated torch. I am not happy with what i am seeing on the
“end laps”. End laps seem to be perfect up to the workmanship warranty(5 to 7 years) but have a possibility of failing before the 12 year manufacture warranty.
The last year or so, i have been installing both smooth and granulated if the homeowner can afford it.
Usually they cant.

The epdm roofs in my area seem to need a lot of patching to last a long time. but maybe it was cheap material or labor.

I want to learn a new system.

#2

peal n stick.

gweedo.

#3

If you don’t like end laps then use a cap sheet.

#4

5 ply coal tar pitch…cause it keeps the babies off the roof.

#5

Adheared EPDM would be my choice. I have been installing epdm for over 20 years with great results and with tape replacing glue a properly installed epdm roof can eaisly go past 20 yrs with minimal maintinance.
Tpo is exploding in the south and would also be a good system to learn.

#6

Right. I have been sayin to myself that i was going to do that. Haven’t done it yet.

I have increased my end lap from 8 inches
to almost 2 feet and also making it a round edge and not a square.

I have a system that i would like to use that would completly eliminate the end lap but it would be technically against the rules.

#7

TPO is fast becoming our membrane of choice. We still do alot of torch work, as well as self adhering modified.

#8

smooth or granulated torch down and self adhered 3 ply.

#9

EPDM is the most common way we do flat roofs, but have done them all at one time or another. Yes even coal tar.

#10

quote]I have a system that i would like to use that would completely eliminate the end lap but it would be technically against the rules.

roof-lover - I’m curious what your system entails. Would you be willing to share?

#11

I do mostly single plys such as tpo,pvc ,and epdm but will do bur as well.Roofing is a true art form at times there can be a host of variables in the mix.Mod bit to me is a no brainer a very simple system unlike sbs but as far as endlaps i will run ribbion rows everytime to cover those laps it looks good and i can walk away knowing theres no problems in the future.

Tiny

#12

There is only one system for flat-roofs, and that would be coal-tar pitch. You could use dead-level, but coal-tar would be what I’d spec. since it can handle the ponding on flat roofs. Of course, I’d rather install some tapered insulation to give the roof slope, and install a BUR with mod. bit. cap, or if I’m going single-ply I’d use a TPO.

#13

We’ve been doing alot of Mod-Bit installs this year. They all seem to be doing well. Is there some reason nobody recommends these types of roofs. We use a nailable base sheet with the SA Cap sheets.

#14

Coal tar pitch may be the premium flat roof but it is not “the only system”. Some times it is not even an option due to expense and the shortage of suppliers/applicators. A four ply cross BUR w/gravel is also a very good system, as is a three ply mod bit using a premium product like Siplast or Derbigum.
All you fellas recommending TPO/PVC need to read the article by Tom Hutchinson in the October edition of “Professional Roofing”…might set a few things straight.

#15

krakkerjak,

Read it and your point is?Every system has its faling points but i did agree with a couple of sections in the article.

#16

only the real good torchers get the end laps rite.
got to get it alot hotter.

gweedo

#17

[quote=“Krakkerjak”]

Coal tar pitch may be the premium flat roof but it is not “the only system”. Some times it is not even an option due to expense and the shortage of suppliers/applicators. A four ply cross BUR w/gravel is also a very good system, as is a three ply mod bit using a premium product like Siplast or Derbigum.
All you fellas recommending TPO/PVC need to read the article by Tom Hutchinson in the October edition of “Professional Roofing”…might set a few things straight.[/quote]

Yes, CTP is the only system for a “flat” roof as far as I’m concerned. I guess you didn’t catch the part about the roof being flat, i.e., no drainage. However, if it is a low-sloped roof I mentioned options that I would consider.

#18

The addition of “as far as I’m concerned” defines your statement as a personal opinion as opposed to your original post which defined it as an accepted fact. I have never been on a roof that has “no drainage”.
SPF with a ten yr recoat maint programme will also hold up against pitch. It is also cleaner, greener, and less expensive as well as easier to apply, provides way more of an R value and will stand up to ponding water with a urethane as opposed to acrylic coat. Fact.

#19

80% of todays roofers wouldnt know how to properly install a good ctp system that would last 50 yrs. todays guys are cut and run. they dont want to give 110%.take the extra step.ill bet most wouldnt know what an envelope on a ctp roof is for!99% of todays roof failures are mechanic related.“i didnt want to waste time doing it right” so i could go home 15 minutes early.or"you didnt show me that!i said it before and ill say it again.“they just dont make roofers like they used to anymore”

#20

I agree on the coal tar pitch roof with all copper flashings, and if I don’t envelope my installation, then I wouldn’t expect my envelope on Friday.
sux being old, and realizing that in the day…
flat roofs had two choices… asphalt and pitch…
and a man’s ability was measured by how many skeins
he used on his mop.

David