50' x 85' wood barrel roof advice

resroofer

hi professionals

-we have a 50' x 85' wood barrel roof lots of slope on our shop

-it has about about 1" of existing what looks like coaltar and mop on
which we dont want to remove

-leaning towards single 50' x 85' 45mil sheet of mechanically fastened epdm

-95% of our roofing jobs are residential

what do you guys recommend ?

should we put a separation sheet over existing cap sheets to keep new epdm from contamination from existing asphalt cap sheets?

thanks in advance

English Roofer

A photo would really help!
Cheers
Dave

__________________
'I can resist anything but temptation'- Oscar Wilde
www.drroofing.co.uk

Scott Holloway

Very unlikely that your barrel roof is coal tar. If it is not some form of cold applied system it is more than likely asphalt.

Ed the Roofer

It can't be coal tar, or else it all would have slid downhill.

Type IV asphalt more than likely.

What does the membrane manufacturer recommend in their specifications manual?

__________________
Just Wait A Minute, I Will Be Right Back With A Link For That.
http://www.rightwayroofingcompany.com/ www.rightwayroofingcompany.com
Roof Estimates, Roof Repairs, Roofers, Roof Leak Help, Elgin, Carpentersville, East Dundee, West Dundee, Sleepy Hollow, Algonquin, South Elgin, Huntley, Lake In The Hills, Illinois

4 seasons

I would definately screw down an iso board, or some insulation board. If your roof is what I am picturing in my head, it sounds like a boatload of fun! not really...but work is work

__________________
A to Z Roofing
Wareham, Mass 02571
1-800-781-1816
zach@azroofers.com
Roof Cleaning

Grumpy

Barrell roofs are no problem for single ply. A cover board and epdm would be fine. YOu may also consider an elastomeric restoration, which I prefer for barrell style roofs. FYI there is a lot of scrap in barrell style due to the shape.

__________________
-Grumpy
Chicago Gutters Chicago Roofing

Ansel

Nail base and granulated modified ........

resroofer

what cover board/sheet do you recommend underneth the epdm and how long will 45mil epdm probably last?

what elastomeric do you recommend and how long will it probably last?

Grumpy

EPDM the membrane will last hundreds of years if not more. The seams and details might only last 20 years. Elastomeric is a 10 year when done properly, most people don't do it properly.

As for the cover board, I like fiberboard when people don't want R value. There is a new product I have been wanting to try that is a 1/4" ISO with one surface being trated with a plastic like product. EPS is acceptable if the deck is not wood.

__________________
-Grumpy
Chicago Gutters Chicago Roofing

BornaRoofer

Fiber board is fine iso is better.

If you use one sheet like you said and glue it down it may last longer than you.

If you mechanically attach it and use batten & cover strips it will start leaking sometime after 10-20 due to the buck water laps every 10'.

If you use smaller sheets and fasten in the seams and don't buck water on any laps it wont leak much if at all even when/if the seams do fail due to the slope of the barrel.