roll roofing for flat roof - 1/2 lap vs full granular
mark s
existing was 1/2 lap (granulars on 1/2 of the roll). The local stores
couldn't provide me with an answer as to which is better for a
particular situation.
Thanks for the help.
-mark
markm...@yahoo.com
Travis Jordan
Never heard of a "1/2 lap" granulated surface. The granules protect the
cap sheet from UV damage, so you'd need to have granules over the entire
exposed surface. Sounds like the existing roofing was installed wrong?
Modified bitumen roll roofing (cap sheet) is generally 39 3/8" wide and
designed for installation with a 4" or greater lap.
You have a lot of choices to make - not the least of which is what
system you plan to use (SBS cold applied, SBS hot mopped, SBS heat weld,
or APP torch applied). Then you need to decide how many plies (2, 3,
4?), and finally what materials to use for each underlayment layer.
Make sure you use an approved (by the manufacturer) system.
John Willis
scribbled this interesting note:
Try a SBS modified roll roofing product. Lasts far longer and gives
much better results.
Here's one example. There are others.
http://www.tamko.com/com/mcs.htm
--
John Willis
(Remove the Primes before e-mailing me)
Goodman
As already suggested, a SBS Modified. Cold method is ideal for beginners or
above. The roll roofing you are suggesting is 36" wide with a 19" overlap,
leaving 17" exposed. This is an outdated system which lasts typically of 5-7
yrs. Plus thats a lot of cold process adhesive you must apply.
Modified which I've been using is 39" wide with a 4" overlap, cold process
method and there isn't much to applying it. It is very flexible and won't
crack if it gets folded back.
Goodman
"Travis Jordan"wrote in message
> Never heard of a "1/2 lap" granulated surface. The granules protect the
> cap sheet from UV damage, so you'd need to have granules over the entire
> exposed surface. Sounds like the existing roofing was installed wrong?
It is known as a double coverage roll roofing. The granules are exposed for
17". No granules on 19", this is where solid coverage of adhesive goes. An
outdated roofing material which is still being sold.
Travis Jordan
Thanks - that is interesting to know about. Was it designed for a
one-ply installation, or was it used over a base sheet?
Jeff Cochran
wrote:
>mark s wrote:
>> Which is better for replacing roofing on a low pitch roof? Looks like
>> existing was 1/2 lap (granulars on 1/2 of the roll). The local stores
>> couldn't provide me with an answer as to which is better for a
>> particular situation.
>>
>> Thanks for the help.
>>
>> -mark
>> markm...@yahoo.com
>
>Never heard of a "1/2 lap" granulated surface. The granules protect the
>cap sheet from UV damage, so you'd need to have granules over the entire
>exposed surface. Sounds like the existing roofing was installed wrong?
>Modified bitumen roll roofing (cap sheet) is generally 39 3/8" wide and
>designed for installation with a 4" or greater lap.
Double coverage roll roofing (half lap) is popular locally, but on
low-slope roofs, not flat.
Jeff
Goodman
"Travis Jordan" wrote
> > "Travis Jordan"wrote in message
> Thanks - that is interesting to know about. Was it designed for a
> one-ply installation, or was it used over a base sheet?
One ply installation, no base sheet.
mark s
for the info and the website link (very useful, I found a local
dealer). Cold application is definitely the way I plan to do it.
It's only for a small, low sloped area ~ 16' X 15' - I don't want to
have to replace it every 5 years either! thanks again. take care.
-Mark
"Goodman" <not...@yahoo.com> wrote in message news:<gc3Ac.23341$Di3....@bgtnsc05-news.ops.worldnet.att.net>...
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