Heating cables in downspout on flat modified bitumen roof?


#1

I live in a townhome development with a flat modified bitumen roof (in the Chicago area). The condo association is considering whether to install heating cables in the downspouts and gutters to prevent ice dams. I have read contrasting info on the efficacy of the cables on various websites though everything I read was regarding sloped roofs with shingles. Can any of you share your opinion or link to a website that discusses the use of heating cables on flat roofs?

Also, I have pics of my roof below. Unfortunately, mine is the one at the lower elevation, which I fear is a disaster waiting to happen. In the last ice and snow storm [pictured below], my neighbor’s roof at the higher elevation was almost clear of any snow and ice, while mine was covered in snow and ice, especially at the downspout and the junction between our roofs. From what I understand about ice dams on sloped roofs, water can infiltrate an intact roof b/c it can get under the shingles. How would this work on a flat roof? Can water get underneath the membrane if it is intact? In regard to the area where my roof meets my neighbor’s, is there anything I need to do, keep my eye on, or worry about, in particular?

I appreciate any advice you may have. Thank you :slight_smile:




#2

leave them in the downspouts.do NOT put them on the roof!!!they will leave blemishes which will cause trouble down the road.your roof looks to be in pretty good shape.so stop worrying. water can not get under this system cause its melted together.if you have a problem come back to this site and ill hook you up with some good guys.


#3

thanks for your reply, roofboss! :slight_smile:

Do you think putting heater cables in the scupper box and gutter is a good idea? I’m not sure how they would be installed because the electrical outlet is about 15 ft from the scupper box, and it seems inevitable that some of the heater cable will end up on the roof.

That’s good to know! So there’s no problem with having my roof one foot lower than my neighbor’s, causing his roof to drain onto mine? So, am I understanding this correctly: ice is not necessarily a problem for modified bitumen flat roofs the way that ice dams can be a problem for sloped roofs with shingles?

Also, I will PM you too. :slight_smile:


#4

Hi,

Shingle roofs shed water. They are not waterproof.

Flat roofs need to be water tight.

You have nothing to worry about.


#5

[quote=“Lefty”]Hi,

Shingle roofs shed water. They are not waterproof.

Flat roofs need to be water tight.

You have nothing to worry about.[/quote]

And that is why low-sloped roofers believe they are better than shingle roofers. :stuck_out_tongue:


#6

they arent??? :smiley:


#7

When I was roofing, I always thought we were better. Afterall, I could put on a shingle, but most shinglers couldn’t put on a proper built-up roof. :smiley:


#8

the flatter the roof gets, the more difficult it becomes.

the roof looks good except arount the scupper holes.
in the roofers defence, that area is extremely hard
to do and make look good,
if your having water enter under those holes
you may want to have your roofer double check
torch work.

gweedo


#9

I agree with that to a certain extent.
However, I did work for an old flat roofer that didn’t have a clue as to efficiently applying a shingle roof.
I showed him though… :smiley:

Following that line of reasoning, a roofer that can do both well is the best roofer. :smiley:

I honestly don’t see how a residential roofer can survive if they don’t know how to apply a flat roof.
Houses have them too.


#10

can you set rolls or mop a 5 ply pitch job?


#11

Yes I can, I used to be very good at it.
Can you sling a mop without hitting me in the face?


#12

yep. a double scaaner too!!!


#13

thats a five pound mop for those who were guessing


#14

Slinging a hot mop gives you tremendous upper body strength.
It is very hard work.
BUR’s are almost nonexistent in my area.
I can’t remember ever smelling a kettle around here.

Most guys don’t realize that the lines on the felt are ply lines…


#15

[quote=“gweedo”]
the roof looks good except arount the scupper holes.
in the roofers defence, that area is extremely hard
to do and make look good,
if your having water enter under those holes
you may want to have your roofer double check
torch work.[/quote]

Hi gweedo. Thanks for your reply. I just had the scupper area patched over the summer. Can you please explain what isn’t “right” about that area? I have no idea what looks good, and what does not.


#16

How are you at setting the rolls by the back line, and kick-rolling? Do you know enough to kick the rolls in the center, because kicking them off center causes them to curve? Just askin’?


#17

Hi Axiom,

They can not let the smell come out of the kettle. Does not mean it is not being used.

Miss the smell. Always knew as a kid when spring was here. You could smell the kettles.


#18

I don’t miss bringing the smell home with me.

I don’t miss putting my boots in the freezer in order to clean them off either.

It has been a long time since I worked with hot.

I don’t miss it at all.


#19

[quote=“gweedo”]the flatter the roof gets, the more difficult it becomes.

the roof looks good except arount the scupper holes.
in the roofers defence, that area is extremely hard
to do and make look good,
if your having water enter under those holes
you may want to have your roofer double check
torch work.

gweedo[/quote]

Hey gweedo,

Did you happen to notice on the last picture that the change in roof elevation isn’t really base flashed? Who ever installed the roof used the roofing membrane like as base flashing for the change in plane. Also, is doesn’t look like the wall flashings extend far enough onto the roof past the toe of the cant strip, but that is hard to say for sure from the photos.


#20

I think what gweedo meant about the ugly looking scuppers is that this is often a very difficult spot to get looking pretty (especially when doing a torch application vs. other methods). Torch is by nature a bit of a sloppy application…

As for what Cerberus was saying - if you look @ the 3rd photo, you’ll see vertically applied lines & the bottom of them look to stop a bit short & could probably have been better served to lay further onto the roof deck or higher up the wall so that there is more of a true “bathrub” effect & the roof panels (sheets, laps, whatever) go futher up the walls.

A “cant strip” is triangular shaped strip of wood that lays into a 90 degree joint, i.e. wall to roof. The purpose of this is to eliminate an air void & allow the product to more easily transition the corner. Roofing materiel doesn’t make a 90 degree without cracking, so a series of 45’s will more easily turn the corner & go vertical.