Finding roof vent in snow: is there a whip or antenna
DavidLevi
| Posted in General Questions on
After receiving several feet of snow, our roof needed to be shoveled few winters ago.
With the roof vents covered, they where ‘shoveled’ away. This led to an open hole and attic water damage.
>>> Do you know if someone makes a roof vent whip or antenna?
It would need to be non-metal (for lighting), 3-4 feet long (over the snow), with a spring at the base (for wind) that could clip onto an existing bathroom roof vent covers (as the roof vent was replaced) ?
If not are there any inventor, who …?
Thank you for the advise on the stake pipe, but any ideas on the low roof vents???
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Replies
Easy enough to use a pipe flange and a short piece of pipe to make a socket that you could slide a fiberglass driveway marker rod into. No spring that way, but those fiberglass rods have some flexibility so should be ok.
The other thing I can think of is the reflective markers they use on fire hydrants, which is pretty much what you’re looking for.
Don’t worry about metal attracting lightning, it’s not as simple as that. If you are interested, Polyphaser, a company that makes lightning arrestors for commercial systems, publishes an excellent book on the subject called “the grounds”.
Bill
Thanks I like your idea of using fiberglass driveway on the pipe flange or stack (with two hose clamps).
> Any suggestions for the low roof vents - those are the ones that got shoveled off and caused the water damage?
If you’re trying to physically protect those vents and not just locate them, there is a product made to keep falling ice on antenna towers from destroying antennas lower on the tower. The product looks like a step made of metal slats that has a sort of angle bracket to attach to the tower. You could use something like this above the vents as a stop to keep a shovel from contacting the vent.
Be careful using pipe clamps to secure anything to a vent pipe. It’s easy to crush the pipe with those. It would be better to use some strut with pipe straps, or the old “mount a tv mast to a vent pipe” clamps which are still available.
Bill
David,
Are you having trouble with plumbing vent-stacks, or roof vents? I think Bill and Tom are assuming it's a pipe coming through the roof that is being damaged.
Malcolm I wasn't sure either, bit vague and could be taken either way. I just went with his stack (stake) pipe reference. Main stack and other lower roof vents?
Tom,
I don't know much about snow on roofs. Is there a chance an extension could be swept off by deep snow?
Here in MA, the main plumbing vent stack has to be 3" minimum, additional vents have to be 2" minimum so condensation doesn't freeze and block the vent. The stack also has to be a minimum distance up from the bottom edge of the roof where ice dams can form and potentially damage the vent. Further north, they have a 3" minimum. Sliding snow, especially on slate roofs, can cause damage also. I've seen vent stacks 5ft or more in order to meet codes if windows are above and in close proximity to vents coming from lower roofs. Additional supports are needed, not unlike a smoke stack.
"Additional supports are needed, not unlike a smoke stack."
That must look... interesting?
Malcolm, such tall stacks are typically guyed like in this pic from a commercial project I recently finished. If you look closely, there are four guy wires coming off the top of each stack to anchor it from wind forces.
Heavy snow alone won’t usually sweep a vent off a roof. The nice thing about heavy snow is that in comes down gently and builds up over time. The snowfall itself doesn’t usually cause any damage, unless the roof gets overloaded and collapses. What CAN sometimes cause damage is when a big chunk of snow splits off and slides down the roof avalanche-style, and THAT can sometimes shear off things like vent stacks and gutters.
On big broadcast towers, big sheets of ice sometimes break off and come down the side of the tower. The ice sheet can shear off lower antennas, or even kill someone if they’re working around the bottom of the tower. The little metal bridge that brings cables from the tower over to the equipment building is mainly there to protect the cables from falling sheets of ice. Under that “ice bridge” is also the safest place to stand if you’re around a broadcast tower in winter.
Bill
Add a coupling and add a piece of pipe to extend the vent. Minimum height is usually 18 in but you can go higher.