Non-Penetrating Peak Roof Mounts

[Stupidfatkid]

I have a metal pole barn with a 22' peak at the top of the roof. I was looking at getting a non-penetrating antenna peak roof mount, specifically the L-com’s HGX-PRM-2. They're not cheap, so I'm curious if anyone has experience with that type of peak roof mount and what their experience has been with it.

 

[dave3825]

What's the wind like during storms in Kansas?

• Operating wind speeds up to 31 mph
• Survival wind speeds up to 62 mph

 

[mmckenna]

What kind of antenna are you planning on mounting to that?

I've used something similar at work, both the peak roof mount as well as a flat roof sled.

From the spec's it is saying 300 pounds of weight on the roof once loaded down with the cinder blocks. Make sure the roof can properly support that.
As Dave said, low wind speed ratings are a concern. What bothers me about that is it does not list a wind load rating (how many square feet of antenna is can handle) at those wind speeds.

They can damage the roof, and we always install them with something between the roof and the sled. Most of ours are flat roof tops, so an extra layer of roof membrane and manufacturer specified pads are used. You'd want to look at what you'd need between the sled and roof to properly protect it.

We always considered those as a 'temporary' mount and prefer to do something more permanent. Since it sounds like what you are doing is not temporary, you'd do yourself a favor at least comparing to some other mounts. For the price of that sled mount, the blocks and the protection to the roof, you might do better with a small (Rohn 25) tower on the ground and braced to your barn.

 

[Stupidfatkid]

For Kansas, the wind gusts aren't too bad where I live. We may get gusts around 40 mph in a good storm, but it's rare. I was thinking of trying to keep the wind load down by using a Comet GP-1/GP-3 style/size antenna and maybe a discone for the second antenna. I did see the mats and would definitely get one. I read where they suggest using two mats for peak roof mounts. I feel the building is pretty solid, so hopefully, weight could be reasonably handled; although 300 lbs is a lot. I was originally looking at putting up a couple of sections of 10' tower, but I can't work out a great spot due to power lines on one side and a retaining wall on the other. Behind the building, there is only about 4' to the fence with a steep grade on the gravel. A good point to try to avoid making it permanent. But I know myself, I'm lazy; once I get it up, it'll be there forever. I can't count how many temporary solutions around the house have become permanent fixes.

 

[mmckenna]

I can't count how many temporary solutions around the house have become permanent fixes.

"There is nothing more permanent than a temporary solution."

I hear you.
I'd look at some other roof peak mounts that give you some actual numbers regarding wind area of the antennas.

I think if it was me, I'd still find a place to mount a tower.

 

[jeepsandradios]

I would just drop a piece of 1 1/4" galvinzed pipe thru the roof just off the peak and use a roof vent seal around it. I've done that on many buildings as well as my house and its held up pretty well. Pipe clams to the inside rafters.

 

[Stupidfatkid]

I'd look at some other roof peak mounts that give you some actual numbers regarding wind area of the antennas.

I wonder if Legal won't allow them to supply wind load numbers? I noticed this line on all their non-penetrating roof mounts: "Note: Ballast data should be determined by a local professional engineer. Adequate ballast material must be determined and provided by others."

 

[Stupidfatkid]

I would just drop a piece of 1 1/4" galvinzed pipe thru the roof just off the peak and use a roof vent seal around it. I've done that on many buildings as well as my house and its held up pretty well. Pipe clams to the inside rafters.

That's what @mancow did through one of the eaves on his house. It works, but I just can't bring myself to drill a hole through a perfectly good roof. That's on me, but I just can't do it.

 

[mmckenna]

I wonder if Legal won't allow them to supply wind load numbers? I noticed this line on all their non-penetrating roof mounts: "Note: Ballast data should be determined by a local professional engineer. Adequate ballast material must be determined and provided by others."

Possible, usually there is wind loading data on this so an engineer can get a general idea of what it'll support.

And I second the 1-1/4" pipe through the roof trick. Less load on the roof and easier to deal with. Put a weather head on the top for an easy way to get the coax inside.

 

[Stupidfatkid]

I would just drop a piece of 1 1/4" galvinzed pipe thru the roof just off the peak and use a roof vent seal around it. I've done that on many buildings as well as my house and its held up pretty well. Pipe clams to the inside rafters.

I know wind load of the antenna(s) you put on the pipe would factor in, but how much pole do you have sticking up from the top side of the roof?

 

[wtp]

I would just drop a piece of 1 1/4" galvinzed pipe thru the roof just off the peak and use a roof vent seal around it. I've done that on many buildings as well as my house and its held up pretty well. Pipe clams to the inside rafters.

jeepsandradios,
can you contact me about something totally different ?

 

[jeepsandradios]

Mine has about 5' out of the roof. 5' inside on the rafters. I used unistrut and unistru pipe clamps then drilled and threaded a 2 hole lug for my ground wire. I have a weather head on it with 3 LMR 400 cables thru it. Those actually work really well. I have mine about 3' down from peak. My DB204 is above the peak as is my yagi for 800

 

[tvengr]

What kind of snowfall do you get? The weight of the sled plus a heavy snow may be too much for your roof to handle.

 

[prcguy]

The weight from a non pen mount is spread out over a large area so the psi is not a big deal and probably much less than you just standing on the roof. There are also different brands of mounts and another one may be cheaper. It sounds like the wind load is going to be very small so just get a good non pen peak roof mount and put your antennas up, you could have been using the antennas all this time.

 

[Stupidfatkid]

What kind of snowfall do you get? The weight of the sled plus a heavy snow may be too much for your roof to handle.

In my area we only average 12.4 inches of annual snowfall a year.

 

[Stupidfatkid]

The weight from a non pen mount is spread out over a large area so the psi is not a big deal and probably much less than you just standing on the roof. There are also different brands of mounts and another one may be cheaper. It sounds like the wind load is going to be very small so just get a good non pen peak roof mount and put your antennas up, you could have been using the antennas all this time.

From the responses on this thread, which I appreciate, I think I might do a combination of suggestions; put a non-penetrating peak roof mount up and put a pipe through the roof with a weather head to run the coax through. That way I can test out both and remove the non-penetrating peak roof mount if it turns out to be an issue.

 

[BinaryMode]

A couple of sandbags on the peak roof mount would work you'd think...

Edit-

Quick search reveals a sandbag can weigh as much as 50 LBS... So 6 of those. LOL!

I don't know. Perhaps just use a regular antenna mount and bolts through the roof. But use sealant and whatnot.

Edit 2-

Make sure you ground. No sharp bends...

 

[Stupidfatkid]

A couple of sandbags on the peak roof mount would work you'd think...

Edit-

Quick search reveals a sandbag can weigh as much as 50 LBS... So 6 of those. LOL!

I don't know. Perhaps just use a regular antenna mount and bolts through the roof. But use sealant and whatnot.

Edit 2-

Make sure you ground. No sharp bends...

I'll probably look into concrete cap blocks. It looks like the 2" x 8" x 16" blocks that Home Depot sells are 13.2 lbs a piece. I'd have to figure up how many fit in the base to get a total weight.