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We are installing a pole/mast for wireless communication equipment on the roof of our commercial building.

The pole will need to rise 2m above the roofline. Obviously we want the pole to be as securely attached as possible.

This is our current plan of attack:

Buy a 3m length of galvanised pipe and have it extend 1m below the roofline, parallel with a reinforced concrete column (part of the building structure).

Pass the pipe through two attachments, which I'm not familiar with the name of. They are like a pipe clamp with a plate welded to it. One near the top of the 1m overlap with the column and one near the bottom.

Fix each plate to the concrete column in four places.

Attach three guy ropes to the top of the pole, one away from the concrete column and one in each direction perpendicular to that. The guy ropes will be fixed to parts of the building structure and a turnbuckle will be used to tighten them hand-tight.

Does this sound like a secure way to mount the pole and the guy rope ends?

I have heard that epoxy glue-in bolts are more secure than Dynabolts (expansion bolts) and reduce the risk of the concrete cracking. Is this true? Are there any resources I should read to use epoxy glue-in bolts correctly?

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Good plan but don't forget to fully seal the top of the pipe so you don't end up with a water feature in your ceiling –  UNECS Oct 11 '12 at 4:52
    
Your scheme seems doable. For just one meter extension above the top concrete column mounting point it seems a bit overkill to add the three guy lines. It seems like you just need to size the diameter of your pole appropriately. Now if you live in a high wind area and are anticipating putting some type of 2 or 3 meter dish on the pole then that may be another thing again. –  Michael Karas Oct 11 '12 at 4:53
    
It will extend two metres above the top concrete column mounting point (one metre of the pole will be along the column, two metres above it). We will end up mounting several 50cm+ dishes to it. Our area has occasional high wind. –  Jasper Bryant-Greene Oct 11 '12 at 22:52
    
There is another discussion on here regarding the use if epoxy embedded anchors. See here - diy.stackexchange.com/questions/3131/… –  Michael Karas Oct 12 '12 at 15:23

1 Answer 1

You may want to consider one of the various style of commercial bracket assemblies designed to mount antenna masts onto chimneys and concrete columns. Here are some examples:

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The column doesn't project into the air like a chimney, it has brick infill on two sides of it and a room on the third side. I have access to only one face for fixing the mast. These devices look great but appear to require access to all four faces of the column. –  Jasper Bryant-Greene Oct 11 '12 at 22:49
    
If at all possible I would think it beneficial to put more pipe along the column. The farther apart you can put the mounts into the column the more flex of the upper section of the pipe can be absorbed in the attached section. Think if it as a lever. Or think which is better a fence post buried 0.25 meters in the ground versus one buried 1.5 meters. –  Michael Karas Oct 12 '12 at 15:06
    
Given that you plan to attach several 50cm dishes to the top of the mast I agree that the guy wires are a good idea. For wind that comes straight at the dish that size there can be a good amount of force transmitted into the mast. [Sails are pretty effective on boats :-) ] If you could find a way to triangulate your guy wires with 120 degree spacing it would be the best arrangement. –  Michael Karas Oct 12 '12 at 15:14

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