Concrete blocks are 8x16, which is 128 square inches, or about 0.9
square feet. The blocks I've weighed are closer to 35 lbs. (they used
to be closer to 40 lbs., so maybe they aren't as "robust" as they used
to be?). Dunno. At any rate, each block is going to be close to 39
lbs. per square foot. On a 3x3 we use at least 4 blocks, but usually
more like 6 blocks. At 6 blocks on a 3x3 non-pen, I get around 23
lbs/square foot.
So it depends on the area of the mount, how many blocks you're using,
and probably where you source your blocks from.
--
bp
<part {dash} 15 {at} SkylineBroadbandService {dot} com>
On 12/18/2014 8:52 AM, Eric Kuhnke via Af wrote:
I don't think a 10'x10' NPRM (100 sq ft) weighs a total of 5000 pounds
with concrete blocks. 50 lbs per square foot? I don't think so...
If you have one of the small 3'x3' non penetrating mounts (9 sq ft)
and put six 25 pound 16" length concrete blocks on it, that's 16.6 lbs
per sq ft.
On Thu, Dec 18, 2014 at 7:48 AM, Jon Langeler via Af <[email protected]
<mailto:[email protected]>> wrote:
Non-pen mounts with block and antennas. Probably closer to 50lbs
per foot.
Anyone know a reasonable PE?
Thanks
Jon Langeler
[email protected] <mailto:[email protected]>
> On Dec 18, 2014, at 9:36 AM, Chuck McCown via Af <[email protected]
<mailto:[email protected]>> wrote:
>
> Many jurisdictions allow 3 pounds per square foot additional
load without additional engineering.
>
> -----Original Message----- From: Jon Langeler via Af
> Sent: Thursday, December 18, 2014 7:09 AM
> To: [email protected] <mailto:[email protected]>
> Subject: [AFMUG] rooftop weight study?
>
> We've been asked to provide a study of rooftop weight allowances
in order to install a bunch of rooftop mounts. Has anyone else had
to do this? Any info or good engineering firms to recommend?
>
> Jon Langeler
> [email protected] <mailto:[email protected]>
