Date: Tue, 13 Dec 2011 12:58:34 -0800
From: Grant Saviers <grants2@pacbell.net>
Subject: Re: [TowerTalk] Grouting a New Tower?
Have the same tower, I am wondering about the benefit of grouting,
especially after taking down a TMM433 that had a lot of rust underneath
the base plate as a result of the grouting. My inspection of street
light standards has been inconclusive 50/50 grout/no grout. Same with
cell towers with nuts under the base plates, mostly no grout.
Besides UST recommending it, why is it an advantage?
Grant KZ1W
On 12/13/2011 11:48 AM, Steve Jones wrote:
> All-
>
> I recently put up a US Tower HDX-589 crank-up. UST recommends grouting the
> the space between the base plate and the top of the foundation block. I
> have purchased the proper non-shrink construction grout and am getting ready
> to do the job. But I'm concerned because I used this stuff to patch my
> house foundation before, and it sets up so quickly I'm not sure how much I
> should mix up at a time.
>
> Any suggestions?
>
> 73,
>
> Steve
> N6SJ
### I already went through that grouting business with my local structural
eng. [ HDX-689]
He sez it's an aesthetic thing....and perhaps will stop small creatures from
getting in below.
The major drawback is..... moisture and water WILL get in there
eventually....and then the
same moisture can't get out ! It's now trapped in there, and will just
accumulate. My eng sez
DON'T install the grout ! Complete waste of time, and adds no additional
support either.
Leave it open, so it can breath.
## I started checking lamp posts and also these 100' tall lamp posts used at
local
sporting facilities. 80% have the grout. I think in these cases, it's more
of a tamper proof
security thing. IE: grout on all sides, so the nuts can't be accessed from
below by vandals.
On top, they will sometimes "double nut" them. I doubled nutted on top, since
I had loads of
excess thread left, and the heavy duty nuts were not too expensive.
## On a similar note, I asked UST how much TQ to put on those nuts. My 12 x
threaded rods
are all 1.125" and the nuts are huge things. 1 13/16" sockets and open end
wrenchs.
UST sez... "snug tight". What the hell does that mean? I lubed all of
mine with marine
grade 'never seize' [ nuts and rods] and initially cranked em up to 90 ft lbs.
Portland bolt tells me you only require aprx 60% as much TQ when threads are
lubed.
Big difference between TQ and 'tightness' . 90 ft lbs lubed is like 150
ft lbs dry.
Same deal on the 18 x transverse smaller 1" bolts, 6 per leg.. that hold the
bottom section
to the base. If u wreck those things, no big deal, they can be replaced. The
12 x embedded
rods can't be replaced, so until I find a better TQ number, I'm gonna leave em
at 90-100 ft lbs.
Later... Jim VE7RF
>
>
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