[NLRS] Tower installation detail question

[Arliss]

John,

I have a used crank-up tower that is waiting for warm weather to 
go up, but hadn't heard of the use of grout as you described, so 
I did some investigating.

A search of the TowerTalk reflector archives:
http://lists.contesting.com/archives//html/Towertalk/
under "base grout" revealed several discussions of this topic. 
Here's the executive summary:

Grout comes in several different types. What you reportedly want 
is non-metallic, non-shrink cementitious construction grout for 
outdoor use. Sakrete, Sika, Quickrete and Master Builders are 
companies that make the stuff. Depending on your location, I 
gather that it may or may not be available at local big box stores.

The reason for using the grout is to protect the bolts from 
exposure to water and any material that might collect between the 
base plate and the concrete and foster rust formation. It may 
also provide some structural support and also would keep the nuts 
under the base plate from moving. That being said, there was not 
unanimous support for using the grout, with some contributors 
expressing concern that the grout can trap water next to the base 
bolts and prevents inspection of the bolts in the future.

My thought is that I'd do what the manufacturer specified. To 
quote a PE that commented on the subject on TowerTalk:

Look in your yellow pages under concrete suppliers to find a source.

I normally specify "Masterflow 928" by MasterBuilders or equal. 
Sika chemical is another manufacturer. What you want is a 
non-metallic, non-shrink pre-package grout. Follow the 
manufactures directions and you should be ok. Non-metallic 
doesn't stain as it weathers.

Regards

Hank Lonberg, P.E.,S.E. / KR7X
Lonberg Design Group, Ltd.



Hope this helps.

73, Arliss  W7XU




http://lists.contesting.com/archives//html/Towertalk/

On 2/5/2017 4:58 PM, John Toscano wrote:
>
>
> Looking for an opinion on my tower installation...
>
> I just installed a US Towers HDX538 tilt-over crank-up tower. There is a
> T-shaped metal plate with three humongous bolts that are embedded into the
> concrete foundation and hold the plate an inch or two above the top of the
> concrete foundation. The bolts each have one nut below the plate and two
> nuts threaded onto them above the plate. Before the tower was attached to
> the plate, I did my best to level the plate by adjusting the nuts below the
> plate and tightening the nuts above the plate. After the tower was
> installed onto the plate, fastened with a total of 9 nuts and bolts, and
> cranked into the upright position, I re-checked the level against the tower
> itself instead of against the plate. The tower was very slightly out of
> perfectly vertical alignment, so I adjusted the nuts one more time to get
> it as close to perfectly vertical as I can with my level.
>
> According to the manufacturer's installation instructions, once the tower
> is leveled, the installer is supposed to fill in the space between the
> bottom of the plate and the top of the concrete foundation with "grout",
> although the description of the consistency of the grouting material sounds
> more like more concrete. Anyway, I mentioned this to one of the hams at the
> Roadrunners Microwave Group yesterday and he asked, "why bother?". My only
> response was, (a) because the installation instructions say so, and (b) to
> prevent any future change from the current (level) setting.
>
> What do y'all think about this? Should I fill in the space with "grout" and
> thereby permanently set the position of the nuts underneath the plate, or
> should I leave the space open so it would be possible to make future
> adjustments?
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