VintageBigBlue.org

 

Re: Pier foundation advice


Dec 13, 2008

 


----------------------------

#40807 Dec 13, 2008

Hi,



I'm in the process of building a pier for my G11, and am after advice on the size of the foundation.. There are several complicating factors which are going to make this an interesting project:



*. The pier itself is going to be quite tall, as the foundation will be ~1m below a wooden deck that the pier will rise through.. That means that I'm probably looking at 2m of pier above ground.



*. I'm going to have to dig the hole from under the deck, which is also going to make getting the concrete in a challenge as well



*. My G11 carries a reasonable load - a 4" and a 6" refractor.



*. I only got permission to insert a pier in the deck if it can double as an umbrella stand for a large cantilever sun umbrella.. I've figured out how I'll attach it to the pier, but am concerned about the leverage it will extert on the foundation



I'm thinking that I'll use a 6" or larger steel pipe as the pier itself, and fill it with concrete - my big question is how big is the foundation going to need to be to support it all, as I only really have one chance to get this right.



The ground is clay if that's any help, and I'm hoping that there is no limitation to how deep I can dig.. I'm thinking that I'll have to go at least 1m, but would be interested in advice from anyone that's done this, and what diameter foundation you have.



Cheers & thanks,

Rod Mckay

Christchurch

New Zealand





Start your day with Yahoo!7 and win a Sony Bravia TV. Enter now au.docs.yahoo.com/homepageset/?p1=other&p2=au&p3=tagline



[Non-text portions of this message have been removed]



----------------------------

#40810 Dec 13, 2008

* I only got permission to insert a pier in the deck if it can double as an umbrella stand for a large cantilever sun umbrella. I've figured out how I'll attach it to the pier, but am concerned about the leverage it will extert on the foundation



Hi Rod,



Same situation here. Mine must double as a stand for a picnik table.



I'm thinking that I'll use a 6" or larger steel pipe as the pier itself, and fill it with concrete - my big question is how big is the foundation going to need to be to support it all, as I only really have one chance to get this right.



Two thoughts here. The rough rule of thumb for a pier is that it be at least the diameter of the scope used. With your two scopes together, that muddles the equasion, but your G-11 may certainly have a larger scope on it in the future. If money is available, I'd make it a 10-inch pier at least. There is no such thing as too big for a telescope mount.



Also, I would avoid filling a pipe pier with concrete. That will only make it ring like a bell when struck by something. Fill the pier with dry coarse sand. That will damp out vibrations better than concrete

The ground is clay if that's any help, and I'm hoping that there is no limitation to how deep I can dig. I'm thinking that I'll have to go at least 1m, but would be interested in advice from anyone that's done this, and what diameter foundation you have.



I am no structural engineer, but I would be comfortable with a 3-foot deep, 3-foot diameter concrete foundation holding the pier.



Robert Reeves +29.484 98.440

reeves10@... San Antonio, Texas

www.robertreeves.com









Recent Activity

a.. 8New Members

b.. 6New Photos

c.. 1New Files

Visit Your Group

Yahoo! News

Fashion News



What's the word on



fashion and style?



Yahoo! Finance

It's Now Personal



Guides, news,



advice & more.



Everyday Wellness

on Yahoo! Groups



Find groups that will



help you stay fit.

.







---------------







No virus found in this incoming message.

Checked by AVG - www.avg.com

Version: 8.0.176 / Virus Database: 270.9.17/1846 - Release Date: 12/12/2008 6:59 PM





[Non-text portions of this message have been removed]



----------------------------

#40813 Dec 13, 2008

It needs to be 3'x3'x3' a cubic yard. concrete is really cheap compared to the amount of money we spend on our equipment. You can't ad just little if its not stable. I've bee in construction for thrity- five years. Do it right the first time, it's cheaper.

Gil



-------------- Original message --------------

From: "Robert Reeves" reeves10@...>





* I only got permission to insert a pier in the deck if it can double as an umbrella stand for a large cantilever sun umbrella. I've figured out how I'll attach it to the pier, but am concerned about the leverage it will extert on the foundation



Hi Rod,



Same situation here. Mine must double as a stand for a picnik table.



I'm thinking that I'll use a 6" or larger steel pipe as the pier itself, and fill it with concrete - my big question is how big is the foundation going to need to be to support it all, as I only really have one chance to get this right.



Two thoughts here. The rough rule of thumb for a pier is that it be at least the diameter of the scope used. With your two scopes together, that muddles the equasion, but your G-11 may certainly have a larger scope on it in the future. If money is available, I'd make it a 10-inch pier at least. There is no such thing as too big for a telescope mount.



Also, I would avoid filling a pipe pier with concrete. That will only make it ring like a bell when struck by something. Fill the pier with dry coarse sand. That will damp out vibrations better than concrete

The ground is clay if that's any help, and I'm hoping that there is no limitation to how deep I can dig. I'm thinking that I'll have to go at least 1m, but would be interested in advice from anyone that's done this, and what diameter foundation you have.



I am no structural engineer, but I would be comfortable with a 3-foot deep, 3-foot diameter concrete foundation holding the pier.



Robert Reeves +29.484 98.440

reeves10@... San Antonio, Texas

www.robertreeves.com



Recent Activity

a.. 8New Members

b.. 6New Photos

c.. 1New Files

Visit Your Group

Yahoo! News

Fashion News



What's the word on



fashion and style?



Yahoo! Finance

It's Now Personal



Guides, news,



advice & more.



Everyday Wellness

on Yahoo! Groups



Find groups that will



help you stay fit.

.





---------------



No virus found in this incoming message.

Checked by AVG - www.avg.com

Version: 8.0.176 / Virus Database: 270.9.17/1846 - Release Date: 12/12/2008 6:59 PM



[Non-text portions of this message have been removed]









[Non-text portions of this message have been removed]







----------------------------

#40815 Dec 13, 2008

Hi,



Here is an example of a tall pier holding a G11 on top



rainerehlert.com/ObsReal14/cons/Este-Oeste-15.jpg



3feet deep in the ground and total 14feet tall until the lower part of

the anchors for the G11s on top



rainerehlert.com/ObsReal14/cons/Este-Oeste-14.jpg



and here the installed G11s



rainerehlert.com/ObsReal14/cons/OReal14-06.jpg



rainerehlert.com/ObsReal14/cons/OReal14-07.jpg



and here the architectural drawings



rainerehlert.com/ObsReal14/cons/ObservatorioReal14a.jpg



regards Rainer







>

>

>

>

> * I only got permission to insert a pier in the deck if it can

double as an umbrella stand for a large cantilever sun umbrella. I've

figured out how I'll attach it to the pier, but am concerned about the

leverage it will extert on the foundation >

> Hi Rod,

>

> Same situation here. Mine must double as a stand for a picnik table.

>

> I'm thinking that I'll use a 6" or larger steel pipe as the pier

itself, and fill it with concrete - my big question is how big is the

foundation going to need to be to support it all, as I only really

have one chance to get this right. >

> Two thoughts here. The rough rule of thumb for a pier is that it

be at least the diameter of the scope used. With your two scopes

together, that muddles the equasion, but your G-11 may certainly have

a larger scope on it in the future. If money is available, I'd make

it a 10-inch pier at least. There is no such thing as too big for a

telescope mount. >

> Also, I would avoid filling a pipe pier with concrete. That will

only make it ring like a bell when struck by something. Fill the pier

with dry coarse sand. That will damp out vibrations better than concrete > The ground is clay if that's any help, and I'm hoping that there

is no limitation to how deep I can dig. I'm thinking that I'll have

to go at least 1m, but would be interested in advice from anyone

that's done this, and what diameter foundation you have. >

> I am no structural engineer, but I would be comfortable with a

3-foot deep, 3-foot diameter concrete foundation holding the pier. >

> Robert Reeves +29.484 98.440

> reeves10@... San Antonio, Texas

> www.robertreeves.com

>

>

>

>

> Recent Activity

> a.. 8New Members

> b.. 6New Photos

> c.. 1New Files

> Visit Your Group

> Yahoo! News

> Fashion News

>

> What's the word on

>

> fashion and style?

>

> Yahoo! Finance

> It's Now Personal

>

> Guides, news,

>

> advice & more.

>

> Everyday Wellness

> on Yahoo! Groups

>

> Find groups that will

>

> help you stay fit.

> .

>

>

>

>

--------------- >

>

>

> No virus found in this incoming message.

> Checked by AVG - www.avg.com

> Version: 8.0.176 / Virus Database: 270.9.17/1846 - Release Date:

12/12/2008 6:59 PM >

>

> [Non-text portions of this message have been removed]

>



----------------------------

#40817 Dec 13, 2008

Thanks Gil & Rainer.



I spent a couple of hours tunneling under the deck this morning and now have a hole that's ~ 400mm x 400mm x 800mm deep.. The idea was to see what the soil is like at that depth, and to make sure I'm not going to run into any pipes, roots, or other surprises.. It was also a bit of an experiment to see how easy it's going to be to dig in a very confined space, and the answer is NOT EASY.. It's hard to dig from a sitting position, and I lost count of the number of times I hit my head.



From what you're saying I'm close to deep enough - just need to make it bigger.. I did the math on the number of 40kg bags of cement I'd need for a 1m3 hole, and the answer is lots!. At ~ 0.02 m3 per 40kg bag that's 50 bags, or 2,000kg of concrete.. I'm thinking I might not go quite that big, but will certainly go bigger than I have currently.



I get a bit of a hard time at home for some of my construction projects, which tend to be over engineered.. Glad to hear that I'm hopefully not going over the top again ;-)



Cheers,

Rod







---------------

From: "Gjanek@..." Gjanek@...>

To: Losmandy_users@yahoogroups.com

Sent: Sunday, 14 December, 2008 1:01:17 PM

Subject: Re: [Losmandy_users] Pier foundation advice





It needs to be 3'x3'x3' a cubic yard. concrete is really cheap compared to the amount of money we spend on our equipment. You can't ad just little if its not stable. I've bee in construction for thrity- five years. Do it right the first time, it's cheaper.

Gil



------------ -- Original message ------------ --

From: "Robert Reeves" reeves10@satx. rr.com>



* I only got permission to insert a pier in the deck if it can double as an umbrella stand for a large cantilever sun umbrella. I've figured out how I'll attach it to the pier, but am concerned about the leverage it will extert on the foundation



Hi Rod,



Same situation here. Mine must double as a stand for a picnik table.



I'm thinking that I'll use a 6" or larger steel pipe as the pier itself, and fill it with concrete - my big question is how big is the foundation going to need to be to support it all, as I only really have one chance to get this right.



Two thoughts here. The rough rule of thumb for a pier is that it be at least the diameter of the scope used. With your two scopes together, that muddles the equasion, but your G-11 may certainly have a larger scope on it in the future. If money is available, I'd make it a 10-inch pier at least. There is no such thing as too big for a telescope mount.



Also, I would avoid filling a pipe pier with concrete. That will only make it ring like a bell when struck by something. Fill the pier with dry coarse sand. That will damp out vibrations better than concrete

The ground is clay if that's any help, and I'm hoping that there is no limitation to how deep I can dig. I'm thinking that I'll have to go at least 1m, but would be interested in advice from anyone that's done this, and what diameter foundation you have.



I am no structural engineer, but I would be comfortable with a 3-foot deep, 3-foot diameter concrete foundation holding the pier.



Robert Reeves +29.484 98.440

reeves10@satx. rr.com San Antonio, Texas

www.robertreeves. com



Recent Activity

a.. 8New Members

b.. 6New Photos

c.. 1New Files

Visit Your Group

Yahoo! News

Fashion News



What's the word on



fashion and style?



Yahoo! Finance

It's Now Personal



Guides, news,



advice & more.



Everyday Wellness

on Yahoo! Groups



Find groups that will



help you stay fit.

.



------------ --------- --------- --------- --------- --------- -



No virus found in this incoming message.

Checked by AVG - www.avg com

Version: 8.0.176 / Virus Database: 270.9.17/1846 - Release Date: 12/12/2008 6:59 PM



[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]









Start your day with Yahoo!7 and win a Sony Bravia TV. Enter now au.docs.yahoo.com/homepageset/?p1=other&p2=au&p3=tagline



[Non-text portions of this message have been removed]







----------------------------

#40820 Dec 13, 2008

I get a bit of a hard time at home for some of my construction projects, which tend to be over engineered. Glad to hear that I'm hopefully not going over the top again ;-)



Cheers,

Rod







There is no such thing as an over engineered telescope mount.



Keep digging!



Robert Reeves +29.484 98.440

reeves10@... San Antonio, Texas

www.robertreeves.com





Recent Activity

a.. 8New Members

b.. 2New Photos

c.. 1New Files

Visit Your Group

Give Back

Yahoo! for Good



Get inspired



by a good cause.



Y! Toolbar

Get it Free!



easy 1-click access



to your groups.



Yahoo! Groups

Start a group



in 3 easy steps.



Connect with others.

.







---------------







No virus found in this incoming message.

Checked by AVG - www.avg.com

Version: 8.0.176 / Virus Database: 270.9.17/1846 - Release Date: 12/12/2008 6:59 PM





[Non-text portions of this message have been removed]



----------------------------

#40823 Dec 13, 2008

Thanks!. Have just spent another hour and a bit under the deck and have got to the point where I think I'll leave it - barring an unexpected fit of enthusiasm during the week or over Xmas... I've made the general hole bigger and a bit deeper, and have bevelled back the sides so that the bottom of the hole is about 50% bigger than the top.. I'm thinking that I'll also make a collar around it above ground, as being below a deck it's not going to be where anyone might trip on it.



To answer Floyd's question - it occasionally freezes where I live in Christchuch, but pretty much only on the surface of the ground, so I won't have the problem you suggest.. I might however have the opposite problem, as during the summer the ground dries out significantly, and the clay can crack.. However given that we're headed into summer in NZ at the moment, and the ground is shaded by the deck and currently still moist, I'm hopeful that I won't have this problem either.



Arrgggghhh!.. Just read the post from Dennis and it looks like I'm in for more digging }:-s



Thanks for the excellent advice everyone.



Cheers,

Rod







---------------

From: Robert Reeves reeves10@...>

To: Losmandy_users@yahoogroups.com

Sent: Sunday, 14 December, 2008 3:00:13 PM

Subject: Re: [Losmandy_users] Pier foundation advice









I get a bit of a hard time at home for some of my construction projects, which tend to be over engineered. Glad to hear that I'm hopefully not going over the top again ;-)



Cheers,

Rod



There is no such thing as an over engineered telescope mount.



Keep digging!



Robert Reeves +29.484 98.440

reeves10@satx. rr.com San Antonio, Texas

www.robertreeves. com



Recent Activity

a.. 8New Members

b.. 2New Photos

c.. 1New Files

Visit Your Group

Give Back

Yahoo! for Good



Get inspired



by a good cause.



Y! Toolbar

Get it Free!



easy 1-click access



to your groups.



Yahoo! Groups

Start a group



in 3 easy steps.



Connect with others.

.





------------ --------- --------- --------- --------- --------- -



No virus found in this incoming message.

Checked by AVG - www.avg com

Version: 8.0.176 / Virus Database: 270.9.17/1846 - Release Date: 12/12/2008 6:59 PM



[Non-text portions of this message have been removed]









Start your day with Yahoo!7 and win a Sony Bravia TV. Enter now au.docs.yahoo.com/homepageset/?p1=other&p2=au&p3=tagline



[Non-text portions of this message have been removed]



----------------------------

#40825 Dec 14, 2008

Hi Rod



In my days of amateur radio, when we were installing winch up masts we

used to make the bottom of the hole bigger than the top (you are doing

this) and also we used to drive old bits of scaffold pole into the

sides at a downward angle, plus a few into the bottom, this will

effectivly increase the foundation area, just make sure to leave as

much as is possible in contact with the concrete, try to use aluminium

poles as these will not corrode.



If memory serves we used to dig a 1m square hole which was for a 60ft

tower.



Regards Badger



s--- In Losmandy_users@yahoogroups.com, Rod Mckay rodnscope@...> wrote: >

> Thanks!.. Have just spent another hour and a bit under the deck and

have got to the point where I think I'll leave it - barring an

unexpected fit of enthusiasm during the week or over Xmas..... I've

made the general hole bigger and a bit deeper, and have bevelled back

the sides so that the bottom of the hole is about 50% bigger than the

top... I'm thinking that I'll also make a collar around it above

ground, as being below a deck it's not going to be where anyone might

trip on it. >

> To answer Floyd's question - it occasionally freezes where I live in

Christchuch, but pretty much only on the surface of the ground, so I

won't have the problem you suggest... I might however have the

opposite problem, as during the summer the ground dries out

significantly, and the clay can crack... However given that we're

headed into summer in NZ at the moment, and the ground is shaded by

the deck and currently still moist, I'm hopeful that I won't have this

problem either. >

> Arrgggghhh!.... Just read the post from Dennis and it looks like I'm

in for more digging }:-s >

> Thanks for the excellent advice everyone.

>

> Cheers,

> Rod

>

>

>

---------------

> From: Robert Reeves reeves10@...>

> To: Losmandy_users@yahoogroups.com

> Sent: Sunday, 14 December, 2008 3:00:13 PM

> Subject: Re: [Losmandy_users] Pier foundation advice

>

>

>

>

> I get a bit of a hard time at home for some of my construction

projects, which tend to be over engineered. Glad to hear that I'm

hopefully not going over the top again ;-) >

> Cheers,

> Rod

>

> There is no such thing as an over engineered telescope mount.

>

> Keep digging!

>

> Robert Reeves +29.484 98.440

> reeves10@satx. rr.com San Antonio, Texas

> www.robertreeves. com

>

> Recent Activity

> a.. 8New Members

> b.. 2New Photos

> c.. 1New Files

> Visit Your Group

> Give Back

> Yahoo! for Good

>

> Get inspired

>

> by a good cause.

>

> Y! Toolbar

> Get it Free!

>

> easy 1-click access

>

> to your groups.

>

> Yahoo! Groups

> Start a group

>

> in 3 easy steps.

>

> Connect with others.

> .

>

>

> ------------ --------- --------- --------- --------- --------- -

>

> No virus found in this incoming message.

> Checked by AVG - www.avg com

> Version: 8.0.176 / Virus Database: 270.9.17/1846 - Release Date:

12/12/2008 6:59 PM >

> [Non-text portions of this message have been removed]

>

>

>

>

> Start your day with Yahoo!7 and win a Sony Bravia TV. Enter

now au.docs.yahoo.com/homepageset/?p1=other&p2=au&p3=tagline >

> [Non-text portions of this message have been removed]

>







Contact Us
This Site's Privacy Policy
Google's privacy policies

S
e
n
i
o
r
T
u
b
e
.
o
r
g