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Pier Built from Bricks?


kirkster501
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So that I can move my potential new observatory and leave no record of its existence if (when) I move home in a few years I'm thinking of  making a brick pier built on top of a block of concrete that finishes 6" below ground level.  Easy to smash down when house moving and fill with gravel etc into the hole vacated by the pier.

Researched into this and RodgerTheDodger has built one which he discusses in this thread.

http://stargazerslounge.com/topic/152143-brick-pier/

Anyone have any other thoughts about doing this please?

I could render it to make it look the part too.  I already have hundreds of bricks.

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I have a Skywatcher Pillar, which a friend (certified brickie!) "jacked up" on three brick plinths.

I began to wonder why I hadn't asked him to build a brick pier and sold the Skywatcher Pillar. :o

No construction expert, but having seen "errant yoofs" kick down ornamental walls, I sense

it best to go for a four brick "box" structure. Maybe also incorporate some "rebar" thingies?  :p

Attaching it firmly to (below) "ground" might be quite important. But then, I'm just speculating.

Who knows? You might have a "good dinner" before observing... lean a little too heavily!  :D

Edited by Macavity
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My very first pier, built in the late 1950's was made with house bricks, it supported a 5" refractor without problem. I currently have a 8,5" refractor on a pier made from a stack of 18" concrete building blocks cemented as a square using 2 per square, no stability problems with this either.   :smiley: 

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I am planning my first roll top observatory now and the pier is my stumbling block. Do you have to have a template custom made to set into the pier to allow the mount to attach to the pier or can you buy them specific to the mount?

Also, how do you determine the height of the pier? Surely the higher it is the lower to the horizon the scope will reach but this will then affect the height of the walls of the obs!

The brick pier idea sounds the most affordable and least hassle to create/install.

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I am planning my first roll top observatory now and the pier is my stumbling block. Do you have to have a template custom made to set into the pier to allow the mount to attach to the pier or can you buy them specific to the mount?

Also, how do you determine the height of the pier? Surely the higher it is the lower to the horizon the scope will reach but this will then affect the height of the walls of the obs!

The brick pier idea sounds the most affordable and least hassle to create/install.

That is one of the reasons I want to build a brick pier;  If it is the wrong height I can build it a bit higher or carefully knock off the top bricks if it is too high.  My current thinking is to make it the same height above the observatory floor as is my current tripod.

My only concern is if the scope will be able to reach the zenith if set on a brick pier.  I need to do a mock up of this.  I would like to do the concrete pipe pier but it looks to be too permanent.  I want to be able to leave no trace of the pier's existence when i move house.

What brake disks have people used to make the mounting plate for an NEQ6 please?

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Another option would be to bolt together 4 treated wooden fence posts and sink them into a concrete base?

I can't imagine there would be any warping and stability wouldn't be an issue.

Thoughts?

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It seems that, in practice, brick piers are working. However, they don't 'feel' right to me without some rebar running full height down the middle. Bricks and mortar are strong in compression. If, for some reason, the mount is given a push from, say, the north then the north side of the pier will be put into tension and the south into compression. Mortar, my builder friends have always insisted, is not a glue but a bedding medium so it does not resist tension very well. The pier's resitance to tension is only as strong as its weakest brick to mortar surface.

So, while there are successful brick piers out there, this nagging doubt remains in my mind. The whole point of rebar is that it brings strength in tension to concrete which is strong mainly in compression.

Olly

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As much as I'd like to install a steel pier (obviously the most reliable choice) I am having an ongoing battle trying to get approval from my wife. Hurdle one was having an observatory which I have cleared!

Now is the cost, I have a second shed 2m x 3m and am confident that I can convert this, however I am trying to keep the cost down and cannot justify £250- £300 on a pier, so far a concrete pier is winning but I think reinforced posts may also work well?

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It seems that, in practice, brick piers are working. However, they don't 'feel' right to me without some rebar running full height down the middle. Bricks and mortar are strong in compression. If, for some reason, the mount is given a push from, say, the north then the north side of the pier will be put into tension and the south into compression. Mortar, my builder friends have always insisted, is not a glue but a bedding medium so it does not resist tension very well. The pier's resitance to tension is only as strong as its weakest brick to mortar surface.

So, while there are successful brick piers out there, this nagging doubt remains in my mind. The whole point of rebar is that it brings strength in tension to concrete which is strong mainly in compression.

Olly

I would definitely use some rebar.  When it was time to move home I could knock the pier down and hacksaw the rebar below ground  (that i'd set into the concrete block as it were poured).

Also, I have seen some nice bricks for this in B and Q.  The Paved drive edging bricks have the corner rounded off.  Four of these per 20cm gain in height x 15 layers will give a lovely structure!

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It seems that, in practice, brick piers are working. However, they don't 'feel' right to me without some rebar running full height down the middle. Bricks and mortar are strong in compression. If, for some reason, the mount is given a push from, say, the north then the north side of the pier will be put into tension and the south into compression. Mortar, my builder friends have always insisted, is not a glue but a bedding medium so it does not resist tension very well. The pier's resitance to tension is only as strong as its weakest brick to mortar surface.

So, while there are successful brick piers out there, this nagging doubt remains in my mind. The whole point of rebar is that it brings strength in tension to concrete which is strong mainly in compression.

Olly

IMO people over complicate things, if your system is balanced then the only forces are compression, downwards through the pier, and none of our systems are heavy enough to even be noticed by the mortar. There are no torsion forces to worry about, and with any pier, you don't walk near it when an imaging run is on.

Just remember that people happily carry a HEQ into a field and set it up on a tripod to do imaging without worrying that the legs are flexible (way more than concrete or brick/mortar) and resonate beautifully when vibrated :)

I'm on my second brick pier, and it won't be my last :)

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I have seen brick built chimneys with Ariel masts on that defy logic, they have been there may years through assorts on weather and wind but haven't been blown over.....bit of rebar wouldn't hurt though.....

Indeed. You can also customise it precisely to your requirements.  Agreed a pipe filled with concrete is probably better but a bit too permanent for my requirements at present.  Only issue with brick is that the Rebar can only go in the centre of the pier between the criss-crossing layers.  So my plan is to rebar a piece in the block of concrete when I cast it then build around it.  When I get 36 inches off the ground I can then set the four M12 pier head mounting bolts for the adjustment plates and build around these for the final 12 inches.  I'm trying to think how to bend the ends of a M12 threaded bar though!

i think this should work.  All sounds good in theory I concede!!!!  Practice is a another matter!

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if your planning on a cocrete black 6 inches under surface level why not just get a regular steel pier and take it off when you move?

££££££££   and also because most steel piers are "only" 38 - 40 inches or so in height, some of that height will be "wasted" below ground - six inches to quote your example Earl.  Then, by the time the obs floor is installed nigh on a 10" - 12" of the pier's height has been used up, meaning the working height of a commercial steel pier (or others that I have seen) will only be 30 inches above the observatory floor.  This is my thinking, and I could be wrong!

Another thought though.  Could I cast the block of concrete and leave below ground level - six inches or so.  Then install two courses of blue bricks onto which a steel pier could be installed?  Come time to move the bricks can be sledge-hammered off the top of the concrete block and gravel thrown on top of the concrete block?  Anyone installed a steel pier onto a one or two courses of bricks to raise the height?

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IMO people over complicate things, if your system is balanced then the only forces are compression, downwards through the pier, and none of our systems are heavy enough to even be noticed by the mortar. There are no torsion forces to worry about, and with any pier, you don't walk near it when an imaging run is on.

Just remember that people happily carry a HEQ into a field and set it up on a tripod to do imaging without worrying that the legs are flexible (way more than concrete or brick/mortar) and resonate beautifully when vibrated :)

I'm on my second brick pier, and it won't be my last :)

^^This^^

A single row of bricks in a decorative wall can easily be pushed over.

Something like this (from your original post0 would need a fair bit of effort to damage it.

post-11721-0-71674900-1338909282.jpg

As for rebar? Where exactly would you put it in a pier like that?

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Aye, there's the rub? But hey, there are bricks with holes...

(Google search) And seemingly in significant variety too! ;)

It may be possible to get the holes to line up suitably...

Actually, I did drill some 1" holes into *concrete* bricks with

a standard (budget) 1" drill which fits my power drill chuck. :o

Probably not suitable for much repetition, but, at a push.

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Aye, there's the rub? But hey, there are bricks with holes...

(Google search) And seemingly in significant variety too! ;)

It may be possible to get the holes to line up suitably...

Actually, I did drill some 1" holes into *concrete* bricks with

a standard (budget) 1" drill which fits my power drill chuck. :o

Probably not suitable for much repetition, but, at a push.

Absolutely no need to push rebar into the holes in the bricks.  There's plenty of brick structures standing without needing such bodges.

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Zakalwe, is that an inch of concrete at the top of your pier into which the plat mounting bolts are set?  How far vertically down into the brickwork do your plate bolts go please or are they just set into the concrete at the top?

There is no rebar at all on this then and it's just built directly on the concrete block below the ground?  A few more piccies of it please?

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It seems that, in practice, brick piers are working. However, they don't 'feel' right to me without some rebar running full height down the middle. Bricks and mortar are strong in compression. If, for some reason, the mount is given a push from, say, the north then the north side of the pier will be put into tension and the south into compression. Mortar, my builder friends have always insisted, is not a glue but a bedding medium so it does not resist tension very well. The pier's resitance to tension is only as strong as its weakest brick to mortar surface.

So, while there are successful brick piers out there, this nagging doubt remains in my mind. The whole point of rebar is that it brings strength in tension to concrete which is strong mainly in compression.

Olly

I wouldn't bother with reo. think how hard you would push a 300mm x300mm pier to topple it and then apply that to a tripod. the tripod would be in next doors garden (seldom seen)  :). Ok, its not going to be as solid as a steel or concrete pier, but just dont reverse your car into it :D

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Zakalwe, is that an inch of concrete at the top of your pier into which the plat mounting bolts are set?  How far vertically down into the brickwork do your plate bolts go please or are they just set into the concrete at the top?

There is no rebar at all on this then and it's just built directly on the concrete block below the ground?  A few more piccies of it please?

That's RogerTheDodger's pier. You linked to it in your first post in this thread.

I think that it looks like a brilliant design. Solid as a rock and pretty cheap to build, especially when compared to a shop-bought steel pier.

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