Pier and Pier Base Construction

[Davey-T]

1 minute ago, souls33k3r said:

The one on the patio, that's the one that carries your 10 micron if i'm not mistaken correct?

That's the one, the myth about needing a square meter of concrete seems to have originated on CN probably due to the myriad soil conditions in the USA and the fact that your average American wouldn't even think of digging a hole or mixing concrete by hand 

As long as you're not going to dance around the pier while you're imaging there is no problem in fact many folk image quite happily using a tripod, the pier just makes a permanent setup so is more convenient  and if PA should move over time it's easily corrected.

ATB

Dave

[Bukko]

14 minutes ago, souls33k3r said:

I will agree with you on that mate but the reason why i mentioned the word Muslim is because he's one of the good eggs, like me we don't drink so Biryani will have to do

I have yet to meet a bad Muslim !!

Friendly, helpful and their whole world revolves around thier families.

I am sure you will get the help you need.

Gordon.

[old_eyes]

Haven't dug my hole yet (scheduled for later this week), but basing my thinking on instructions for Altair Astro pier https://www.altairastro.com/public/pier/Altair_Astro_8_Adjustable_Steel_Pier_Installation_Instructions_2014.pdf.

50 x 50 x 90 - rough dimensions.

A number of experts have commented that we over-engineer our pier bases driven by practice in the US when you need to make sure you get below the frost line.

A one-quarter cubic metre concrete block should be sound.

[souls33k3r]

11 minutes ago, Gina said:

As I recall I made my base about 27" cube with concrete pier on top all poured in one go (a whole day) with plenty of rebar.  Four bent pieces of 16mm threaded rod about 3ft long were tied to rebar and held at the top with a piece of wood with 4 holes in.  The pier was (OK still is) about 10" wide at the base and 7" at the top circular.  It's solid as a rock, has an EQ8 on it and has had two 8" x 3ft telescopes on it at one time for a dual rig.

Blimey! that's some serious pier you've got Gina. Like you said i think 75cm one would be plenty to see me through this house at least.

7 minutes ago, Davey-T said:

That's the one, the myth about needing a square meter of concrete seems to have originated on CN probably due to the myriad soil conditions in the USA and the fact that your average American wouldn't even think of digging a hole or mixing concrete by hand 

As long as you're not going to dance around the pier while you're imaging there is no problem in fact many folk image quite happily using a tripod, the pier just makes a permanent setup so is more convenient  and if PA should move over time it's easily corrected.

ATB

Dave

Yeah i did always wonder where the whole meter cube thing came from but then saw everyone doing it so thought it's the gold standard. 

But like you said, as long as i don't go dancing around the pier, it should be fine but then i will be about 70 feet away from it when imaging from the comfort of my sofa

7 minutes ago, Bukko said:

I have yet to meet a bad Muslim !!

Friendly, helpful and their whole world revolves around thier families.

I am sure you will get the help you need.

Gordon.

Cheers mate, most of us are alright people but like you said our whole world revolves around our families

3 minutes ago, old_eyes said:

Haven't dug my hole yet (scheduled for later this week), but basing my thinking on instructions for Altair Astro pier https://www.altairastro.com/public/pier/Altair_Astro_8_Adjustable_Steel_Pier_Installation_Instructions_2014.pdf.

50 x 50 x 90 - rough dimensions.

A number of experts have commented that we over-engineer our pier bases driven by practice in the US when you need to make sure you get below the frost line.

A one-quarter cubic metre concrete block should be sound.

Grand of a share mate. Will surely have it safe and read through once more just before i start to dig. Because i don't work on the weekends, that's the only time i can do this so will do.

[DaveS]

I don't have a sunken block, the pier is bolted down onto a 1.5 m x 2.0 m platform that varies between 0.5 and 0.6 m (To level the top). By my calculations that's about 1.5 cubic metres of concrete. At a density of 2200 Kg / m^3, that comes in at a bit over 3 tonnes. (See the end of my "first thoughts" thread.

Don't think that's going to move much.

[souls33k3r]

6 minutes ago, DaveS said:

I don't have a sunken block, the pier is bolted down onto a 1.5 m x 2.0 m platform that varies between 0.5 and 0.6 m (To level the top). By my calculations that's about 1.5 cubic metres of concrete. At a density of 2200 Kg / m^3, that comes in at a bit over 3 tonnes. (See the end of my "first thoughts" thread.

Don't think that's going to move much.

blimey ... that's a lot of concrete. 

If i go for what John has done which is 75cm in all areas, that comes to 0.4218 m3 ... now i know that whether i go for 75cm or  the 2feet version, it will be either between 0.3 - 0.4 m3 ... i'm very naive on this subject so should i look to keep a 1:4? I was looking at one of these bad boys. https://www.wickes.co.uk/Tarmac-Ballast---Jumbo-Bag/p/131896 . Now this is where my inexperience comes in to play. I have no idea if this is all that i'll need for what i want to achieve? 

[StarDodger]

57 minutes ago, Gina said:

75cm should see you well prepared for any future upgrades.

75cm cube of concrete, is a hefty lump, overkill really...and good luck with digging and if you are mixing by hand... 😮😅😅

[StarDodger]

35 minutes ago, souls33k3r said:

blimey ... that's a lot of concrete. 

If i go for what John has done which is 75cm in all areas, that comes to 0.4218 m3 ... now i know that whether i go for 75cm or  the 2feet version, it will be either between 0.3 - 0.4 m3 ... i'm very naive on this subject so should i look to keep a 1:4? I was looking at one of these bad boys. https://www.wickes.co.uk/Tarmac-Ballast---Jumbo-Bag/p/131896 . Now this is where my inexperience comes in to play. I have no idea if this is all that i'll need for what i want to achieve? 

If you are digging the hole 75cm square and 75cm deep, then that is 0.75m3 of concrete, where do your figures come from...I think you are way out...

[Bukko]

4 minutes ago, StarDodger said:

If you are digging the hole 75cm square and 75cm deep, then that is 0.75m3 of concrete, where do your figures come from...I think you are way out...

0.75x0.75x0.75 is 0.4218 m3

Still overkill and is about the dimensions I did for my ME2 and 16" ODK...

[Gina]

Certainly bigger and heavier than mine and mine was big enough!!

[teoria_del_big_bang]

1 hour ago, souls33k3r said:

blimey ... that's a lot of concrete. 

If i go for what John has done which is 75cm in all areas, that comes to 0.4218 m3 ... now i know that whether i go for 75cm or  the 2feet version, it will be either between 0.3 - 0.4 m3 ... i'm very naive on this subject so should i look to keep a 1:4? I was looking at one of these bad boys. https://www.wickes.co.uk/Tarmac-Ballast---Jumbo-Bag/p/131896 . Now this is where my inexperience comes in to play. I have no idea if this is all that i'll need for what i want to achieve? 

I am not a professional builder but have done plenty of building in the garden and so far everything is still standing.  I would use a 3:2:1 mix

3 parts aggregrate , 2 parts coarse sand and 1 Portland Cement

You can use the calculator here:-

Concrete Mix Calculator

I am assuming the Wickes jumbo bag is the same size as what is often called tonne bags available from most builders merchants. Which is a bit misleading as I think they are generally 800Kg and not a metric tonne.

So you need 6 bags of cement (25Kg), 11 bags sharp sand (usually in 25 or 30 Kg bags) not soft sand as used in mortar, and 21 bags of aggregate (25 or 30 Kg).

The jumbo bag of ballast is actually both concreting sand or sharp sand AND aggregate mixed in the right ratio and is usually much cheaper than buying in seperate 25 Kg bags. So this replaces the sand & aggregate and just needs cement and water adding.

So 1 jumbo bag of Ballast will be a bit more than the 0.7 tonnes you need + 6 bags of cement would suffice and will be the cheapest way I would think. I might be tempted to get 7 bags of cement just in case you get the quantities a bit out as you do not want to run out of cement before the foundation is done  as it should be poured all in one go ( can be several mixes pored one after each other). Personally I would be tempted to put some rebar in as well.

Steve

Edited June 24, 2019 by teoria_del_big_bang

[souls33k3r]

2 hours ago, Bukko said:

0.75x0.75x0.75 is 0.4218 m3

Still overkill and is about the dimensions I did for my ME2 and 16" ODK...

Really? Wow. If you went for the same dimension for yours then I guess I'd be alright with a bit smaller size. I'll start marking the location over the weekend of it I get a chance to come back home slightly early and see how big the hole looks. 

1 hour ago, teoria_del_big_bang said:

I am not a professional builder but have done plenty of building in the garden and so far everything is still standing.  I would use a 3:2:1 mix

3 parts aggregrate , 2 parts coarse sand and 1 Portland Cement

You can use the calculator here:-

Concrete Mix Calculator

I am assuming the Wickes jumbo bag is the same size as what is often called tonne bags available from most builders merchants. Which is a bit misleading as I think they are generally 800Kg and not a metric tonne.

So you need 6 bags of cement (25Kg), 11 bags sharp sand (usually in 25 or 30 Kg bags) not soft sand as used in mortar, and 21 bags of aggregate (25 or 30 Kg).

The jumbo bag of ballast is actually both concreting sand or sharp sand AND aggregate mixed in the right ratio and is usually much cheaper than buying in seperate 25 Kg bags. So this replaces the sand & aggregate and just needs cement and water adding.

So 1 jumbo bag of Ballast will be a bit more than the 0.7 tonnes you need + 6 bags of cement would suffice and will be the cheapest way I would think. I might be tempted to get 7 bags of cement just in case you get the quantities a bit out as you do not want to run out of cement before the foundation is done  as it should be poured all in one go ( can be several mixes pored one after each other). Personally I would be tempted to put some rebar in as well.

Steve

That's super super helpful Steve. I wasn't too sure what that jumbo bag contains really so now I know what it does. Thanks to you

So ill try and look in to getting one of those jumbo bags and 6-7 bags of cement. 

Now what to do with the left over... Not that I'm looking to build anything after this, can this stuff be used else where in the garden? Any ideas? 

[teoria_del_big_bang]

If there is only 800Kg then you will not have  lot left over as you need 710 KG. If you need to use all up then you could either just make it a tad bigger with the extra bag of cement or just dig the hole a bit deeper and line the bottom of the hole with some dry ballast (around 1/8 of the bag).

Maybe just check with wickes what the weight of the bag is.

Steve

[souls33k3r]

13 minutes ago, teoria_del_big_bang said:

If there is only 800Kg then you will not have  lot left over as you need 710 KG. If you need to use all up then you could either just make it a tad bigger with the extra bag of cement or just dig the hole a bit deeper and line the bottom of the hole with some dry ballast (around 1/8 of the bag).

Maybe just check with wickes what the weight of the bag is.

Steve

Will do mate. Cheers for that

[Jkulin]

Ahmed, be prepared to regularly have to do a PA....why?

Because if I bang my head and cut it one more time in the dark on the CW Bar, then I swear I am going to take a circular saw to the d@mn thing!🤬🙄

[Ibbo!]

17 minutes ago, Jkulin said:

Ahmed, be prepared to regularly have to do a PA....why?

Because if I bang my head and cut it one more time in the dark on the CW Bar, then I swear I am going to take a circular saw to the d@mn thing!🤬🙄

You want one of these

 

 

[Shelster1973]

The world is a weird and strange place.

I spent the majority of yesterday researching this exact same thing, so am going to blatantly jump in on this one and use all the advice given so far.

For me, I will be getting the Altair Astro pier and bolting it down, so am following their advice and going for a hole 450 x 450 x 750.  I contacted a local concrete firm for a quote for some ready mixed and they said that they did not do such a small amount.  The minimum they can mix and deliver is 0.5m3.  Yes I can make the hole slightly larger to accommodate (well, twice as big really), but am not happy paying the £171 they have just quoted me.  Will be doing a self mix.

My question (said I was jumping in 😆) how do you create the shuttering around the top of the hole?  I am looking to have the top part squared off and sitting above the level of the lawn.

[souls33k3r]

8 hours ago, Jkulin said:

Ahmed, be prepared to regularly have to do a PA....why?

Because if I bang my head and cut it one more time in the dark on the CW Bar, then I swear I am going to take a circular saw to the d@mn thing!🤬🙄

Sorry John I know I shouldn't laugh but thay just made me laugh so hard because I just imagined you banging your head in to the CW shaft and swearing in the middle of the night with your neighbours looking through their window wondering what has gotten in to John  😂 not that I've ever done it myself but I guess with my height, the only thing you really bang your head in to is the top frame of the doors 😛

13 minutes ago, Shelster1973 said:

The world is a weird and strange place.

I spent the majority of yesterday researching this exact same thing, so am going to blatantly jump in on this one and use all the advice given so far.

For me, I will be getting the Altair Astro pier and bolting it down, so am following their advice and going for a hole 450 x 450 x 750.  I contacted a local concrete firm for a quote for some ready mixed and they said that they did not do such a small amount.  The minimum they can mix and deliver is 0.5m3.  Yes I can make the hole slightly larger to accommodate (well, twice as big really), but am not happy paying the £171 they have just quoted me.  Will be doing a self mix.

My question (said I was jumping in 😆) how do you create the shuttering around the top of the hole?  I am looking to have the top part squared off and sitting above the level of the lawn.

Eek!!! That's just silly price quoted. It will work out so much cheaper if you do it yourself mate. I'm not sure if I can answer your question mate but that's only because I don't really understand what you mean but I will lean on somebody else so that I can then figure out in my head later

I don't mind you jumping in mate. 

By the way, what are you thinking of hanging from the pier? 

[Shelster1973]

Yeah, that was a ridiculous price.  Have been looking around this morning and reckon I am looking at around £50 to do it myself.  Am also going to do the random rebar hammered in trick too to give it some support and also anchor the block too.  Will ask around in work and see if anyone has a mixer I can borrow off them too.

Probably should have explained the question a wee bit better too.  Am just looking for a way to contain the concrete that comes out of the ground.  From looking this morning (busy day in work) I can simply screw together some pieces of wood to create a box and then hold that in place with some heavy weights on each side until the concrete has cured.  Will then just lift off and give me the look I am after.

[Shelster1973]

Oh yeah, gear on the pier (poetry there) will be what is in my sig.  EQ6R-Pro mount, ED72 scope, guide scope and camera, CCD, filter wheel and filters plus primalucie auto focuser and a USB hub.  Scope will eventually be an Esprit 80, but have more pressing things to buy before that.

[souls33k3r]

54 minutes ago, Shelster1973 said:

Yeah, that was a ridiculous price.  Have been looking around this morning and reckon I am looking at around £50 to do it myself.  Am also going to do the random rebar hammered in trick too to give it some support and also anchor the block too.  Will ask around in work and see if anyone has a mixer I can borrow off them too.

If you're like me and will be using it for one time only then borrowing it will be a sound decision otherwise you can always hire them for cheap for a day. 

55 minutes ago, Shelster1973 said:

Probably should have explained the question a wee bit better too.  Am just looking for a way to contain the concrete that comes out of the ground.  From looking this morning (busy day in work) I can simply screw together some pieces of wood to create a box and then hold that in place with some heavy weights on each side until the concrete has cured.  Will then just lift off and give me the look I am after.

Ah this makes sense. What i was thinking of doing is pour the concrete in the hole and then leave about an inch or two before the whole gets filled up. I might be wrong but this is what i had in mind

23 minutes ago, Shelster1973 said:

Oh yeah, gear on the pier (poetry there) will be what is in my sig.  EQ6R-Pro mount, ED72 scope, guide scope and camera, CCD, filter wheel and filters plus primalucie auto focuser and a USB hub.  Scope will eventually be an Esprit 80, but have more pressing things to buy before that.

Oh i so apologise mate, i was seeing this post on my phone so couldn't see your gear in the signature

[Jkulin]

1 hour ago, Shelster1973 said:

Probably should have explained the question a wee bit better too.  Am just looking for a way to contain the concrete that comes out of the ground.  From looking this morning (busy day in work) I can simply screw together some pieces of wood to create a box and then hold that in place with some heavy weights on each side until the concrete has cured.  Will then just lift off and give me the look I am after.

Yes, that is what I did, I used formica boards screwed together and coated in Grease so they pulled away nicely, I kept the top of the block level with the ground so that I could still mow the lawn easily and didn't trip up in the dark

[souls33k3r]

9 minutes ago, Jkulin said:

Yes, that is what I did, I used formica boards screwed together and coated in Grease so they pulled away nicely, I kept the top of the block level with the ground so that I could still mow the lawn easily and didn't trip up in the dark

Great idea John. Thanks for sharing.

[Swoop1]

5 hours ago, Shelster1973 said:

Probably should have explained the question a wee bit better too.  Am just looking for a way to contain the concrete that comes out of the ground.  From looking this morning (busy day in work) I can simply screw together some pieces of wood to create a box and then hold that in place with some heavy weights on each side until the concrete has cured.  Will then just lift off and give me the look I am after.

I concur. Fabricate a bottomless box the dimensions you want the base to be above the surface and secure in place. I have seen it done with pegs fixed to the outside of the box and driven into the ground to keep it in place. When pouring the concrete, do so so that is level with the top of the box then use a trowel or plasterers float to smooth the surface to give a nice finish. If the base is the same dimensons as the bottom of the pier you are going to mount and you intend to use adhesive/ mortar etc, consider roughing the surface to give a good key for the adhesive.

Don't forget to apply a release agent to the inner surface of the box as failure to do so can cause the concrete to stick to the former.

[Shelster1973]

Cheers Swoop1, that's my plan.

Was initially unsure as how to secure the box in place, but seeing the use of old flag stones has helped.  Will more than likely go for pegs to hold it down and don't have anything else really.  Will have a look around and see if I have any random formica boards anywhere and use those for the form, with a liberal smearing of oil on them.  Am not hugely worried about the final look, tbh as will eventually be putting decking around the area, just want it proud of the soil level so as to not have any pooling of water around the base.  Smooth will be ok too as am planning on bolting the pier down.  Will use drill and resin in some threaded bar later on, as do not have the pier atm, so am happy to just create the base / plinth for now