Earl's Build

[Earl]

The Pier arrived today....

So off we go !!!

and straight away Problem number 1 !!!

what dimensions for the concrete would be the minimum, I don't want to move closer to the garage but at the same time don't fancy smashing up the discovered concrete base under the slabs.

Currently i am 19-20 inches deep.

[Seme]

That's a nice looking pier looks very solid that ground looks abit hard.

[Viv]

Nice to see it's arrived - looking forward to seeing it progress

[Earl]

That's a nice looking pier looks very solid that ground looks abit hard.

the ground below it a nice clay which just slices out, really nice to dig, with a hand trowel.

Yes im using a hand trowel,, grr flex hardcore LOL

[Gina]

Yes, I used a hand trowel to dig out my first hole - heavy, hard, clay and stones after a foot down. Top foot was soil and stones.

[martin_h]

You want to make sure your pier footing doesnt touch that concrete base.

[Earl]

How does this look

[Earl]

Well i think im going to attempt to remove around 8 inches of the concrete path.

Has any one done similar? its only 6 inches thick.

[Sp@ce_d]

I'm planning to start building my own obsy soon, there's a lot of info in here if you have a quick search. As Martin said the big thing to remember is an isolation/dampening barrier of the pier footing from the surrounding area. you don't want it bouncing around when people are walking around it! As a rough guide I got the impression the average size of footing used was about a 3'x3' cube of concrete.

[Earl]

I drilled 4 test holes in the concrete tonight to confirm the thickness, it is 6 inches, my bother in law is bringing a cutter over tomorrow to see if its up to the job

[yesyes]

Are you going to have a raised floor in your obs? If yes, you might as well just bolt the pier to that concrete.

[Earl]

Problem is that concrete goes all the way to the public footpath (from what i can tell) so it could be a vibration issue.

[yesyes]

ah, that would be a no no then ..

[Adamski]

6" thick concrete is sufficient to drill in to and use an epoxy resin to fix the bolts in. no more digging involved.

[Astrokev]

Problem is that concrete goes all the way to the public footpath (from what i can tell) so it could be a vibration issue.

Could you cut / chisel a narrow trench to isolate "your bit" from the public path, so as to isolate it from public vibration? A bit of work through 6" but could be done. Is it re-enforced concrete?

[Earl]

Im moving closer to the garage its the simplest option and in reality is only about 8 inches.

Today I have expanded the hole to full width and it is now half depth.

Also I have built the pier template and the box for the concrete to go into

All of that box has to be under ground level.... JOY

[laser_jock99]

Good luck with the digging- hope you don't find anything unexpected like I did!

[Earl]

Good luck with the digging- hope you don't find anything unexpected like I did!

Do tell !

[Astrokev]

Just a thought. Do you need a box to go under ground? I've not built a pier base (not yet anyway) but as far as I'm aware, most folks put the concrete straight into the ground (to get good contact with the surrounding earth for support) and use a box only at the surface to make a neat finish. Even with backflling the earth around the box, I would worry that this won't be that solid and may result in movement of the concrete.

[Earl]

Just a thought. Do you need a box to go under ground? I've not built a pier base (not yet anyway) but as far as I'm aware, most folks put the concrete straight into the ground (to get good contact with the surrounding earth for support) and use a box only at the surface to make a neat finish. Even with backflling the earth around the box, I would worry that this won't be that solid and may result in movement of the concrete.

I need to use the box to make sure it is isolated from the concrete path

Im actually thinking of having 6 inches of it above floor level now as im feeling lazy

[Astrokev]

If the concrete path is only 6" deep, then you only need isolation for the top 6" surely? I'd suggest using a wooden former for the top 6" which you can remove when the 'crete has set, to either leave a gap, or to fill the gap with something softer than wood - polystyrene or the like.

[Gina]

I might be wrong but I thought the idea was to connect the pier to solid ground. As deep as possible to avoid picking up surface vibrations.

[Earl]

I might be wrong but I thought the idea was to connect the pier to solid ground. As deep as possible to avoid picking up surface vibrations.

Yes, my solid ground will be a 34 x 16 x 16 pillar of concrete at least 26 inches down into the ground, the base of the box will also be concreted into place by at least 6 inches of concrete this will be an area around 24x24x6 minus the floor print of the pier.

I was planning on a 2' x 2' x 2' cube but the concrete slab next to it has made that more awkward, in my initial plan i was going to make my pier attach below ground level as it would be easier to hide if i move, im changing my mind on this and ill deal with it later to allow my concrete base to be above ground level

[laser_jock99]

Do tell !

Power cable in bottom of hole.....

[Earl]

Thankfully all i had was a root, which was only as think as a finger so was no problem.

Hole is finished, tube is in place and concrete has be put around it to secure it.

Ill add some snaps later as I now need a rest LOL.

the box is not totally square to the slabs but in not fussed about that it will be hidden under the floor anyway.