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Posted: Tue Sep 16, 2003 8:38 pm
by steve r
Hi Tony hope you are well and back on the black stuff.
I am reinstating the lawn around the drive and need to mount a lampost.
The lamp is 1200mm high made from cast alloy and has an hexagonal base with 3 10mm holes at 140mm centres.
Thought about using a plastic bucket as a former to cast the concrete, but I am not sure how to set studs or bolts into wet concrete.
Bet you know of an easier way.
Have just had another roll of film developed and amongst the piccies is the construction of my feature circle.
I seem to remember you asking some time ago for circle piccies so if you still want some I can send them up to you.
Regards Steve
Posted: Wed Sep 17, 2003 8:48 am
by danensis
Drill three holes in the base of the bucket (I find the buckets that tile grout come in are quite useful) and bolt the bolts onto the base of the bucket. Then fill the bucket with concrete and vibrate well (leaving it on the motor housing of a diesel mixer is quite a good way!). You don't even need to take the concrete out of the bucket when you've finished, bury the bucket an' all.
Posted: Wed Sep 17, 2003 5:34 pm
by 84-1093879891
Hi Steve,
I'm more or less back to normal - or whatever it is that passes for normal in my life. I'm hoping to get down there to see your driveway on the 25/26th, but I'll cvonfirm that as soon as I know for sure. Still, the pictures are always welcome!
When it comes to casting in-situ concrete with projecting ancor bolts, the simplest way is to dig your hole for the concrete, making sure the anchor block will be big enough to support the post and light fitting. Get a piece of 6mm ply that's roughly the same size as the bas plate and mark the bolt positions on it. Drill through and use a couple of nuts either side to fasten the bolts in place on the ply, so that they correspond to the holes in the base plate of the lamp column, with ample cover into the concrete, and enough of the 'stud' sticking up to allow the base plate to be securely fastened once the concrete has cured.
Mix your concrete (a C20 or C30 equivalent), pour it into the hole, vibrate or tamp to drive out any air pockets or void, and then settle the ply-and-bolts template onto the surface, aligning it as required and checking that it's more or less level. Allow the concrete to cure for at least 5 days before stripping the ply template and fitting the column.
Does the lamp come with anchor bolts or are you going to use threaded rod?
Posted: Wed Sep 17, 2003 9:30 pm
by steve r
Let me know and I'll get the kettle on.
I'll post piccies tomorrow.
The post doesn't have any fittings with it. I did check with the suppliers and they said you have to make your own arrangements.
I still have a lorry load of crap to get rid of, and the top soil I had hasn't gone very far, so I'll be scrounging at the weekend.
Regards
Steve
Posted: Thu Sep 18, 2003 3:55 pm
by 84-1093879891
A length of threaded rod is the cheapest option, and it allows you to 'kink' one end, turning it into a J-bolt for even better anchorage in the concrete.
Could the lorry load of crap not be buried under the topsoil?
Posted: Thu Sep 18, 2003 7:17 pm
by steve r
Would you suggest a length for the stud.
Had a look at some coach bolts today, but the longest length was only 150mm.
The crap is large pieces of concrete that I pulled out to accomodate the kerb to our access track and there isn't enough depth to bury.
A local farmer has promised to pitch up with a trailer on Saturday morning and collect the lot.
Regards
Steve
Posted: Fri Sep 19, 2003 10:34 am
by 84-1093879891
Allow 200-300mm for the stud length into the concrete, but be sure that there is at least 50mm of cover to the studs - ie: there is a minimum of 50mm of concrete between the stud and the world outside.
200mm is fine, with, say, a 50-100mm tail formed by bending the treaded bar through 45º or more, if you're using a 300mm thick anchor block. :)