Pier fixing...

[RobertM]

I have just bought some 20mm threaded rod for fixing my pier  (did I go ott on this one ?).   I was thinking 15cm above plus 35cm in the concrete block but I could go to 85cm if need be.  Anyone know roughly how deep I should embed them ?

Many thanks
Robert

[mickw]

Just leave enough above the ground to get a nut and washer on.

The more you bury in the ground/concrete the better and more importantly, the more secure you will feel.

Bottom line - don't cut a bit off and throw it away - Bury whatever you don't need above the ground, spinning a nut on the first couple of threads at the bottom of what you bury will really make is secure.

If you are casting the stud into the concrete, you can support them at the right height/depth poking them through cardboard to match the fixing holes in the pier.

[RobertM]

Thanks Mick,  I'd actually intended to have about 6" above the concrete so I could level it.  Good idea about the nuts spaced out to get better fixing, I'll certainly do that.

I still think 1m (less about 15cm) imbedded is ott but but it saves cutting them and would help to reinforce.

[mickw]

Sorry, I read your measurements as milimetres not centimetres 

Would it be better to fix rigidly at the base and do the levelling at the mount to reduce any flexing ?

[RobertM]

Hmmm, probably is better to fix direct to the concrete - just as long as I get the surface level.  I think there's more likelyhood of the 5' steel pier flexing than anything else (the rods are about 10lbs weight each !).

I'm not too fussed about getting the pier exactly vertical as my mount doesn't need it but it may make life easier if it is.

[Tony G]

If you are concreting the pier, just make sure that the outer casing is constantly vibrated some how, (maybe with one of those facial massagers that women carry around) maybe with a hammer drill or small breaker, as this will stop honeycombing and reduce the air in the concrete and may help with the level on top, when the excess water has been removed.

Tony G

[mickw]

I agree with Tony - A coach bolt in a hammer drill works a treat

[RobertM]

Thanks for the advice.  That's a good point about getting the air out of the concrete, should give my Dad something to do

[Rocket Pooch]

Robert,

But some self leveling concrete, I used it for my pier and its 100% flat, then you don;t have to muck around with too many spacers.

You just mix it up and poor it onto the based and it spreads flat.

Chris

[mickw]

I forgot all about that stuff -

http://www.wickes.co.uk/invt/154441

[RobertM]

Perfect, just what I need.  Thanks lads.

[RobertM]

Have found the expanding filler an excellent damping material in the pier.  £10 of the stuff  80% fills the 8" 5ft tall pier.  I just know someone is going to say 'you shouldn't have done that' for a very good reason !