Riding arena - Sub base

[whatnot]

Constructng an arena - removing thin layer of topsoil to get down to good quality chalk - the arena surface will be wood fibre - the question is: what type of stone to put down in between the chalk and the wood fibre in order to form a good solid base which will take the pounding of horses' hooves and at the same time allow water to drain through. I thought limestone type 1 would be OK, but my aggregates supplier says this will form a seal and prevent percolation of water through. Is he correct? They suggest limestone 40mm will drain well but I am worried this won't be strong and firm enough. Please advise!

[lutonlagerlout]

aren't limestone type 1 and limestone 40 mm the same thing??
sounds ideal to me
LLL

[Dave_L]

I was gonna say the same. Type 1 will be fine IMO.

[Suggers]

Agree with Dave & LLL - we used type1 here, 3/4 years ago - no probs so far - drains well and stays stable - oops no pun intended.....

[lutonlagerlout]

thats terrible suggers
bruce forsyth wants his joke back!
LLL :laugh:

[Mikey_C]

this is out on a limb for DIY'er but I have been told that you can by a Type 1 with reduced fines "for better drainage", this did come from a someone who/uses and orders this material for the construction of sports grounds, as Type one is only a crushed base material (limestone/concrete) and sieve settings I could believe a slight change to the sieve settings could produce Type 1 which has less fines filling the voids after the larger pieces interlocked to give the strength.

Like an orthopedic shoe wearer I am willing to stand corrected.

[very simple simon]

you are not wrong mikey, the big quarrying & civ engineering firm down here gallagher sells a crushed type 1 which has exactly that, less fines. I have seen it used for sites where ground water has been a problem. It meeets the type 1 spec (31.5mm to dust) but has reduced fines, which prevents it going too much like mud

[whatnot]

Thanks all.

Ok, so if less fines produce better drainage, would pure 40mm produce OK strength?

Or do you need Type I (with less fines) for strength and solidity?

[Tony McC]

You can't have a Type 1 with "less fines". The proportion of fines is governed by the grading envelope for Type 1 specification. If you reduce the fines content, it's no longer a Type 1: it's more likely to be a Type 3.

It's akin to saying you can get a diesel with less light aromatic hydrocarbons: you can get a fuel with less light hydrocrabons, but it won't be diesel - it'll probably be petrol! So: you can get an aggregate with less fines, but it won't be a Type 1.

[lutonlagerlout]

found this
which may be of help
LLL