How to cast apex coping stones in situ.

[mart]

I have this 9” wall that I want to top off with some sort of coping stones. Originally I had thought about cutting some 24x18 paving flags down the middle (to end up with pieces of 24x9), but the end result would be a bit plain looking.

I came up with the idea of fixing some rough sawn timber to either side of the wall, protruding about 2” above the wall to pour concrete in (I have an electric mixer and loads of aggregate). I fancy an apex shape finish along the top of the cast. (Maybe throw a bit of dye in the mix too). The problem is, I cannot work-out how to do. it. For sure, I could fasten some side pieces of timber on top to form the apex. But, even with 2” “pour holes” every couple of feet, I have doubts that the mix would flow evenly enough.

Anyone done this or got any ideas?

 

[Welderpaul]

Make a mould, cast them upside down, then bed them on top of the wall. Lot quicker in the long run and will be a better job.

 

[Tigman]

Make a mould from ply to the shape and size and pour in the conkers vibrate a bit and leave to dry use mould oil and they will come out easier done that before worked a treet ! upside down that is ! no pour holes !

 

[mike os]

as above

 

[Tigman]

you beat me to it !

 

[mike os]

better yet just go and buy them...

 

[Tigman]

there is that method !

 

[mike os]

this time o9f year they need to be in a mould for at least a week, then another week stacked curing

 

[Pete.]

If they overhang the edge of the wall, cast a drip groove in the underside to allow rain to drip off without soaking the brickwork. All you need is to tap a round bar into the concrete before it cures to make a half-round groove shape.

 

[clift_d]

Go and buy them. The time, money and effort that you'll expend to try and make them is not worth it.

 

[Pete.]

True dat, plus you still won't have the quality of finish.

 

[cumbriasteve]

I made some many years ago with my own mould, they came out looking good but over time were not on par with the bought items, I suspect the bought one's were compacted better on a vibration system.

Getting the dye ratio right for the colour was no mean task either, even with detailed measuring there was some discrepancy evident.

Not something I would bother doing again unless I required miles of the stuff that could warrant a proper set up investment.

 

[bump]

The ones you buy are generally done on the Coote system. This has a 16' x 6' mould system and a vibrating table to accompany it, it'd shake the fillings out of your teeth for sure.