The Brew Cabin

Posted: **Sat Sep 11, 2004 8:07 pm**

Hi Tony,

Thanks for an absolutely fantastic site, which I've been using to lay a patio, with enough success to impress the wife.

progress to date

I've got a slight problem though which I'm hoping you can help with.

I've used edging blocks laid on a concrete bed and haunched as you recommend. There's no mortar between the blocks (which are charcoal Eaton chamfered ~10cm cubes), and in a couple of places there's a mil or so gap between blocks. I've got a slight fall across the patio and where these gaps occur on the lower edge, they encourage the rain to channel out through the gap, taking the kiln dried sand with it.

I'm wondering if there's some kind of (magic?) product which can be squeezed into the gap to fill it to prevent this happening. Does anything exist? Should I have mortared beween the blocks as I laid them? To be honest it's going to be hard to get anything in there, it would have to be forced down a very thin tube.

I'm wondering if an alternative solution is the ant-protection resin (which I'll need to put down anyway at some point), as I imagine this would lock the sand in place.

On a very similar issue I've got to lay a curved path from the patio to the house. I'm not planning to trim down the edging blocks so I'll have angled gaps between the blocks. What can I fill this with? I've seen your guide for black mortar which would do the trick. Is it best to fill gaps when laying the blocks? I imagine it's fiddly trying to do it afterwards.

The curved edging will be containing rectangular concrete blocks (as for patio, see link) shifted sideways a little each row, so I'll have triangular gaps either end. I'm not keen on cutting in both sides of 75 rows, so I was wondering about just filling the gaps with sand. I'm concerned how this will work and look. The gap each side will be a triangle of shorter sides 15cm and ~3cm. Is a sand-filled gap this big asking for trouble?
Should I try and fill inwards with mortar to make a rectangular 'slot' for the paving blocks?

The edging and paving blocks are different sizes, so I can't just shuffle each row (including edging) a little sidewards.

Sorry this is a bit of an essay. To summarise:
- how do I stop the rain taking kiln dried sand out through thin gaps in edging?
-how can I fill gaps between 2 edging blocks, and between paving and edging, for a curved path, without trimming blocks?

Thanks for any help in advance.

Thanks,
Tom

Posted: **Thu Sep 16, 2004 10:49 am**

I think you're worrying unduly. Eventually the jointing sand stabilises itself and no more will trickle out. This is acheived partly by detritus being washed into the top few millimetres of the sand and forming a 'seal', and partly by enhanced interlock between sand grains as the paving becomes more established. Give it a couple of months and I'll bet the problem has (more or less) disappeared.

Moving on to your curved path, judging from the photos on your site, I'd hazard a guess that you could slew each successive course by a few mill, so that each course is 'square' to the edging. This will result in the transverse joint being slightly wider at the outermost edge than it is on the inside edge, but as long a sthis is no more than about 8mm, there should be no real problem.

Do you know the radius of that curved path?

The Brew Cabin

Curved edging - What do i do with the gaps?