Bedding for riven flags

Patio flagstones (slabs), concrete flags, stone flags including yorkstone and imported flagstones.
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Paul Marbre
Posts: 3
Joined: Thu May 02, 2002 11:00 pm
Location: Chester

Post: # 262Post Paul Marbre

I have 11m SQ patio to lay using Wickes riven Wentworth flags. This includes a circle with square off kit.
I intend to screed the area with sharp sand. Do i need to mix 1 part cement with the sand?
I want to use a dry mortar mix for the joints. Do I need to butter joint? I'm worried about being too slow for this to be effective!
Do I start with the centre of the circle and complete the square or lay a line of flags up to the circle to stand on?
I'm starting to worry now - they're being delivered tomorrow!
Amazing amount of info on site - great to see.

84-1093879891

Post: # 263Post 84-1093879891

Use a 10:1 mix of grit sand and cement for bedding. Don't add any extra water.

You don't need to butter the joints, but the finish will be far superior if you do. The mositure from the butter will help initiate setting in the dry mortar jointing mix.

How you lay the circle and square depends on the site. I find the easiest way is to lay one edge and then work across, making sure the centre is higher than the edges so that it drains adequately.

Setting screed rails about 150mm outside the line of the paving, and then using a wooden stake tapped in on the centre point with 25-40mm of fall to the outside edges allows you to screed off with one end of the screeder 'anchored' to the central stake and the other travelling over the screed rails.

Some folk like to start in the centre and work out to the edges, but this need you to determine the centre of the circle exactly, and, if you're working to a solid edge, such as a wall, it's all too easy to realise that you're 25mm out and the whole lot has to be 'nudged' one way or t'other to fit in the last few flags.

Once the whole square is laid, you may need to adjust joint widths to get a balanced look.

11m2 would take a tradesman around 2-3 hours, complete. If you allow yourself a full day, you should have plenty of time. Don't worry too much about the pointing; concentrate on getting the ground covered and you can catch up with the pointing the following day if necessary.

Let me know how you get on. :~)

Good luck!

Paul Marbre
Posts: 3
Joined: Thu May 02, 2002 11:00 pm
Location: Chester

Post: # 272Post Paul Marbre

Thanks for the prompt advice Tony! This and other info on your site enabled me to lay the patio by 5PM yesterday. Still some finishing off to do though. I need a cutter as the area is a fixed size. It's not perfect but it looks damn good! It may not slope away from the house and the middle of the circle may not be higher than the outside, but hey.. next time..
I now realise why all these techniques are used.
I still have to add the dry mortar mix to the joints so I'm off to have another look at your site for the right mix to use.
If I do need to relay one or two at a future point is it simply a case of removing the hardened mortar mix from beneath and replacing with fresh and tapping down to desired level?

Thanks again Tony!

84-1093879891

Post: # 273Post 84-1093879891

Well done, Paul! :)

As long as you're happy with the results, then that's all that matters.

For your jointing, use a 4:1 mix of building or silver sand with cement, and, if you do need to relay, the easiest method is to prise out the flag(s) in question, scrape out the top 20mm or so of the bedding and replace with a wet 6:1 mortar, then re-position the flags and tap them into place with a rubber hammer. Any excess mortar bedding should squeeze up between the joints.

This is a better method for replacing individual flags within a patio, but, if you're relaying 3 or more adjacent flags, a semi-dry bed can be used.

Paul Marbre
Posts: 3
Joined: Thu May 02, 2002 11:00 pm
Location: Chester

Post: # 276Post Paul Marbre

Hi Tony. Is this 4:1 for a dry mix to brush between the flags?
Does it need compacting in afterwards?

Cheers

Paul

84-1093879891

Post: # 277Post 84-1093879891

Yes - it's 4:1 whether it's a dry mix or a mortar. If you choose a dry mix, brush it in, then compact it as thoroughly as you can with a jointing bar or length of bent copper pipe.

There should be enough residual moisture in the sand and the joint itself to initiate setting, but you could always encourage it with a light sprinkling of clean water via a fine rose fitted to the watering can. :)

I prefer mortar for pointing, but I know it can be a nightmare if you're not confident in handling it and avoiding too many stains. Still, it's worth trying it out in a discreet corner - you never know, you might have a natural talent! ;)

Have you taken any pictures?

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