Setting out

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I am creating a small rectangle of 90deg herring-bone paving (with a flat but not level surface) to link my porch with my driveway, replacing some grass that gets suicidally slippy in the wet season. I'd be interested to know how you would set out guidance (strings or whatever) in this particular circumstance, where the subsoil is natural subbase, cracked but virgin shillet. I have plenty of roadpins from my other domestic paving job, but my chances of getting them into the ground here at all are close to zero, let alone exactly where I need them to be.




I will use the existing iron channel (top of main view) as one reference (for a run of 1.7 m to give you a scale), and the two sides will come out for 1.8 m orthogonally (at least in their plan). Of course this is real life, and some compromise on slopes is needed. I've no problems with what I need to achieve - I can visualise it comfortably.

But I am a bit perplexed as to the best way to actually get the levels right. I can speed-lay soldiers accurately to string very happily now, but I know from experience that when a stringline can't be established it's rather more tricky (especially if not level). Would you attempt the roadpins game in this kind of ground? Do you have other tricks up your sleeve**? Would you do it all by eye?

I probably will do it in stages of dead reckoning and just hope when I've done my four sides of soldiers the start and the end actually join up in all three dimensions! So:

1. lay along the iron channel, which will give me top left and top right references.
2. use a plank and spirit level to set out each side, using a string to guide orthogonality but NOT the level
3. Leave to harden then use a string along the bottom run.

Interested in any comments you might have!
Regards - Mike -

** another option might be to temporarily bed a couple of blocks in the driveway at stage 1. so that their surfaces can be used as reference for strings which would then give orthogonality AND level correctly for the side runs.

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You've more or less solved it for yourself, Mike!

Lay the soldier edge course along the channel grating, as you said.

Set a brick on a bed of sand just beyond the end each side run, in a roughly orthogonal position. Don't worry about level at this point, although you can, if you wish, set the top of the brick to the projected level.

Set up string lines stretched from each end of the channel course over the top of the temporary bricks, and then use the 3-4-5 triangle method to check for accuracy. Once the sting lines are correctly positioned, they can be weighted in place behind the temp bricks, to generate the required tension, and then simply lay the blocks. :)

You can use a straight-edged timber to check the level and the alignment and then piece-in the stop end.

Another option that we use in situations where it's impossible to drive in road pins, is to use a decking sheet or timber baulks set just outside the working area, and then knock in nails to act a 'mini road pins'. The string line can be stretched over another piece of timber to give correct level and alignment and then fastened to the nail for anchorage. Remember to weigh down the decking sheet/timber baulk if there's any chance of the tension from the string line causing it to shift during the work.

Does that make sense?


I don't envy you having to reduce dig that ground to get it down to formation level. What a way to spend the Bank Holiday!

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And 'tis done! Just requires its final whack and a bit of turf re-alignment. (Much to the relief of my arms and the crowbar...... Anyone want a large pile of shillet?)

The block on pile of sand technique worked very well - thanks for the advice.

The idiot grin on face is because our digital camera is a bit naff by current standards and the LCD viewer so faint my wife is peering through a toilet roll centre to be able to make anything out.

- Mike -

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Excellent! Well done, Mike! :)

I've just had a request from a firm in Maldon - they're looking for block layers, if you're interested in a new career! ;)

VACANCY DETAILS
Blockpavers wanted
Maldon Company require block pavers for immediate start.
Previous experience an advantage.
Tel: 01621855965

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Thanks Tony, but I reckon Devon to Essex every day would be even more exhausting than block laying!

Slightly off at a tangent, but a little academic question for you, please. How important is it to whack immediately after laying, for domestic very-light-use footpaths? I have the little pocket handerchief in this thread and about, I guess, 25 m2 of my other pathwork awaiting final whack.

I have a local family builders, very close, convenient and cheap but I won't be able to hire their whacker for a month, maybe two. The other option is to go into town and pick up a whacker for £30 (1 day minimum charge) from the 'impossible to park outside' hire shop. That all seems a bit daft for a half hour usage.

What are the downsides of delaying whacking a low traffic footpath? (There's plenty of kiln sand down the gaps.)

Cheers. - Mike -

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I wouldn't worry about it, Mike. If you were running cars over the paving, then I'd say get it done as soon as, but for the amount of hammer it's going to receive from postman and the milkman, you'll be safe enough waiting until you've the rest of the paving ready and then have a borrow of the wacker plate. :)