Screeding rails - Screeding

[Adam Ashworth]

Hi, i am going to be doing my driveway in a few weeks. I have picked a lot of information up from the site.

One thing i need to know is when you screed the sand i see that people use rails as a guide. Is it ok to leave these under the blocks or do they have to be removed?

I was told steel pipe is the best to use? Any one recommend anything else?

many thanks

[msh paving]

25mm steel electric conduit aprox £4 a length, never leave in
MSH

[lutonlagerlout]

i have seen 25 by 38 roofing batten used but as mark correctly says 25mm electrical conduit is best
you will need an ally straight edge for screeding the sand off
LLL

[local patios and driveway]

a little tip, when we take the rail out we walk back along the line thats left with a trowel and fill the gaps and footprints with more sharp or glass moving backwards.

[haggistini]

a very straight 3x2 will do if you cant get hold of an ally screeder

[Adam Ashworth]

how do you mean ally screeder? whats is that?

cheers guys

[haggistini]

a lenth of alluminium box section bit like a large ruler about 2-3m long sits atop of your rails after they are set to the right levels and scrapes/screeds off you precompacted sharpe sand.

[lutonlagerlout]

i use one of these but mine is 4.2 M long
LLL

[Adam Ashworth]

Thanks haggistini

Just pick one of those ally boxes up from a diy shop then?

You said you use it to screed of the compacted sand. I thought you compact the sand and then add lose sand ontop - then screed the lose sand?

Thank you for your help

[seanandruby]

no you place your sand a bit high, then go over it a coupla times with the wacker, place your screed rails then screed off leaving your bedding a few ml high to allow for comaction to right level

[specialbranch]

I always use a good straight deck board for screeding you can notch it if needed and if its a DIY job it'll be cheeper than buying an ally edge. for the rails i went to my local scrap merchant and got some 3m long 35mm solid steel bars. There heavy to cart around but you can hit them with a mallet if needed and they wont bend. Set your hardcore up perfectly then then the bars can just sit on and they are the perfect depth of sand.

[Adam Ashworth]

Thanks for that. One last thing regarding screeding; i am doing an area of 45m2. Is it best to screed in stages or do the whole lot then start laying the blocks?

Cheers

[rab1]

stages

[williams]

If you don't float the bars in afterwards (i.e re fill pole holes with sharp,whack down with float and level back off) properly then you will either get nice big rutts along them or nice little humps where they haven't been floated off right.

Another tip if your a bit worried about the float is to do the above and then VERY gently pull a short level over the pole hole using the screeded edges as a guide, if its a bit low top up or a bit high then pull off, but you need to be very gentle otherwise it will cause more damage than the float.

All makes for a job done well. That said i am weird and will notice if things are out by a couple of mm.

[seanandruby]

if you do it in stages, make sure you stop your block work about a metre from the leading edge, before screeding more bedding.