Sorry no idea but keen to see response, and learn about stacks, as I've got similar project underway :) on a smaller scale :)

I wouldn't worry about most of the weeds but take out the ivy and brambles and do try to remove any trace of the mares tails if you can. They are extremely deep rooted and very difficult to eradicate. They will reappear in the cleared garden and you should glyphosate them every time they come up - it will take a while but some people have managed to get rid of them this way. However if you are simply going to sow a new lawn I guess very regular mowing will discourage them eventually. If your turf stack is big enough it should heat up enough to kill of any annual weed seeds. Dandelions are quite easy to remove from turf once its cut. You will probably find you have cut the roots off half way and they will regenerate in the ground but you can easily dig them up when they do.
Its a pity to waste the turf at the tip.

I have a concern about the mares tails but would stack the turf anyway. When I use loam from our own turf stack I fit a home-made seive over the top of a wheelbarrow and rub the loam through the seive. This way I can see what I am producing and remove anything unwanted before use.

If there is a lot of turf and it needs riddling (proper word for putting soil through small holes) then I have the plans for a very efficient and easy way to do it. Will publish them if people feel the need.

Thanks guys most helpfull. There isn't as much mares tail in the front as in the back but it's a concern. I had thought about the idea of sieving the compost before use to make sure I'd got rid of it all. Glad you've said it's a good idea. Owdboggy I'd really appreciate the details if you wouldn't mind posting them or pming me.

I think I might build a stack in the front now. We've got a little courtyard where we keep the bins so I could put it there. As its south / east facing (depending on which wall / fence) it will get much more sun than the north facing back garden. Would that be a reasonable spot?

From what I've read it sounds like the best way of creating a stack is to pile the turves grass side down and leave open. Will it make any difference that I am digging it up by hand and don't have even sized turves. Also as I was being a tad lazy I'm digging it up with really long grass. Saying that I'm seriously considering hiring a turf cutter in which case I'll stop being lazy and will strim the wilderness (lawn) lol.

Thanks for all your help it's much appreciated.

I would strim the grass before you lift it, Sam. It makes all the work so much easier and more pleasant. When I removed our lawn I did it by hand, the turves were of a 'similar' size but it definiely varied. This actually helps as the turves then overlay each margine and the stack holds together better.

How I made a large riddle to sieve lots of soil.

All measurements are in Imperial because I have not yet mastered metric. And they are approximate since I used what was at hand.
Using 1.5 in by 1in roofing lath timber I constructed a rectangle of 5 feet by 3 feet. The corners were butt jointed and strengthened with corner brackets. (This size was made because that was the size of piece of chicken wire I had available.)
I stapled a sheet of 1/2 in chicken wire stretched tightly to the frame. To give more stability and to stop the mesh sagging I also stretched straining wire every foot across and down, woven through the mesh.
Then I fastened legs of same size timber to the top of the frame so that it sloped about 60 degrees. (Need to experiment to find best angle). When in use I also used a couple of tent pegs to stop the frame moving backwards when soil was thrown at it.
Dry (and it needs to be dry) soil is thrown (not too hard) at the top third of the frame. As it trickles down larger than wanted pieces stay on one side and smaller pieces go through.
If you wanted a more robust and longer lasting gadget than you could use the wire mesh sold for outside aviaries.
The angle of the legs should be such that the soil trickles down and breaks up as it goes, too shallow and it sticks, too steep and it falls off.
This does not work on wet or clay soil. Sorry, but then neither does the old fashioned garden sieve. Either way it is still hard work, But at least you do not have the weight of the soil to lift as in a conventional system.
No photos, did this before we owned a camera.
But daughter and I riddled over 200 tons of soil this way.

Brilliant...... I now have a purpose for skip corner. Do you lay turves green to green brown to brown, or all green down? Seen conflicting info.....

I always go 'green down'.

Grass to grass and soil to soil, until I get bored and then just toss them on. I did cover the heap with black plastic though as it did not seem to be rotting quickly enough for us and there was a lot of grass growth on the top.

Brilliant thanks everyone. Much appreciated. If it ever stops blinking raining I'll start my turf stack :-))