Laying patio - Recycle old patio?

[diymark]

Hi Everyone,

New member to the cabin so please be gentle!

I have an L shaped patio area in my back garden. Part of it runs along the back of the house but it is breaching the damp course. So I need to lower it.

I need your assistance on a few matters as I am planning to do this work myself and I have never layed a patio before.

I would like to recycle the old patio slabs if possible. I was contemplating lifting flags, and digging out 330mm and then relaying the slabs (which are 50mm thick), adding 50mm of hardcore, wack it all and then lay 30mm of mortar and lay new natural stone flags? OR, should I break up old flags and toss them in with 100mm of hardcore and then wack? OR lift old flags and get rid?

Another point I need assistance on is the Damp course. If I put a drain channel along the back of the house, am I right in thinking that this only needs to be 75mm below damp course, which in turn means the patio area only needs to be 75mm below damp course? This would mean less digging out? If I don't put a drainage channel in, then obviously the whole of the patio area needs to be 6" below DC, which means more digging out?

And finally in certain parts, the patio area seperates the house from the lawn. Digging down the patio area will mean I will have to put a retaining wall in front of the lawn. Should this wall be built first and then the patio layed? And as for a retaining wall, can I use a railway sleeper(just from a decorative perspective)? And if so, Can I bed this on cement? Or should I build a wall? If so what are the rules i.e foundations etc etc.

I was thinking of a wall and then cutting some of the natural stone to size to use as a cap on the wall?

Any advice would be greatly appreciated and I thank you in advance for your help.

regards,

Mark.

[Stuarty]

lift the old slabs and sell them, its surprising the amount of slabs ive sold over the years lol

regarding the drain and levels, even with a drain installed, it still needs to be 150mm below dpc, its more to do with splashback than water depth if you know what i mean.

You can use a railway sleeper, no need to bed in imo, just concrete in a few 100x100 stabs to support the weight. Build the retainer from whatever material you choose first. Then do the paving last, afterall you dont want to damage/stain/disrupt your nice new patio. And the founds of the wall will sit under the patio a bit.

[Tony McC]

Using old flags/bricks as sub-base

DPCs

Sleepers as retainers

[diymark]

Thanks alot for the advice and replies.

Appreciated

Mark.