gravel path help please

Hi
We have had some drainage problems in the garden, my solution to this has been to dig a great big trench around the edge of the grass to a depth of around 25cm. One edge of the trench is raised sleeper beds, the other side will be a mowing strip made from paved drive blocks.
My initial plan was to fill most of the hole with gravel, put a membrane down and then slate chippings as surface dressing..other half has now decided she wants it all gravel...which will be cheaper but she had one concern if the depth of pea gravel is around 25cm will this still be walkable on or will it be quite difficult to walk on, should I put a membrane down at the base of the trench or is that pointless because of how deep it is?
sorry for the daft questions
thanks
Jim

All gravel can be difficult to walk on - depending on what shoes you wear. I wear wellies so don't have a problem! Girly shoes may be problematic. For older people, I've found not too deep gravel actually helps their mobility - non-slip. Children do get fascinated by gravel and tend to throw it on the lawn, or anywhere else and if they dash about, it goes everywhere. In a small garden it can get messy, and self-seeding plants can result in lots of seedlings in the gravel.

That said, for bigger areas, I'm a gravel fan. Whatever depth you lay the gravel, over time it gets worked down into the soil if there's nothing between the soil and the gravel. Could use black perforated heavy duty plastic, or sprinkling cement over the soil before laying the gravel can stop the gravel 'churning'. I've used old plastic compost bags, thick newspaper then triple bin bags, (all carefully over-lapped) and cement sprinklings all with success. And I never get any drainage problems in the gravelled areas of the garden, no matter how wet it gets.

thanks, do you think that if I dont put a membrane down when the gravel gets worked into the clay...will it improve drainage further?

Maybe, but ultimately the gravel gets pulled down into the soil and the clay/soil starts creeping up to the surface. I haven't got experience with clay, so maybe this doesn't happen as rapidly. Perhaps dig a deeper trench say 8-10ins, put a bottom layer of broken up hardcore type stuff (or something like crush and run) say 5ins deep onto the clay, then the smaller gravel top layer, say 4ins.

When I use my newspaper and heavy duty black compost bags, all the water drains out where the bags overlap, but my soil is quite sandy. If I don't put a peforated membrane down, it's not long before even quite deep gravel gets sucked down into the soil.

thanks,
will probably put down a membrane first then,
do you think I should have pea gravel as the base and then a larger stone (eg slate) as a top dressing? would this be easier to walk on?

Have never used slate. Not too keen on slate with lawn, don't like the colour combination and find slate too "cruel". not a gentle, relaxing shape or texture. But that's only a personal preference. Don't know if the slate would break up if walked on a lot.

Think if you get too many colour contrasts at ground level then it all gets a bit busy. I like calm in a garden and find "less is more". I'd just go with pea gravel. I use limestone chippings, but lots of people don't like them!

Whatever you choose, choose what you like. Ensure the membrane is perforated and I hope your drainage problems diminish. Look up "French Drain" on Google images and you'll get some more details.

thanks for all your help and sorry for all the really stupid questions
Will probably go for the pea gravel all the way down---the wife keeps going on about being able to walk on it and thinks we should put roadstone down and compact it first and then topdress with gravel but I suspect that this might reduce the drainage potential and that gravel would be better for this, I am right or should I concede to the better half?

I've looked at the images on Google on French Drains, which is a bit like the job you're doing, only without any pipes. Some show the trench filled with gradually reducing sizes of "stuff", with the smallest size being on top. So the lower part could be crush and run (is that "roadstone"?) then the gravel on the top. I filled a trench along the side of a concrete sort of path with all sorts of general bits - broken brick, pebbles, broken slab, then covered the top with a good few inches of gravel to cope with water run off. It worked.

Whatever you put down, in time as it gets walked on the gravel pushes down on its neighbour and really firms up.

There is something called the "Brazil Nut Theory" which is about why bigger particles find their way to the surface - larger stones will find their way to the surface through smaller stones. And it is true. (So why does my soil come through the gravel!!) I think it all depends on how deep the trench is and how deep the top layer of smaller gravel is. Deep trench - hardcore + gravel, less deep trench - gravel only, otherwise the hardcore stuff will work its way up to the surface - but it may take many years. Let me know how you get on.