Patio - drain towards house or onto grass?

[InfAddict]

I'm building an Indian Sandstone patio in my back garden, approx 40m2 in size. The patio will run the full width of the garden and start against the back of the house and run down the garden to the grass.

There is only 1 gully against the back of the house and this is kind of central where the kitchen sink also drains into. I believe the whole back of the whole (which is an extension) was actually built on top of the sewer, so my guess is that this gully feeds back in towards the sewer under the extension, rather than out into the garden.

My question is should I a) use the normal method of draining the patio (via a gradient) towards the grass or b) towards the house and have some sort of V shaped channel near the house to guide the water from the patio into the centrally located gully? If I drain to the grass there's a danger of flooding the grass as there's no way of getting rid of the water except the natural grass drainage... but maybe this isn't as big an issue as I think - I'm no expert.

I have read the excellent drainage pages showing the various options I have if I choose to fall back to the house. I am using Indian Sandstone, so I wouldn't want to use a pre-made block paving type of channel. How else could I achieve this?

Flag sizes are 560x560, 560x275 and 845x560. Could I use the 560x275's along the house edge to create this V channel toward the gully or would it be better to either cut them or choose a different stone/flag/block for this channel.

Any advice of the options available is much appreciated. If at all possible I don't want to have to lay linear drains, land drainage etc.

[Tony McC]

If the grass/garden can cope with all the extra surface water being drained onto it, this would be the most environmentally friendly option, but if the ground is poorly drained, then draiuning towards the house and directing water into the existing SW system is your only real alternative.

Using a v-channel is simple and effective and quite discreet, particularly if you don't want to install a dished or linear channel. Using the 275mm wide flags all the way along the house would make for a fairly distinctive "band", and I would consider using that size of flag as a virtual edge course to ALL the edges, just to give the impression of design rather than a choice that was forced upon you.

[RodgertheBodger]

This may be a bit late to be of help - but when deciding whether to go towards grass or house, remember this. If you ever put weed-killer / cleaner - or any other nasty stuff on the patio - you'll wish it drained towards the house. You'd be amazed the number of times I have had to re-seed/turf a narrow strip of dead lawn!