Putting a french drain close to house - Does it need a brick edging?

[NovicePaver]

I want to put a french drain(6 inches wide by 8 inches deep filled with 20mm gravel) close to my house due to minor damp problems.
I then want to lay a patio outside the french drain.
Do I need a brick edging laid on mortar between the french drain and patio to prevent the mortar under the paving slipping into the french drain ?

Or can I simply put some concrete down at the outside edge of the french drain to make it more solid and simply lay the paving on that?

I'd rather not lay a brick edging as the width in one section becomes so narrow it would be difficult to generate a random pattern.

[Tony McC]

What about enveloping the 'French Drain' with a permeable geo-textile?