This technique of growing a 'hedge on legs' is called pleaching. I've never personally seen it done to Leyland Cypress but there is an example here. They grow very fast, in my climate at least, and you would have a constant pruning/clipping job on your hands. If you ever let them go they can turn into monsters.

The consensus seems to be that Leyland cypress are not recommended for the southeast as they tend to be rapidly decimated by either seridum or botryosphaeria canker.

not a good idea....L.C will become a big tree.... unless you want big trees as a hedge

LC makes an good hedge in the right climate BUT it must be pruned assiduously for ever. It is the failure to cut regularly that causes all the trouble. Many large growing trees can be used as hedges, Beech and Hornbeam for example. The limiting factor is the amount of effort required to keep them as hedges, not the nature of the tree per se. The link I posted link shows that the OP's idea will work under the right conditions. But it sounds as if s/he doesn't have the right conditions.

This is yew, rather than LC but it shows the kind of dedication needed to keep up a pleached hedge.

It really has to be a matter of personal taste, Embo. Pleaching has long been used used in historic and modern formal gardens. There is one I pass frequently which is done with Whitebeams against an 18th century limestone wall in a town garden. It very effectively stops passers by peering over the wall without taking up too much space in the small garden. It looks lovely in my opinion and, given the context, far from 'dumb'. Whether the OP has the time, skill and context to produce the effect well is an unknown. Done badly it would indeed look awful.

Doesn't sound like the same exact situation. For one thing you are talking about deciduous trees. And an 18th century limestone wall. That is probably an appealing feature just by itself.

Ive always hated the LC because of what it does in your photo .Now this year I noticed the the green giant(aka thuga) is doing the same thing :(

@sam_md, mine were about 2x tall as yours, haven't had disease issues at all. However, I did have to top these and cut them back by about a third which made them kind of hideous (we had an ice storm that ravaged them). They look fine on my side of the fence because I had maintained them. On the neighbors side it's bare branches and looks awful. Now I wish for disease so I can get my wife to agree to take them out completely lol. Consider yourself blessed.

Generally, in most climates and most situations, it's idiotic to use LC for suburban screening. GG is not much better. Rural screening (+5 acre lots)...maybe. But leylands on the east coast are almost always a disaster in the long run. It was great being in AU and NZ and seeing so many picture-perfect hedges of a proper plants for the role, pittosporums. Or various other subtropical lauraceous shrubs (sensu lato). You could get very close to that look here with various hybrid Asian hollies (I'd skip I. opaca!*) but - you almost never see it. Most American "landscapers" are too ignorant, and most American nurseries too greedy and dumb...sorry, just telling it like it is. There could be pockets of exceptions like the PNW...I did see generally better landscaping there than most of the eastern US (with obvious exceptions like the most genteel, old money parts of the Philly Main Line, or Long Island...probably parts of Atlanta, Richmond, etc.). But it wasn't like various Commonwealth countries either.

Took this video recently of some farcically awful looking leylands in the new-money suburb of DC where I grew up. I remember seeing this plant become the rage in the late 1990s, slapped up between every McMansion and the roadside. This is how they all look now. Diseased, misshapen, blown over by storms and heavy snow...utterly hideous!

* although there are a handful of denser, darker green forms.