How low can you go ?

In terms of fall with a 4" plastic underground drain Just bought my LAST ever house ( bungalow) and yet again I need to do some repairs. The drains blocked when we arrived. Got them moving, then power jetted and removed a lot of " scale " Should be ok , not so . the path that they are under has dropped a little, taking the pipe down a tad with it. Kangoed away the concrete and found the bloody things are level In fact if you wanted to lay something level, they would be good " on the bubble" of a 6foot level. Have you guys had success with less than 1:60 for a 4inch placcy piperun. Not a desperately hard job to uncover and lift slightly , then replace peashingle. But there is very little covering to play with - so a workable fall would be the way to go . Thanks guys.

Drains will only block at bends, or displaced joints .... or if you fill them with rags.

So a new drain run in plastic, even without the normal 1:40 fall should perform OK.

If you can, just install an inspection chamber, and give it a blast once or twice a year

Agree with woods, a single plastic drain pipe will still run even with half the recommended fall. We have had success with as little as 4" over 8m.

Exellent. I`ll check the remaining part with a lazer level etc. That 8 meters is close to the length of run I have .Also I have put in a mini acess chamber in place of a badly done rodding point .Many Thanks, Guys.