i went to turn the water off at the rising main in a corner behind a cupboard with just a slot to get my hand in,and discovered the wood behind the gate valve and above and below it soaked like a sponge with a nice smell like someone had worn the same socks to the gym for a month. theres a kitchen worktop above then two feet of tiles and then boxed in up to the ceiling. approx 1 foot above gate valve theres a compression tee and from here the pipe goes across then down to a plastic tee with one branch going to the washing m/c and then the other pipe going down below the tiles to go across to sink at opposite end. another pipe comes down from ceiling seperated from rising main by a strip of wood and this is the hot pipe to washing m/c and sink tap. i evantually traced leak to where the 15mm copper hot pipe is welded onto a lot thicker lentgh of lead pipe that travels up to the ceiling and prob beyond. i got a fitting from merchants that connects copper to lead and my question is do i leave wet wood to dry behind pipes or should i rip it out. this leak may have been going on for years. also you would think to look at rising main that it had a leak too as there are droplets of water the full length of the pipe. could this be condensation? finally should a gate valve only be for low pressure and should i change it for a stopcock? sorry for a big long one and all help much appreciated?