Copper pipes from celler to outbuilding

[Shabs]

I have just constructed an outbuilding and now require water and electrics to flow from my cellar to my outbuilding which is approximately 3 feet away. i plan to bury the pipes underground, the electrics going through plastic 15mm pipe and water being carried through copper pipe.

i have searched on this group and understand to stop the copper pipe rusting or becoming weathered etc as it will be buried underground i need to coat it with denso tape.

if the copper pipe is 15mm, what size drill bit will i need to ensure the denso coated pipe will fit through the drilled holes in my celler and through the concrete block of my outbuilding. Also how much denso tape do i need to apply, just 1 layer or several?

Many thanks in advance.

[IMM]

If underground have the water pipe 750mm deep. Run plastic pipe not copper and have it in a sleeve (large plastic pipe). Have the plastic pipe have insulation on it and then push it through the sleeve. have no joints in the pipe run.

[Dave Plowman (News)]

Wouldn't it be easier to use the correct plastic pipe designed to be buried direct?

[The Natural Philosopher]

Don't use copper: Use plastic pipe. Far more relaible underground.