shower pipes

hello all , my first questions for you . I want to remove the old bath , then put a small mixer shower in it's place . The bath tub pipework is connected to the combi boiler , would it be ok to use the same pipe fittings for the shower . And is it ok to use compression fittings to do the job with , they look quite easy to fit . thank you .

It's my understanding that typical compression fittings are not allowed in enclosed spaces, so no, you cannot use them. Hidden behind the wall for possibly decades, a good solder joint is hard to beat. An approved alternative is a slip-on fitting called a Sharkbite. Google them, and see.

I have read somewhere that you need a Non Return Valve , if the shower is to be connected to the mains water pipe . Do i need one ? . Also do i need any waterproof material under the tiles , if yes what ?

I was thinking of making the shower concealed , but the wall i was going to put the pipework , shower valve etc in . is only about 75mm thick . it's a single breeze block , so it should'nt take no time to gouge out for the pipework . What's worrying me is the Mixer Valve may be too thick for the wall . and do you have to leave somewhere ( hatch ) maybe to be able to get at the Valve etc if something goes wrong . ? please advice . thank you .

A handheld shower requires a vacuum breaker to prevent it from sucking up polluted water if it is left hanging into standing water and there's a hiccup in the supply pressure. Other than that, no special requirements. In the USA, they require an anti-scald valve when it controls a shower. That may not be common where you are. That type of valve prevents radical temperature changes if the pressure changes in one supply (such as may happen when someone flushes a toilet or turns on a large flow in say the cold).

The wet wall (where the shower head and valves are) in my shower backed up against a pocket door, and access would not be easy if maintenance was required at the back. I chose to use an external mount control valve. I think I heard they stopped making this model, or at least stopped importing it into the USA. They made a shower only version as well.

I might just get a fancy shower and install that instead of trying to hide the pipes . thanks anyway .

I was going to put a Non Return Valve ( Check Valve ) at the other end of the shower enclosure , so if i need to get at it for any reason it should be easy to get at , just lift a few floorboards . Is it better to put a Valve on each pipe Hot and Cold . thank you .