Just a couple more points after Eric's excellent post.
Pipe slice is excellent, I have 22 and 15mm sizes as well as several of the handscrew type and would never willingly use a hacksaw note however that they compress and round over the end of the pipe slightly which is great for pushing into fittings but I've found makes it very tight to insert a bending spring so the pipe end can need to be opened out again slightly, easy to do or use a proper bender.
Not meant for the OP but in case of any beginners here,
*Buy a pair of shears to cut plastic pipe rather than a Stanley knife If you can, they are cheap and well worth it.
*Never use a pipe whether copper or plastic with a ragged end on a push fit as it will damage the O ring and probable fail.
*Always use pipe stiffeners, metal ones are thinner and reduce flow less than plastic and practice first with a demount-able fitting so you can open it up with a pipe pushed home and see what it takes using plastic push fit connectors I've seen several instances when the pipe hasn't been pushed fully home where they might not leak initially but will most likely blow off under pressure later. You have to get a feel for them as there are 2 points of resistance and it's easy to think it's done at the first, you have to push fairly hard to get past the second part which is a definite stop. Once you've done a couple mistakes won't happen.
* Support plastic pipe properly, it sags like **** especially when filled with hot water
I was called out to one as a favour and the guy had not only not pushed the pipe fully home but had put Fairy Liquid on it as well, it pumped out a lot of water before they managed to turn the mains off.
On the other hand one of my neighbours in a then 5 year old bungalow called me round to look at damp patches on her hall walls, they were internal walls, concrete floors covered by a floating T&G chipboard floor over polystyrene insulation slabs, I knew instantly what it was as I'd seen 2 other cases over the years. Poorly made or faulty copper joints under the floor "pinhole" leak causing water to run and flood under the insulation and along to the walls, close inspection showed it was very extensive into the bathroom, kitchen, lounge and a bedroom. Told her to contact her insurance company who moved them into rented accommodation, stored their furniture and had repairs carried out over a period of 4 months, I believe the total cost was in excess of £70,000 :shock:
Over the years I've installed a huge amount of pipe, both copper and plastic and apart from minor issues haven't had a problem with either though my own house has a minor leak at the minute from a copper c/h manifold feeding 8mm microbore (cr*p), not my work btw :lol: it's in an awkward place, coupling nut is seized and I'm putting it off until I can get motivated to make a **** of a mess. Did I say I HATE plumbing!