Depending in which part of the world you live in will depend on what legal fittings are available. in most cases, reducing collars are available which are PVC welded onto the main line.
yes.
Drain, Waste and Vent System. It is all of the Drain and Waste piping and their associated vent piping
Storm drainage piping.
Vent piping is a pipe that runs outside and is connected to the drain line of your home. this helps the water in the drain to move to your septic/sewer.
Yes, be sure to pipe floor drain line properly into water closet piping.
drain
drain
You cant, you have to remove the section of piping and install a new section of piping.
30 cm cheers broA kitchen WASTE pipe is 11/2" in many codes which is utter stupidity as the kitchen WASTE line does become reduced with grease and soap scum depositsIf the WASTE piping is going under ground to connect to the SOIL line (sewer piping) then 2" is strongly recommended as snaking an 11/2 line can be very challenging as the fittings are very short radius
Kitchen drains get blocked for various reasons:There might be a rough bit of piping in the drain. Gradually small things get caught there and eventually build up a blockage.Something large went down your sink and got caught on a bend.Hot water and melted grease runs down the drain. When the grease hits the cold pipes it congeals and forms a layer on the side of the drain, like cholesterol in your arteries. Gradually this builds up.Make sure nothing goes down your kitchen drains except water. That is the solution.
Shower drain goes into a trap under shower. Continue piping from trap to drain line.
You don't, a roof drain is nothing more then a conductor that allows water to enter the storm water piping and then the piping leads to a place of disposal.