New toilet flange install into cast iron in basement and shimming toilet

[Hookmaster]

I have have heard of 3 different flange types: 1) twist n set, 2) tightens with an Allen wrench and 3) has 3 thin flanges and it pushes in. I saw number 2 (pun intended) and number 3 last night at a big box store. I like 2 better than 3 except on number 3 the path of the waste is all smooth while on number 2 it has the small protrusions in which the allen head bolts are. Is one preferred over the others and why?

Also if I need to shim the toilet, what material do I use?

[Archerysniper]

I like to use the hard plastic shims you can find them at all of the home improvement stores. Sheet lead or any other type of lead works good also just pound it as flat as you need it but the plastic shims are way better. Whatever you use make sure it is durable and non-corrosive. Wood will rot out copper turns green and steel will rust away over the years.

As far as the flange go I try to stay away from the ones that go inside the pipe unless it's a glued one used on pvc or abs. A lot of the ones that are made to go inside cast restrict the flow so much they create problems with plugging. Your on the right track though,find one that leaves the biggest opening and is smooth otherwise stuff will hang up and cause clogs.

Check out that tube video site and search {pouring a lead closet collar} their is a great video on the correct way to do it by trades videos.

[Hookmaster]

I'm sure the best way is with a cast iron flange and a lead joint. Do most plumbers do this?

[Archerysniper]

That is the way I do all my repairs when I can not access the pipe. Another thing the video didn't mention is too anchor your flange down to the floor.