How to install closet flange to cement floor

[Kezug]

Please help me in installing a closet flange in this situation. I have purchased what will be a flange fitting on the outer edge of this pipe.

Is an outer flange ok?

Is the flange you see ok for this install? Too thick?

Do I keep removing all of the styrofoam?

Do I just cut the pipe flush to the floor, and clean/prime/cement in the outer flange, then secure flange to cement with masonry screws?

Before:

Current:

 

[Jadnashua]

FIrst, take that one back and get one with a SS metal ring on it. The all-plastic ones tend to break. Then, to make the holes needed to anchor it properly to the floor you have some choices: lead anchors, Tapcons, or plastic anchors. Each of them requires you to drill holes, the anchors require the largest ones. WIth an anchor, the specific one you choose will dicate the diameter and depth of the hold. Once the hole is made, you may need to vaccum out the dust, then slide it in, set the flange, then use a brass or SS screw to hold it down. The screw expands the anchor to hold it down. A Tapcon is a brand of specially hardened cement bolts/screws. You would use their special drill, then you just screw it into the hole - the hardened metal cuts threads into the concrete like a woodscrew in wood. YOu'd need a carbide drill bit to make the hole, and while a standard drill will work, a hammerdrill will work faster by far.

 

[Sponsor]

 

[Gary Swart]

My favorite method to attaching anything to concrete is the lead sleeve method. Now, I do own a small SDS rotary hammer drill that makes drilling holes in concrete almost as quick and easy as into wood, although I don't use this drill on a daily basis, it is invaluable when I do have concrete work to do. I have tried Tapcons, and while they do work, they are much more costly and difficult to use than the lead sleeves. I use a 5/16" bit, 10-14 x 1-1/2" lead sleeves, and #12 SS sheet metal screws for toilet flanges, and just regular steel elsewhere. Outside fitting flanges are optional on 4", but necessary on 3". The styrofoam is doing nothing for you now, so just remove enough for the flange to slide over the pipe. May I assume you know the flange is supposed to rest on top of the finished floor?

 

[Winslow]

The flange will work fine, I preffer the plastic over the metal ring, which can rust ojut if moisture gets to it. Secured with tapcons is the easiest method. No matter which anchor method you use requires a drill. Any 5/32 masonary bit will work (for the smaller diameter tapcon).

 

[Kezug]

Thanks for all the feedback. How many screws do you think is sufficient?

Also, I have read both that the flange goes on the finished floor and the finished floor goes up to the flange....it can go either way. In this case, I thought to clean and expose the concrete.


But is the outer flange ok or should I get one that goes inside? Also, do I cement the flange to the pvc in the floor just like any other pvc cement work?

 

[Jadnashua]

A SS ringed flange will NOT rust, but the cheaper, painted plain steel ones can and do...get one with the SS ring. Also, if you can find a flange without a socket, that makes things easier since you can leave the pipe long, slide the flange down on TOP of the FINISHED floor, then once finished, cut off the excess pipe sticking through the middle. Those with a socket require you to get the pipe cut off to the proper height before you attach it. Since it is nearly impossible to dry fit pvc connections (it is an interference fit that only fully engages when it has the cement that actually melts the glue), getting it just the right height can be a pain to the novice. Yes, you glue it up like any other pvc joint - clean with the cleaner/primer on both surfaces, then the cement on both, then slide them together, twisting slightly to help spread the cement better.

They put the quantity of holes in the flange that they deem necessary to hold it down properly while ensuring that the toilet bolts get the proper support. This depends on the type and brand of flange you buy...i.e., you should use them all, or at least those either side of where the toilet anchor bolts go.

 

[Gary Swart]

I don't know where your information that says the finished floor can go up to the flange thereby recessing the flange, but it is just flat wrong. It is true that using a thick wax ring can make up the difference when that has been done, but it is not the preferred way to do it. You have the opportunity to do it right. I don't intend to get into a war about lead sleeve vs Tapcon, but I do maintain the sleeve is easier to use. The pro plumbers on this forum all recommend against the plastic flanges and opt for the stainless steel.

 

[Winslow]

two screws on either side of the flange near where the toilet bolts go is fine.
You can glue the flange directly to the cement as long as the top surface of the flange sits at least flush with the finished floor, otherwise you will need a thicker than normal wax.
If the pipe is 3 inch then you have to glue the flage onto the pipe with a 4x3 closet flange. If the pipe is 4 inch then glue a 4x3 flange inside the pipe.

 

[Kezug]

Thanks everyone for taking the time out to help. I will get the SS ring...also, one thing I need to mention is that the floor that I have is like 3/16" thick (not exactly sure but its thin. Its a vinyl (perfect for basement and is water proof)...so not putting the ring on top wont compromise in height and I still will be able to use a regular wax ring.