Rough plumbing for toilet flange is too high

[BlueCanyon]

Not exactly a tile question, but I know you guys can help me.

We are finishing a roughed in basement bathroom, and the 4" ABS toilet pipe sticks out of the concrete slab about 3 inches. Last night I went to both OSH and HD, and found two kinds of toilet flanges.

The one from OSH slips on the outside of the 4 inch toilet pipe. It is metal, with rubber inside, and you tighten up these bolts to kind of squeeze the rubber onto the ABS. There is also one from HD that slips on the outside of the 4" pipe, but seems to just sit there (or maybe you glue it??).

The one from HD actually sits inside of the 4" toilet pipe. It kind of tapers in.

So.... if we use the one from OSH, we need to chip the concrete out - probably 1.5" deep - around the 4" pipe. If we use the one from HD, no problem - it just slips inside the 4" pipe, but will the tapering cause any problem when flushing?

Question is ... is it better to chip out the concrete and use the outside flange, or use the tapering one that slips inside the 4" pipe? And if it is the tapering one, do we use ABS glue at the connection?

Thanks again for all of the help!
Mary Ann

[ckl111]

It's best to chip around the pipe, cut the pipe to the correct length and then use the flange that glues to the outside of the pipe. It's probably cheaper than the clamp on one and you really don't need to chip much away.

You MUST use ABS cement to glue the flange. Dry fit the flange to make sure the flange is at the right height before gluing. You have one shot to get it right. After 30 seconds, you will not be able to reposition the flange after gluing. If the flange is not the adjustable type, make sure the bolt holes are lined up properly when you are gluing it down.

I have used the flanges that glue to the inside of the pipe in a bind but it is obviously not as good as the other one because the diameter for the sewage to pass is smaller. Some municipalities may not allow them for that reason.

[BlueCanyon]

Great. Thanks Colin.

Somehow I just knew that the easy way out wasn't going to be the best.

Mary Ann

[ddmoit]

Mary Ann,

Here's a liberry link you may find useful... http://www.johnbridge.com/vbulletin/...ad.php?t=40603

[BlueCanyon]

Thanks Dan. I have already got that printed out and nailed to the wall next to the terlit.
Mary Ann

[jdm]

Since you've got a 4" waste pipe, and toilets function just fine on 3" pipes, using a flange that affixes to the inside of the pipe is not such a bad idea. Remember that the flange should sit on top of the finished (tiled) floor.

And as for positioning the flange, you want the narrow part of the bolt slots (not the bigger square area) to be on either side of the pipe, so that the bolts each wind up at the same distance from the wall. The flanges with the metal rings that can be turned after the flange is installed to align the bolt holes are easiest to use.

And finally, I have been advised by real plumbers (I just play one online) that it is important to put a screw in every flange hole to be sure that the toilet stays put.

[TedL]

The outlet from the toilet will be a smaller diameter than the "pipe" on the flange that mounts inside, thus the flange will not be a bottleneck. Make it easy on yourself; the extra work does not buy a better installation.

Make sure use use an ABS flange and ABS solvent, unless you use a "twist and set" which uses a neoprene ring to seal.

Use lead anchors and stainless steel screws to secure the flange to the floor. drill holes before tiling; cut tiles around the anchors. Mount flange after grouting.

[BlueCanyon]

Hey Jeff - Thanks for the good info. I was following along just fine until I got to your last paragraph.

It is important to put a screw in every flange hole.... Please, please excuse my total ignorance on the subject of toilet flanges, but I've got four holes and six holes in the two flanges that I've bought. (This is other than the bolt slots.) So the bolt slots are for bolts that then stick up and go through the bottom of the toilet base, right? What are the other holes for? Does this mean that I am to drill holes into the concrete below each of these screw holes and screw the flange itself into the concrete? If so, how would I go about doing that?

Mary Ann

[jdm]

Yup. You screw the flange to the floor. Ted covered it, but I'll repeat.

Position the flange over the concrete subfloor and mark the position of each screw hole. Remove the flange. Drill a hole into the concrete (using a carbide tipped masonry bit and preferably a hammer drill (if available)) to accept a lead anchor. You can get the anchors and matching screws (and the bit) at your favorite big box (if any big box can truly qualify as "favorite"). Tap the anchors into the holes.

When you tile, notch the tiles so that you don't cover the anchor holes. After the grouting is done, permanently connect the flange to the pipe and install the screws into the anchors.

[BlueCanyon]

Jeff and Ted - THANK YOU.

Ted's post occurred at the same time I was typing, so I had missed his explanatory post. Thanks to both of you for taking the time for such a newbie question.

Looks like another fun weekend project.

Mary Ann

[TedL]

Jeff & I were composing at the same time. He's given you good tips. If you can borrow a hammer drill, it should take about 30 seconds per hole to drill for the anchors. Make sure to match the anchor size to the screws, which you want to be #12 or 14.

Just curious...where are you located that ABS is available? I haven't seen any in NY for a long time, since PVC got cheaper. I can't even find fittings to do repairs/extensions on my home.

As Jeff said, the "loose ring" style is forgiving in that it lets you reposition. The "twist and set", which is not glued, is also easy in that regard. It can also let you install a PVC flange on ABS pipe, if you can't find matching materials.

[BlueCanyon]

Ok, I'm off to the store armed with info.

We're in the Sacramento area. Every inch of pipe (and believe me, we've see every inch of it!) is ABS. The Home Depots here are full of ABS pipe, fittings, etc., so I guess it's the norm here.

Mary Ann

[jdm]

ABS vs PVC is a very regional thing. In NJ it's all PVC.

I think it all depends on what type of toxic fumes people prefer to breathe during a fire.

[BlueCanyon]

[ckl111]

Hi Mary Ann,

Jeff is absolutely right about using the "inside" pipe on a 4" pipe. I was thinking about the ones that go inside a 3" pipe when I was posting which are quite a bit smaller but still work.

If you are just attaching tile straight to the floor you may find that the "inside" flange may actually sit higher on the pipe than the one that goes on the outside because that taper sometimes adds height to the connection. Even when the pipe is cut flush to the concrete, the flange may sit 3/4" to an inch above the concrete which is usually too high for tile on concrete, even with ditra. You may end up having to cut the pipe below the concrete which is a real PITA to do. I have used angle grinders, dremels and even a sawz-all to do it but what a PITA. If someone can suggest an easier way to do it, I'm all ears.

All I can advise at this end is for you to take a good look at the different flanges and how it connects to the pipe and see what is best for your situation. Each manufacturer of ABS fittings may have slightly different designs so you have to look at what's available at your local store.

Ideally, the most you want to do is cut the pipe flush with the concrete and maybe chip away a 1/4" of concrete around the pipe if you have too.

I hope by looking at the fittings you know what I am talking about because it will save me a lot of typing trying to describe it to you because I'm a hunt and peck typer.