Cork Underlayment.

[loubob]

Hello. I would like to know the proper way to install cork underlayment in a bathroom located in a high-rise condo. Per code the tile flooring must go under the toilet flange.
So is it acceptable to bring the cork right up to the toilet pipe? Should a moisture barrier be used under the cork underlayment? Wouldn't a leak at the flange go under the cork and be unnoticed, growing mold perhaps?

Using 1/4" cork underlayment with approved adhesive and laying tile over. Removing cast iron toilet flange and replacing with PVC, 4" that fits inside cast iron pipe.

Let me know your thoughts.
Thanks,

Luis

[Jerry Peck - Codeman]

Luis,

Per code the tile flooring must go under the toilet flange.

The code does not specify that, below is the code requirements, I have left a few subsections out which are not applicable to the question:

- From the 2017 Florida Building Code, Plumbing (underlining and bold are mine, my comments on in italics)
- - 405.3 Setting.
- - - Fixtures shall be set level and in proper alignment with reference to adjacent walls.
- - - - 405.3.1 Water closets, urinals, lavatories and bidets.
- - - - - A water closet, urinal, lavatory or bidet shall not be set closer than 15 inches (381 mm) from its center to any side wall, partition, vanity or other obstruction, or closer than 30 inches (762 mm) center to center between adjacent fixtures. There shall be not less than a 21-inch (533 mm) clearance in front of the water closet, urinal, lavatory or bidet to any wall, fixture or door. Water closet compartments shall be not less than 30 inches (762 mm) in width and not less than 60 inches (1524 mm) in depth for floor mounted water closets and not less than 30 inches (762 mm) in width and 56 inches (1422 mm) in depth for wall-hung water closets.
- - (subsections not included)
- - 405.4 Floor and wall drainage connections.
- - - Connections between the drain and floor outlet plumbing fixtures shall be made with a floor flange or a waste connector and sealing gasket. The waste connector and sealing gasket joint shall comply with the joint tightness test of ASME A112.4.3 and shall be installed in accordance with the manufacturer’s instructions. The flange shall be attached to the drain and anchored to the structure. Connections between the drain and wall-hung water closets shall be made with an approved extension nipple or horn adaptor. The water closet shall be bolted to the hanger with corrosion-resistant bolts or screws. Joints shall be sealed with an approved elastomeric gasket, flange-to-fixture connection complying with ASME A112.4.3 or an approved setting compound.
- - - - - (Jerry's Comment: "The flange shall be ... and anchored to the structure" - that is a part often not done. The adapter for the PVC floor flange needs to be listed for that use, needs to be "The flange shall be attached to the drain" and needs to be "The flange shall be ... and anchored to the structure.")
- - - - 405.4.1 Floor flanges.
- - - - - Floor flanges for water closets or similar fixtures shall be not less than 0.125 inch (3.2 mm) thick for brass, 0.25 inch (6.4 mm) thick for plastic and 0.25 inch (6.4 mm) thick and not less than a 2-inch (51 mm) caulking depth for cast iron or galvanized malleable iron.
- - - - - Floor flanges of hard lead shall weigh not less than 1 pound, 9 ounces (0.7 kg) and shall be composed of lead alloy with not less than 7.75-percent antimony by weight. Closet screws and bolts shall be of brass. Flanges shall be secured to the building structure with corrosion-resistant screws or bolts.
- - - - - (Jerry's Comment: Another reminder that "Flanges shall be secured to the building structure" - and then specifying that "with corrosion-resistant screws or bolts" are used as one does not want the bolts to rust off.)
- - - - - 405.4.2 Securing floor outlet fixtures.
- - - - - - Floor outlet fixtures shall be secured to the floor or floor flanges by screws or bolts of corrosion-resistant material.
- - - - - (Jerry's Comment: "Floor outlet fixtures shall be secured to the floor or floor flanges" ... and if using plastic floor flanges, verify that the fixtures are allowed to be secured to the floor flange, some plastic floor flanges come with metal reinforcing plates and the fixtures are allowed to be secured to the floor flange, other plastic flanges are not strong enough to secure a fixture to - and a reminder to use "by screws or bolts of corrosion-resistant material" as one does not want the bolts to rust off.)
- - (subsections not included)
- - 405.5 Water-tight joints.
- - - Joints formed where fixtures come in contact with walls or floors shall be sealed.
- - - - - (Jerry's Comment: The joints are supposed to be "Water-tight joints".)
- - (subsections not included)

A question: is the hole in the floor sealed around, tight to the drain pipe? That pipe needs to be sealed around for fireblocking, and have an approved firestopping system sealing the annular space around the pipe. When sealed properly for both, water will not go down around the drain pipe. Some ... many ... older condo buildings never had the holes in the floor sealed up for either fireblocking or firestopping.

While pointing out that the joints are to be water-tight, I also recognize that, eventually, nothing stays water-tight forever (the longer the better, but forever is a very long time), and thus your concern for water seepage/leakage is valid - however, plan on doing the installation correctly and no water leaking for a long time, then follow the Manufacturer's Installation Instructions (MII). If the MII does not show or address installing around a drain pipe for a floor mounted toilet, email the manufacturer and have them send you the information and procedure to follow - you want it to be their issue, not yours.

Removing cast iron toilet flange and replacing with PVC, 4" that fits inside cast iron pipe.

How is the PVC floor flange secured to the cast iron drain pipe as required by "405.4 Floor and wall [u]drainage connections ... The flange shall be attached to the drain ... "?

[loubob]

The existing tile was very thin, and when you add the cork underlay and thicker tile for the new installation, the existing flange would be considered too low?

The existing flange is in good condition, but is not secured to the floor.

There is a gap between the pipe and the concrete floor. Place a filler rod down low and fill with reinforced concrete so that anchors can be attached to hold the flange?

Replace existing cast iron flange with Oatey 43538 ABS Cast Iron Flange Replacement, 4-Inch

Oatey 43538 ABS Cast Iron Flange Replacement, 4-Inch.jpg

Advise appreciated.

Thanks

Luis

[Jerry Peck - Codeman]

Is the cast iron encased in concrete (is the condo building constructed with concrete floors)?

If so, this ( https://www.oatey.com/ASSETS/DOCUMENTS/ ... cement.pdf ) seems like it would meet the requirements as it says "Flange slides easily into 4” cast iron piping with mechanical compression" and "Place the cast iron closet flange replacement into the pipe and tighten the stainless bolts using a hexagonal wrench. The rubber seal expands to seal against the interior of the pipe.", both of which create a method of attachment, which would meet this requirement (see underlining wording) - leaving you to meet the part in bold:

- - 405.4 Floor and wall drainage connections.
- - - Connections between the drain and floor outlet plumbing fixtures shall be made with a floor flange or a waste connector and sealing gasket. The waste connector and sealing gasket joint shall comply with the joint tightness test of ASME A112.4.3 and shall be installed in accordance with the manufacturer’s instructions. The flange shall be attached to the drain and anchored to the structure. Connections between the drain and wall-hung water closets shall be made with an approved extension nipple or horn adaptor. The water closet shall be bolted to the hanger with corrosion-resistant bolts or screws. Joints shall be sealed with an approved elastomeric gasket, flange-to-fixture connection complying with ASME A112.4.3 or an approved setting compound.

If that is in a floor and the cast iron is not encased in concrete (the cast iron could expand and break apart when the mechanical compression bolts are tightened, then that document says this "Consult Oatey Technical Department for applications not
specifically referenced above. " ... in which case you do what Oatey says to do - and get it in the form of printed published documentation for your protection and to support and backup why you did what you did (in case something doesn't work correctly).

"The existing flange is in good condition, but is not secured to the floor"

- That fits with what I said (see bold):
- - (Jerry's Comment: "The flange shall be ... and anchored to the structure" - that is a part often not done. The adapter for the PVC floor flange needs to be listed for that use, needs to be "The flange shall be attached to the drain" and needs to be "The flange shall be ... and anchored to the structure.")

The existing tile was very thin, and when you add the cork underlay and thicker tile for the new installation, the existing flange would be considered too low?

If you can find a sealing gasket which complies with the part in bold, then it might work - but that does not mean to do what is done quite often ... double up on the wax ring, with one of the wax rings being the type with the plastic 'funnel piece' molded into the wax ring ... I doubt that is an approved, listed connection, nor is it likely done in accordance with the manufacturer's installation instructions (find a proper seal for the existing floor flange, then you would need to secure the existing floor flange to the structure floor):
- - 405.4 Floor and wall drainage connections.
- - - Connections between the drain and floor outlet plumbing fixtures shall be made with a floor flange or a waste connector and sealing gasket. The waste connector and sealing gasket joint shall comply with the joint tightness test of ASME A112.4.3 and shall be installed in accordance with the manufacturer’s instructions. The flange shall be attached to the drain and anchored to the structure. Connections between the drain and wall-hung water closets shall be made with an approved extension nipple or horn adaptor. The water closet shall be bolted to the hanger with corrosion-resistant bolts or screws. Joints shall be sealed with an approved elastomeric gasket, flange-to-fixture connection complying with ASME A112.4.3 or an approved setting compound.