Schluter®-KERDI-DRAIN-A adaptor kits are used to convert clamping ring drains…
…to integrated bonding flange drains when removal of the clamping ring drain is not
practical. There are two kit sizes available…5 ¼”,
or KDA5 and 7 ½”, or KDA7. Let’s take a look at what’s inside each
of the kits. A
bonding flange designed to integrate with the adaptor ring is provided as well. It’s
important to recognize that the adaptor flanges are different from the standard KERDI-DRAIN
flanges sold separately and are not interchangeable. The kit also includes a height adjustment
collar for the KERDI-DRAIN grate. The KDA7 kit contains a 7 ½” diameter adaptor
ring (pause) and corresponding bonding flange. The kit also includes a lateral adjustment
ring which is provided for the KERDI-DRAIN grate.
The Grate Assembly is sold separately from the KERDI-DRAIN-A adaptor kit. Grate kits
include a drain grate, height adjustment collar, and lateral adjustment ring.
When using the KDA5, use the height adjustment collar from the adaptor kit only. The height
adjustment collar and lateral adjustment ring included with the grate kits are not compatible
with the KDA5. However, when using theKDA7, use the height
adjustment collar from the grate assembly in combination with the lateral adjustment
ring from the adaptor kit. The lateral adjustment ring included with the grate kits are not
compatible with the KDA7. The Tileable grate cannot be used with the
KERDI-DRAIN Adaptor flanges. The KERDI-DRAIN-A adaptor kits can be used
with either a mortar base or the Schluter®-KERDI-SHOWER prefabricated shower trays.
First, we’ll demonstrate installation of the KDA5. The process is the same for the
KDA7. Remove the clamping ring from the installed
drain. Be sure to save the bolts for the installation
of the adaptor ring. Align the bolt pattern of the clamping ring
with the matching punch-outs in the adaptor ring. The bolt patterns are designed to line
up with the majority of clamping ring drains. Punch the matching inserts out through the
adaptor ring. Apply a continuous one-quarter inch to three-eighths
inch bead of Schluter-KERDI-FIX to the underside of the adaptor ring or on the clamping ring
drain itself, making sure to encircle the bolt holes.
Align the holes in the adaptor ring with the bolt holes in the installed drain and place
the adaptor ring on the installed drain flange. Re-insert and tighten the bolts.
Bolts are to be finger-tight plus one quarter turn.
Use a crossing pattern to create even compression of the gasket.
Do not over tighten, as this may warp the adaptor ring and result in leaks.
The adaptor flange will be inserted into the adaptor ring and must sit flush with or slightly
below the surface of the KERDI-SHOWER tray. The bonding flange in the KDA7 has a relatively
long outlet in order to reach drains that are recessed into floors. In some cases, it
will be necessary to shorten the outlet to prevent the flange from sitting above the
shower tray. This can be done with a saw or rotary cutting tool.
Depending on the elevation of the installed clamping ring drain, it may be necessary to
raise the elevation of the substrate before installing the tray.
A polystyrene foam panel, tile backerboard, or other underlayment may be used for this
purpose. The required underlayment thickness can vary
with the installed drain elevation and shower tray thickness. For example, when using one
of the KERDI-SHOWER-TT thin tray options, a thicker underlayment may be necessary.
Make sure to measure and dry-fit components before installation.
In this video, installation of a polystyrene foam panel will be demonstrated.
Polystyrene foam is lightweight, easy-to-cut, and may be used over both plywood and concrete
substrates. Be sure not to use a moisture-sensitive underlayment
such as plywood in applications over concrete, particularly young concrete or concrete on
grade that is subject to moisture migration. Any leveling of the floor must be done prior
to the installation of the panel. Apply any of our Schluter thin set mortars…or
an unmodified thin-set mortar to the substrate using a one-quarter inch by three-eighths
inch square- or U-notched trowel. Place the foam panel and solidly embed in
the mortar. Using the same trowel, apply thin-set mortar
to the underlayment.
Place the KERDI-SHOWER tray and solidly embed in the mortar.
Next, we will install the bonding flange. Apply thin-set mortar to completely fill the
step in the shower tray. Press the adaptor flange firmly into the mortar
to ensure full support. Check the drain for level. Clean the excess
mortar from the top of the bonding flange to prepare for the KERDI collar installation.
Install the KERDI collar using any of our Schluter thin set mortars…or an unmodified
thin-set mortar. Apply the mortar with a ¼” x 3/16” V-notched
trowel or the Schluter®-KERDI-TROWEL, which features a 1/8” x 1/8” square notched
design. Using the flat side of the trowel apply thin-set
mortar over the bonding flange and within the recessed area of the shower tray surrounding
the drain. Then comb additional mortar using the notched side of the trowel.
Center the included KERDI collar, over the KERDI-DRAIN-A adaptor flange and embed using
the flat side of the trowel or a dry wall taping knife. Make sure this connection is
secure. Clean the excess mortar from the bonding flange.
The installation of the KDA5 and the prefabricated tray are now complete.
When installing KERDI-DRAIN-A with a mortar base, follow the same process for installing
the adaptor ring. Before installing the drain flange, place
a ring of loose mortar around the inlet hole in the floor.
Pay close attention to filling the area over the existing drain and adaptor ring.
Slide the adaptor flange into the adaptor ring and solidly embed the flange in the mortar
to ensure full support. Clean the excess mortar from the top of the
bonding flange. Check the drain for level and adjust as required. The mortar bed is
placed flush with the top of the bonding flange and work on the shower assembly may continue.
We have successfully converted the clamping ring drain to an integrated bonding flange
drain and can continue with the Schluter Shower System installation.
If you still have questions, please contact our Customer Support Specialists. For more
information on Schluter products, visit Schluter.com or check our YouTube channel to view our videos.