How To Install a Shower Pan

Apr 22 2022

Before Installing your HYDRO-BLOK Shower System

Ensure all parts of the Brass drain kit are present.
a) Solid brass caulking nut with tightening insert key
b) Rubber caulking casket
c) Solid brass drain body
d) Rubber and fiber gaskets
e) Solid brass locking nut

If the top edge of the shower pan is higher than the floor plate 2″ x 4″, another 2” x 4” must be installed on top of the existing floor plate
between each wall stud. This provides the wallboard with the necessary support needed at the shower pan joint.

The subfloor must be solid, level and properly constructed to meet deflection standards. For wood floors, joists must be 16″ OC with ¾” T & G plywood or equivalent glued and screwed.

The drain pipe must be securely fastened below the subfloor so that it will not move under load. The drain should be centered through a 5″ round opening in the subfloor to allow the proper fit of the drain assembly. Cut the 2″ ABS or PVC drain pipe ⅛” higher than the subfloor. Clean off any burrs on the 2″ pipe after cutting.

Perform a final floor and wall measurement check to ensure all walls are square and make any adjustments required BEFORE installing your HYDRO-BLOK shower system. Clean the shower pan install area of any dirt, dust or debris.

Installation Tools and Materials Required

• 5 Gallon plastic bucket and drill with mixing paddle
• Modified thinset
• #2 Robertson or #2 Philips screwdriver drill bit
• Large flat head screwdriver
• Professional notch trowel (minimum ⅜” x ⅜” square notch)
• 7 ¼” Circular saw and hand saw with small teeth
• Tape measure & fine point marker
• Level
• Utility knife
• 4′ to 6′ Straight edge or similar square
• Cleaning supplies (we recommend paper towels, citrus wipes, rags, dust pan and brush)

Included in your HYDRO-BLOK Shower Pan box are

• 2″ Wide mesh tape (for final shower pan joint)
• Straight and corner putty knives
• Brass drain kit

step 1

Step 1 – Install the Shower Pan and Drain Kit

Install the Shower Pan and Drain Kit. Measure the area where the shower pan will be installed to determine if the pan must be cut to size. Pay attention to the drain location when cutting a shower pan to size. We recommend leaving a ⅛” space between the pan edge and the framed wall.

step 2

Step 2 – Dry fit the shower pan on the subfloor

Dry fit the shower pan on the subfloor and ensure that the subfloor opening and drain pipe are centered inside your shower pan drain opening. Ensure all sides of the shower pan fit comfortably to the walls. DO NOT try to force the shower pan into its location.

step 3

Step 3

Apply a continuous ¼” bead of HYDRO-BLOK Joint Sealant around the top edge of the first notch inside the shower drain profile ensuring that the bead is consistent and full. Drop the solid brass drain body into the joint sealant and seat it firmly

step 4

Step 4 – Place the shower pan on edge

Carefully place the shower pan on edge and slide the rubber gasket and then the fiber gasket over the drain body threads while firmly holding the drain body from the front to ensure it remains seated in the shower pan.

step 5

Step 5

Thread the solid brass locking nut onto the drain body while continuing to hold the drain body from the front. Hand tighten the nut until the gaskets are snug against the stainless steel support ring on the underside of the shower pan. Once snug, check the positioning of the drain body to ensure it is in the proper position. Continue to tighten to a firm tension (do not use tools to tighten!). Use a paper towel or citrus wipes to wipe away excess sealant from the edge of the solid brass drain body on the top of the shower pan.

step 6

Step 6 – Mix modifed thinset as per manufacturer’s instructions

Mix modifed thinset as per manufacturer’s instructions. Apply thinset to the subfloor starting at the back of the shower area, troweling towards the front. Ensure the trowel lines are pointing to the front or curb of your shower pan. This will ensure there will be no voids in the installation. DO NOT cross channel trowel lines or air can not escape.

step 7

Step 7 – Apply thinset to the back of  shower pan

Apply thinset to the back of your shower pan using the smooth side of a trowel. Do not apply thinset on or within ½” of the stainless steel drain support ring. Carefully place the shower pan in the proper position on the subfloor and press into place by walking on the shower pan. Ensure the shower pan is firmly pressed into the thinset mortar and is level on all 4 sides. Use a level to check the slopes to the drain. Wipe away any thinset which may have accumulated on the drain pipe.

step 8

Step 8 – Slide the rubber caulking gasket

Slide the rubber caulking gasket (bevel side up) over the 2″ drain pipe until it is flush with the top of your drain pipe. Ensure that the rubber gasket is not higher than the top of the 2″ drain pipe. Soapy water may be used to help ease the rubber gasket onto the pipe. DO NOT use a petroleum based lubricant.

step 9

Step 9 – Attach the Drain Body

Thread the solid brass caulking nut into the drain body to compress the rubber gasket onto the 2″ drain pipe. Once it is hand tight, take the flat tightening key and place it into the solid brass caulking nut and then further tighten with a large flat screwdriver by placing the screwdriver in the slit in the middle of the tightening key.

step 10

Step 10 – Position the Shower Pan

The wallboard at the rear of the shower should be installed first. Begin installing your wallboard by apply a ½” continuous bead of HYDRO-BLOK Joint Sealant inside the channel created by the shower pan and the wall plate. Place your pre-cut, ½” thick wall board into the channel and firmly press it into place, using a level to ensure the board is properly positioned.

TIP: Rear wallboard surface should be the full width of the shower pan.

step 11

Step 11 – Position and Level the Shower Pan

Fasten the wallboard to the studs using HYDRO-BLOK screws and washers. Place the first washer 12″ up from the bottom of the shower pan and screw it in flush to the surface of the wallboard. Continue placing washers and screws every 12″ along each stud until the entire sheet is fastened to each stud.

Use the HYDRO-BLOK corner puttyy knife to smooth out the excess joint sealant from the seam between the shower pan and the wallboard (excess joint sealant can be used in the following steps to cover washers and screws).

step 12

Step 12 – Install a washer screw

When placing a new piece of wallboard on top of an existing one, apply a ½” bead of joint sealant along the entire edge of the lower board. Press the new wallboard firmly into the joint sealant and hold against the studs. Install a washer and screw 12″ up from the seam close to the to center of the board to provide initial support.

step 13

Step 13 – Smooth out the excess joint sealant

Install washers and screws along the seam before continuing to add washers and screws at 12″ intervals to secure the board to the studs. Use a HYDRO-BLOK standard putty knife to smooth out the excess joint sealant along the seam, using it to cover the seam as well as the screws and washers.

step 14

Step 14 – Install side wallboard

Apply a ½” continuous bead of joint sealant in the side shower pan channel and down the edge of the rear wall board so that the side wallboard can be pressed firmly into the shower pan channel and against the rear wallboard. Place pre-cut side wallboard approx. 1″ from the rear wallboard and press it firmly into the shower pan channel. Once in place, begin to push it towards the rear wall board and press firmly into the vertical line of joint sealant. Ensure the wall board is firmly and equally in the shower pan channel using a level.

step 15

Step 15 – Attach the wallboard to the studs with washers and screws

Attach the wallboard to the studs with washers and screws using the same method as was used for the rear wallboard. Use the corner putty knife to smooth out the excess joint sealant from the seam between the shower pan and the wallboard (excess joint sealant can be used in the following steps to cover washers and screws).

step 16

Step 16 – Install the shower shower curb

Once all wallboard is in place, apply a final bead of ½” joint sealant on all wallboard joints, seams and washers to complete installation. Use a HYDRO-BLOK corner putty knife for all 90 degree seams and the standard putty knife for all flat seams and washers. Ensure there is at least 1″ of joint sealant on either side of any seam. DO NOT apply additional joint sealant to finish the seam between the wallboard and shower pan until the shower curb has been installed.

step 17

Step 17 – installing the HYDRO-BLOK Shower Curb

Begin installing the HYDRO-BLOK Shower Curb by cutting the shower curb ⅛” shorter than the distance between the two shower walls where the curb will be placed. If your shower requires curbs on two sides of the shower pan see the Installation Tips on the back page of this guide. Apply a ½” continuous bead of joint sealant along the shower pan notch as well as the exposed foam edge of the shower pan. Apply a generous amount of joint sealant to the wallboard where the ends of the shower curb will be located.

step 18

Step 18 – Apply thinset

Trowel thinset out from the shower pan edge to the edge of the curb location. Trowel away from the pan in one direction. Apply thinset on the underside of the shower curb with the smooth edge of the trowel. Ensure the thinset does not contact or mix with the joint sealant, cleaning off any excess thinset from the joints of the shower curb.

TIP: Perform a final check to ensure the thinset has not come in contact with any joint sealant as this will contaminate the joint. Fix any areas where this may have happened by removing the excess thinset from any foam areas and re-applying the joint sealant.

step 19

Step 19 – Install shower curb

Position the shower curb ensuring the curb is firmly pressed into place against the shower pan notch and the thinset on the sub floor.

We recommend placing the curb from the top down at a slight angle to avoid the thinset from contacting or mixing with the joint sealant.

TIP: We recommend placing weight on the curb while applying joint sealant in the following steps.

step 20

Step 20 – Anchor the Shower Pan

Apply a continuous ½” bead of joint sealant into the corner seam of the shower pan where it meets the curb or wallboard. Use the corner putty knife to smooth out the sealant so that there is at least 1″ of sealant on either side of the seams.

Press 2″ mesh tape (supplied) into the seam, pressing it into the existing joint sealant. Use a sharp utility knife to make small slits to fit the corners. Use a corner putty knife to smooth the mesh tape into the joint sealant. Apply a continuous ½” bead of joint sealant on top of the mesh tape and smooth out again with the corner putty knife to fully cover the mesh tape.

step 21

Step 21 – Repeat Step 20

Repeat Step 20 for all seams between the wallboard and the shower curb.

Important: The mesh strips must be long enough to go from the shower pan base to the front of the curb where it meets the sub floor. Mesh tape should always be pressed into joint sealant and should not make any contact with the cement surface of the wallboard, pan, or curb. It should always be fully covered by the final application of joint sealant.

step 22

Step 22 – Final check of all joints and screws

Perform a final check of all joints and screws/washers to ensure they are completely covered in joint sealant. Check the caulking nut on the drain assembly again to ensure it is tight and cannot be turned by hand with a screwdriver.

A’er approximately one hour, (at room temperature of at least 18° C or 65° F) the joint sealant will skin over and thinset can safely be applied. The drain assembly and shower pan can be water tested to confirm a leak free installation using a 2″ drain plug

step 23

Step 23 – Complete the Drain Hookup

Loosely fit the HYDRO-BLOK stainless steel drain and tray into the shower pan drain opening while installing tile (tile up to the edge of the tray).

DO NOT glue the tray into the opening. Should the drain cover need to be raised to accommodate thicker format tile/stone, cut the supplied plastic riser to adjust the height of the drain cover.

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