Before Installing Your HydroBlok™ Shower System

Verify Brass Drain Kit Contents

Ensure all parts of the brass drain kit are present:

• Solid brass caulking nut with tightening insert key

• Rubber caulking gasket

• Solid brass drain body

• Rubber and fiber gaskets

• Solid brass locking nut

Framing & Backing

• If the top edge of the shower pan is higher than the floor plate (2"×4"), add another 2"×4" on top of the existing plate between each wall stud to support the pan-to-wallboard joint.

Subfloor Requirements

• Subfloor must be solid, level, and meet deflection standards.

• Wood floors: joists 16" O.C. with 3/4" T&G plywood (or equivalent), glued and screwed.

Drain Pipe Prep

• Secure the drain pipe below the subfloor so it cannot move under load.

• Center the drain through a 5" round opening in the subfloor.

• Cut the 2" ABS or PVC drain pipe 1/8" higher than the subfloor; deburr after cutting.

Final Checks

• Confirm walls are square; make adjustments before installation.

• Clean the pan install area of any dirt, dust, or debris.

Installation Tools & Materials (Required)

• 5-gallon bucket & drill with mixing paddle

• Modified thinset

• #2 Robertson or #2 Phillips screwdriver bit

• Large flat-head screwdriver

• Professional notch trowel (min. 3/8" × 3/8" square notch)

• 7-1/4" circular saw & small-tooth hand saw

• Tape measure & fine-point marker

• Level

• Utility knife

• 4'–6' straightedge or square

• Cleaning supplies (paper towels, citrus wipes, rags, dustpan, brush)

Included in Your HydroBlok™ Shower Pan Box

• 2" wide mesh tape (for final pan joint)

• Straight and corner putty knives

• Brass drain kit

Installation Steps

Step 1 — Install the Shower Pan & Drain Kit

Measure the install area. If cutting the pan, account for the drain location and leave a 1/8" gap between pan edge and framed wall.

Step 2 — Dry-Fit the Pan

Dry-fit on the subfloor; ensure the subfloor opening and drain pipe are centered in the pan’s drain opening. The pan should fit comfortably—do not force.

Step 3 — Set the Drain Body in Sealant

Apply a continuous 1/4" bead of HydroBlok™ Joint Sealant around the top edge of the first notch inside the drain profile. Drop in the solid brass drain body and seat firmly.

Step 4 — Gaskets on the Backside

With the pan on edge, slide the rubber gasket and then the fiber gasket over the drain body threads while holding the drain body in place from the front.

Step 5 — Locking Nut

Thread the solid brass locking nut onto the drain body while holding the front. Hand-tighten until the gaskets seat snugly against the underside stainless support ring. Check alignment; tighten to firm tension by hand only. Wipe excess sealant on the pan surface.

Step 6 — Thinset on Subfloor

Mix modified thinset per manufacturer. Trowel from the back towards the front of the shower area with lines pointing to the curb/front. Do not cross-channel; allow air to escape.

Step 7 — Butter the Pan Back

Key thinset onto the back of the pan with the smooth side of the trowel. Do not place thinset on or within 1/2" of the stainless drain support ring. Set the pan, walk it in, check level on all four sides and slope to drain. Clean thinset off the drain pipe.

Step 8 — Rubber Caulking Gasket on Pipe

Slide the rubber caulking gasket (bevel up) over the 2" pipe until flush with the pipe top. It must not sit higher than the pipe top. Use soapy water if needed (no petroleum lubricants).

Step 9 — Caulking Nut

Thread the solid brass caulking nut into the drain body to compress the gasket onto the 2" pipe. Hand-tighten, then insert the tightening key and use a large flat screwdriver in the key’s slot to further tighten.

Step 10 — Rear Wallboard: Bed in Sealant

Apply a 1/2" continuous bead of Hydroblok™ Joint Sealant inside the channel formed by the pan and wall plate. Place pre-cut 1/2" wallboard into the channel, press firmly, and level.

Tip: The rear wallboard should span the full width of the shower pan.

Step 11 — Fasten Rear Wallboard

Fasten with Hydroblok™ screws & washers: first washer 12" up from the pan, then every 12" along each stud. Smooth excess sealant at the pan-to-board seam with the corner putty knife (reuse excess to cover washers/screws).

Step 12 — Stacking Boards

When placing a new board above an existing one, run a 1/2" bead of sealant along the top edge of the lower board. Press the new board in, then add one washer/screw 12" above the seam near the top-center for initial hold.

Step 13 — Secure & Tool the Seam

Install washers/screws along the seam studs, then at 12" intervals. Tool excess sealant over the seam, screws, and washers with a standard putty knife.

Step 14 — Side Wallboard: Bed & Set

Apply a 1/2" bead of sealant in the side pan channel and down the rear board edge. Place the pre-cut side board about 1" from the rear board, press into the channel, then slide toward the rear to engage the vertical bead. Level and ensure equal seating in the channel.

Step 15 — Fasten Side Wallboard

Fasten to studs as per the rear board. Tool excess sealant at the pan-to-board seam (reuse to cover washers/screws).

Step 16 — Finish Joints (Pre-Curb)

Once all wallboard is in place, run a final 1/2" bead of sealant on all wallboard joints, seams, and over washers. Tool with corner knife for 90° seams and standard knife for flats. Ensure ≥1" of sealant coverage on each side of every seam.
Do not finish the wallboard-to-pan seam until the shower curb is installed.

Step 17 — Prepare the HydroBlok™ Shower Curb

Cut the curb 1/8" shorter than the distance between the walls it spans. If curbs are needed on two sides, follow the curb tips in the full guide. Apply a 1/2" continuous bead of sealant along the pan notch and exposed foam edge, and a generous bead on the wallboard where curb ends will land.

Step 18 — Thinset for the Curb

Trowel thinset from the pan edge out to the curb location in one direction. Butter the underside of the curb with thinset (smooth edge). Do not let thinset contact or mix with joint sealant; clean any contamination immediately and re-apply sealant where needed.

Step 19 — Set the Curb

Place the curb from the top down at a slight angle to avoid thinset touching the sealant. Press firmly into the pan notch and thinset on the subfloor.
Tip: Place weight on the curb while applying sealant in the next steps.

Step 20 — Anchor Pan-to-Curb/Board Seams

Run a continuous 1/2" bead of sealant in the corner seam(s) where the pan meets the curb or wallboard. Tool with a corner putty knife to achieve ≥1" coverage on both sides.
Press 2" mesh tape into the wet sealant (cut small relief slits at corners if needed), smooth in, then apply another 1/2" bead over the tape and tool until fully covered.

Step 21 — Repeat for All Pan-to-Board/Curb Seams

Repeat the previous step for every seam between the wallboard and the shower curb.
Important: Mesh strips must run from the pan base to the front of the curb at the subfloor. Mesh must be embedded only in sealant—never directly on cement surfaces—and fully covered by the final sealant layer.

Step 22 — Final Coverage & Tightness Check

Confirm all joints, screws, and washers are completely covered in sealant. Check the caulking nut on the drain; it should be tight and not turn by hand (even when using a screwdriver in the key).

After ~1 hour at ≥18°C / 65°F, the sealant will skin over and thinset can be applied. The drain assembly and pan can be water-tested using a 2" drain plug.

Step 23 — Complete the Drain Hookup

Loosely fit the HydroBlok™ stainless drain and tray into the pan opening while tiling (tile up to the tray’s edge).
Do not glue the tray. If you need extra height for thicker tile/stone, cut the supplied plastic riser to raise the drain cover accordingly.