Building a Custom Seat or Bench

Custom Shower Seats and Benches made from wedi® Building Panels 

wedi offers prefabricated seats and benches, which can be quickly integrated into a shower system installation. However, if a custom size is required for the seat or bench, you can also use our 2-inch thick wedi® Building Panel to safely build one on site. Possible designs include suspended wall-mounted corner seats, and benches that rest on the shower floor.

wedi® Building Panels allow you to build a seat or bench in a fraction of the time it takes to conventionally frame out a support, cover it with plywood and backer board, and then waterproof it. With wedi® Building Panel all this is combined in one product that is shaped, installed, and ready for tile. This process also allows the tile setter to build the seat or bench to fit the exact final dimensions that are ideal for the individual tile layout and design.

wedi® Shower Benches, whether prefabricated out of the box or built onsite, are made to withstand the weight of tile and users. Based on the model and design, the load capability before tiling ranges between 250 and 500 lbs:

  • On-site custom wall-mounted corner seats: 250 lbs.
  • Prefabricated wall-mounted corner seats: 350 lbs
  • Seats and benches resting on the floor/attached to shower walls: 500+ lbs
Ghost Accordion

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Custom Bench Fabrication and Installation Videos
Installation Manual and Requirements/Limitations
Product Approvals & Certification

Approvals and certificates applicable to entire Fundo Shower System incl. wedi Building Panel:

City of New York, MEA 912-52-SM

Fundo Shower Systems & Building Panels: ICC PMG 1189 (for USA & Canada) – Download Here

Meets all applicable ANSI/ISO Standards incl. ANSI 118.10 and IAPMO PS106

TCNA handbook recognized for wall, floor, countertop, & more applications

City of Los Angeles Approval M-100017

BBA (British Board of Agrement)


CE Marked

Diverse State Approvals

SAI Global Watermark Certified (Australia & New Zealand)

Codemark Certified (Australia & New Zealand)

Technical Performance Data

ASTM C 578
Standard Specification for Rigid, Cellular Polystyrene
Thermal Conductivity
75°F (25°C) - ASTM C518
0.23 Bbtu in/hr F
75°F (25°) - ASTM C518
4.3hr ft. 2 F/Btu/in (R Value for 1” wedi = 4.3)
Tensile Strength
65 psi
Shear Strength
Under conditions required in ANSI A118.10-1999
4 week Shear Strength Dry: 216 psi 12 week Shear Strength Dry: 217 psi 100 day Shear Strength Wet: 201 psi
Flexural Strength
627 PSI
ASTM D4068 / ANSI A118.10-1999
Fungus/Bacteria Resistance
Passed, No Growth
Linear Variation
AC 159/ASTM 1037-39
Passed, less than 0.07%
Seam Strength
ASTM D751-11 (requirement 8 lb/in width)
Passed, 36.4 lbs
Robinson Floor Test
Heavy duty commercial use, passed
Fastener Pull Through
Wet 131.8 lb./Dry 196.2 lb.
Temperature Limits
-58 / +165° F
Freeze & Thaw
ASTM C666 - 25 Cycles
No disintegration/change; Passed
Accelerated Aging
AC 71 - 25 Cycles
No disintegration; Passed
Surface Burning Characteristics
ASTM E84-16 (NFPA 255, ANSI / UL 723, UBC 8-1) Tested as required without tile on Building Panel surface
Flame Spread Index (FSI): 20 | Smoke Developed Index (SDI) : 70 |Classification: Class A

Product Sizes

To determine the size and quantity of wedi Building Panels you will need for your shower, please follow the steps outlined below: 

  1. Calculate the total area of the shower wall
    1. Multiply L x H of the wall. The height of each wall will be determined based on how high you plan to install the tile
    2.  Add the calculated square footage of each wall together to determine the combined sum of all the shower walls
    3. Multiply the combined area of all shower walls by 1.15 to account for about 15% extra square feet of building panel for any waste cuts
  2. Divide the total area of the shower walls by the square foot area of the wedi building panels you plan to us4 (e.g. 4×5 ft. building panel = 20 square feet)
    1. A total shower wall area of 115 square feet divided by 20 square feet per building panel gives us a total of 5.75 building panels.
    2. Remember to always round up to the next whole building panel.


For product retail pricing, please see our Illustrated Retail Price List (USA or CA), available in the downloads section below.

Main application
Item Number
Constructing benches, floors to line up with Fundo Shower Bases into bathroom
48 in. x 60 in. x 1 1/2 in.
2 sheets/box
Constructing benches and suspended seats, freestanding walls and partitions
48 in. x 60 in. x 2 in.
2 sheets/box
Constructing benches and suspended seats, freestanding walls and partitions
48 in. x 96 in. x 2 in.
12 sheets/pallet

Step 2 Complete!

You’ve chosen your building panels, now choose your prefabricated modules!

Additional Downloads