Introduction
The installation of an aquatic bathtub, particularly an acrylic model such as the Kohler Archer Bathtub, requires meticulous attention to structural integrity, alignment, and sealing. This guide draws from two primary sources: an official installation manual from a manufacturer and a detailed step-by-step tutorial from a user-led installation project. These documents provide insights into subfloor preparation, framing, adhesive application, and securing the tub to the wall studs.
The installation process is structured to ensure that the tub remains level, stable, and properly sealed against water infiltration. Special emphasis is placed on reinforcing the subfloor, building support walls, and using specific tools such as an impact driver, framing nailer, and liquid nails adhesive. The Kohler Archer model also requires a specialized overflow kit for proper drainage.
This article outlines the full installation procedure, with a focus on actionable, replicable steps. It is intended for U.S. consumers, DIY enthusiasts, and professionals seeking a reliable reference for acrylic bathtub installation.
Subfloor Preparation and Framing
Before placing the bathtub, the existing subfloor must be removed and replaced with a stable base. In older homes, especially those with water damage or uneven flooring, this is a critical step. The process involves removing the old subfloor using a hammer or a super bar, followed by extracting nails and debris.
Once the old subfloor is removed, a new 1/2-inch plywood layer is added. Liquid nails construction adhesive is applied between the layers to strengthen the bond. This step is particularly important in ensuring the subfloor can support the weight of the bathtub and water.
A framing nailer is used to secure the new subfloor to the underlying joists and the first layer of plywood. This reinforces the structure and prevents sagging or movement during the installation of the bathtub.
After the subfloor is prepared, the bathtub is dry-fitted to mark its position. This is especially important in older homes where walls may not be perfectly plumb or square. The tub is centered on the plumbing wall and aligned with adjacent walls to ensure a balanced installation.
Framing the Support Walls
The installation of an acrylic bathtub often requires the construction of support walls to provide additional stability. These include a main wall and a knee wall (also known as a pony wall). The main wall supports the primary side of the tub, while the knee wall supports the front or back depending on the tub’s orientation.
Studs are added to the plumbing wall to align with the tub’s dimensions. A level is used to check for plumbness, ensuring that the framing will support the tub evenly. Once the framing is in place, the tub is positioned again to verify alignment and make any necessary adjustments to the wall structure.
Cutting for Drainage and Overflow
A critical step in the installation is preparing the subfloor for the bathtub’s drain and overflow system. The drain requires an elliptical cut in the subfloor, which can be made using a jigsaw or reciprocating saw. This step can be complicated in older homes where joists may be uneven or positioned below the drain location.
The Kohler Archer Bathtub requires a special overflow kit, which must be assembled correctly to ensure proper function. This overflow system is part of the tub’s design and contributes to its aesthetic appeal. The overflow must be aligned with the cut in the subfloor and secured in place before the tub is lowered into position.
Securing the Bathtub
Once the subfloor and framing are prepared, the bathtub is lowered into the prepared space. Liquid nails adhesive is applied to the subfloor, and the tub is pressed into the mortar to ensure a firm bond. It is crucial to check for level in multiple directions—along the main wall, front, and back.
Pre-drilling holes in the tub’s lip allows for the attachment of screws into the wall studs. A 4-foot level is used repeatedly to verify alignment. Once the tub is level, 2-inch galvanized screws are used to secure it to the studs. A foot is placed on the inside edge of the tub to hold it steady during this process.
If there are gaps between the tub flange and the studs, shims are inserted to prevent the tub lip from cracking when the screws are tightened. This step is essential in older homes with uneven framing or subflooring.
Finalizing the Installation
After the tub is secured, the final steps include sealing and caulking. A caulking gun is used with 100% silicone sealant to create a watertight barrier between the tub and the surrounding walls. This prevents water from seeping into the subfloor or framing.
Additional adhesive may be applied around the tub’s edges to reinforce the seal. A level is used one final time to ensure the tub remains even after all adjustments and attachments have been made.
The installation concludes with a walkthrough of the tub to check for stability, alignment, and sealing. If any adjustments are needed, they are made before the final cleaning and use of the tub.
Conclusion
The installation of an aquatic bathtub, particularly an acrylic model such as the Kohler Archer, requires careful planning and execution. The process begins with subfloor preparation and framing, followed by precise cutting for the drain and overflow. The tub is then lowered into place, secured with screws, and sealed to prevent water damage.
The use of specialized tools such as a framing nailer, impact driver, and jigsaw is essential for a successful installation. The Kohler Archer model’s unique overflow system requires additional attention to ensure proper function.
By following a structured, step-by-step process and using the correct materials, the bathtub can be installed safely and effectively. This guide provides a comprehensive overview based on verified installation methods from manufacturer and user-led sources.