Do-it-yourself acrylic bath installation

Recommendation points

• Assembling the installation kit
• Bath insulation: why and how
• Installation and adjustment
• Fixing the sides
• Strengthening the bottom
• Side panels and abutment insulation

If the plumber doesn’t see the difference in the installation of acrylic and cast iron bathtubs, then this is not a real plumber. Fiberglass baths have very special qualities, so at each stage of their installation there are installation subtleties, which you will learn about from our detailed instructions for installing an acrylic bathtub with your own hands..

Assembling the installation kit

The bath must be turned upside down, which has a thickened pad in the center. Two mounting profiles must be placed on it so that all holes for attaching to the bath are no closer than 3 cm to the edge of the thickened section. Fastening is carried out only with self-tapping screws from the kit, if they are not there, refer to the instructions and check the permissible length of the fasteners, otherwise there is a chance to literally pierce the bowl through.

Studs must be inserted into the holes at the edges of the profiles and nuts and washers must be screwed on both sides. Rubber shock-absorbing nuts are screwed onto the upper edges of the studs until they stop. By adjusting the position of the nuts, you need to set the height of each leg relative to the support profile. It is equal to the difference between the height of the decorative screen and the passport height of the bowl, taking into account the profile and upper flange.

After adjusting, the nuts must be tightened well. The difference between large models of bathtubs may consist in a greater number of legs and profiles, and bathtubs with a seating position may even have an additional support system. But they all gather according to the same principle.

Turning the bowl over on its legs, you need to install a siphon and an overflow system. At the same time, the drain pipe is directed to the intended point of tapping into the drainage system and is completed with a corrugated PVC hose, resistant to high temperatures. If you have a mixer, assemble and install it, as well as screw on the flexible pipes for connecting to the water supply.

Bath insulation: why and how

A fiberglass bath conducts heat only slightly worse than a cast iron bath. Nevertheless, water cools quickly enough through the walls and bottom, and this is the main way of heat outflow. To improve the thermal insulation of the bowl, it is covered with a layer of polyurethane foam.

First, you need to thoroughly wipe and moisten the back of the bowl with a wet rag. The foam is first applied along the edge of the flange, then rises to the bottom of the bath in thin (2-3 cm) strips. You need to apply foam as quickly as possible so that the previous layer is still sticky and adheres well to fresh foam..

The bottom of the bowl and the profiles are covered with a layer twice as thick. To save foam, it is recommended to glue the bottom areas free of profiles with expanded polystyrene plates, and then cover them with a thin layer of foam.

Insulation is highly recommended, but not required. It makes sense to abandon foam coverage if you plan to equip a small niche under the bathroom and every inch of space is important. Although in such cases, insulation of even individual parts of the bowl still makes sense.

Installation and adjustment

The place for installing the bathtub should be in a state when the floor and walls are tiled, it is allowed to skip laying the tiles under the bathroom. Another option is to install the bathtub before tiling, or to fit it to the lowered edge of the tile. This option provides for the drainage of water from the walls into the bath, and not under it, however, the shape of the side for such an installation must be appropriate.

When placing the bowl in place, additional adjustment may be required. There are two reasons for this: the need to align the bathtub at the seams of the tiles or the shaking of the bowl on four legs. The adjustment is simple: unscrew the upper nut and tighten the lower one, periodically checking with the rack level and slightly rocking the bath. After that, holding the pin by the rubber knob, you need to tighten the upper nut, while the lower one will not turn in any way.

Remember also that you do not need to artificially create a slope to the drain hole, this is already incorporated into the design.

Fixing the sides

The sides of the bathtub touching the walls need additional fixing. This is done to compensate for lateral swaying under the weight of a person and so that the bath does not move itself from linear expansion when heated.

A mark is applied to the wall under the adjoining board, a line must be drawn from it along the perimeter of the installation and a steel corner or a rail made of solid wood must be installed along it. You can fix the support contour with quick-assembly dowels with a size of at least 8×80 mm every 50 cm.If an error was made when fixing the support rail, the legs may need to be adjusted again.

Before installing the bathtub completely, you should bend several L-shaped “legs” from the steel strip and try them on to the support rail, so that in the pressed state the folded edge is 2-3 mm from the tile or wall. These plates are installed every 50 cm, they are designed to firmly press the bath rim against the wall. If desired, they can be installed under the dowels for fastening the support rail, but in this case, a wide washer should be placed under the head.

When everything is ready for fixing the sides, the bathtub is installed 20-30 cm from the wall, connected to the sewerage and water supply system. On the boards adjacent to the walls, you need to apply sanitary sealant and, raising the far edge, hook the board on the fasteners on the rail. Immediately after this, the bath is filled with water to the maximum and left so for a day..

Strengthening the bottom

The value of the support legs is purely nominal, and the bath has a significant load on them. Fiberglass is a fairly resilient material, it is susceptible to sagging and bending, so the gap between the floor and the bottom of the bath should be filled with an incompressible material.

Several bricks should be laid directly on the floor and tied with a small amount of cement mortar. The masonry rises as close to the bottom as possible, the remaining gap is filled with polyurethane foam after the mortar dries. At the same time, the bath should be half filled with water so that the light bowl does not rise with expanded foam..

Additionally, the contact points of the brick with the flooring are foamed so that it does not move and the masonry does not expand. For low-set bathtubs and pallets, the brick can also be replaced with expanded polystyrene, several layers of which are glued together with polyurethane foam.

Side panels and abutment insulation

Most acrylic bathtubs have suitable decorative screens – if not included, then at an additional cost. For self-installation, this method is optimal due to its simplicity, besides, access to faulty plumbing can be obtained relatively harmlessly.

The screen mounting process is very simple. First, clips are attached under the side of the bowl, usually an adhesive connection is preferred in these places. Then the upper guide profile is attached to the clips. If the bath screen is curved, fastening with clips is performed every 15-20 cm.

Using a plumb line, the extreme line of the profile is transferred to the floor, where, after preliminary marking, the lower guides are installed and fixed with dowels. The shape of the profiles may differ depending on whether you have chosen a solid screen or with hinged doors. If you need to provide access, for example, to the siphon through a blank screen – nothing prevents you from cutting a rectangular opening in the flat part and fixing a light revision door in it on liquid nails.