Cutting a Roll-In Shower Back Wall Panel to Route Supply Lines or Clear a Valve

Yes, the wall panels of the multi-piece gel coat roll-in showers can be cut on site to route water supply lines or to clear an existing valve, and installers do this regularly. The panels are made of wood and fiberglass with steel reinforcing rod, or rebar, running around the perimeter, so the job takes two kinds of blade: a jig saw or a fine-blade circular saw for the panel itself, and a reciprocating saw fitted with a steel-cutting blade for any rebar in the path. Before you cut through a reinforcing rod, check with the team, because whether a given rod can be cut depends on where it sits in that unit.

How the Panels Are Built

Each gel coat wall panel has a smooth gel coat finish facing the shower, with wood and fiberglass behind it. Steel rebar is embedded around the perimeter of the panel, and on some back wall panels a rod also runs through the center. The wood and fiberglass cut cleanly with ordinary woodworking tools. The rebar does not, and it needs a metal-cutting blade, so find out where the steel is before you start.

Cutting the Opening

1. Dry-fit the unit in the alcove and mark exactly where the supply lines, valve or shower arm need to pass through the back wall. Layout for the whole unit is covered in installing multi-piece gel coat showers.
2. Check the marked area for rebar from the back of the panel. If the cut lands on the perimeter rod or a center rod, stop and send a photo of the location with your model number to the team before going further.
3. Cut the panel with a jig saw or a fine-blade circular saw, keeping the blade moving steadily so the gel coat edge stays clean.
4. Where a rod has been confirmed as safe to cut, switch to a reciprocating saw with a steel-cutting blade and cut the rod separately from the panel material.
5. Use proper safety gear throughout, including eye protection, and support the panel so it cannot flex against the blade.

Why the Rebar Question Matters

The reinforcing rod keeps a large panel flat and rigid, so it should not be cut casually. That said, cutting is often possible. In one installation the contractor needed to keep an existing valve at its height to stay within accessibility guidelines, and cutting the rod at the center of the back wall was the only way to avoid relocating the valve. The team confirmed with the manufacturer that the rod could be cut in that area and the install went ahead. Each confirmation is specific to the unit and the spot, which is why a quick photo to support before the cut is worth the short wait.

Routing Supply Lines Behind the Wall

Supply lines that enter behind the back wall on one side and leave the enclosure on the other need to be planned before the unit goes in. Where the lines must pass through the panel, cut the opening at the marked location rather than notching the panel's edge, since the perimeter rod runs there. Your plumber can confirm the routing against the dry-fit unit before any cut is made.

Valve, Shower Head and Related Fitting Work

Valve choice and the standard valve and shower-head openings are covered in choosing a shower valve and cutting the openings. For wall kits, surrounds and tiles, see the wall kit, surround and tile installation guide. Once the unit is in, caring for gel coat units and bases covers day-to-day upkeep.

Common Questions

Still Need Help?

Open a ticket at ellasbubbles.com/support or call (800) 480-6850 and have your model and serial number ready.