I have spent more than a decade fitting wet rooms and low-profile showers in older homes across the Midlands, where uneven floors are more common than straight ones. I usually work on compact bathrooms that need a practical layout without raising the floor too much. A Drybase shower tray can solve several installation problems, but only if I prepare the base carefully and treat every joint as part of the waterproofing system. The tray itself is rarely the difficult part.
I Start by Reading the Room, Not the Product Label
Before I bring a tray into the bathroom, I check the floor, waste position, door clearance, and finished tile height. A standard 1200 by 900 millimetre tray may fit the drawing, yet still cause trouble if the waste clashes with a joist or the bathroom door swings over the tiled area. I have seen installers cut first and measure later. That mistake often creates several hours of repair work.
Older timber floors need special attention because movement can transfer into tiled surfaces and sealed joints. I walk across the room, listen for squeaks, and check for soft spots around the previous shower or bath. If the floor drops by even a few millimetres near one wall, I deal with that before setting the tray. Small errors travel.
A customer last winter had already bought a large tray for a narrow upstairs bathroom. The dimensions appeared correct, but the planned glass screen would have left less than 500 millimetres for entry. I adjusted the tray position and moved the waste slightly, which gave us a more comfortable opening without changing the main layout. That small revision made the shower much easier to use.
Choosing the Tray Around the Actual Installation
I choose the tray size after confirming where the waste can run and how the surrounding boards will meet it. For a recent conversion, I used a Drybase shower tray because the low profile suited the existing floor build-up and the planned tiled finish. The tray also gave me a clear base for forming the shower area without building the falls by hand. I still checked every dimension before cutting the surrounding boards.
A manufactured fall can remove much of the guesswork, but it does not correct a twisted or unsupported subfloor. I dry-fit the tray and place a long level across several directions rather than checking only one edge. A 2 millimetre gap under one corner may appear minor, yet it can become a flexing point after the tile and glass are installed. That detail matters.
I also think about tile size before fixing anything permanently. Very large tiles may be awkward around a central or offset drain because the tray has falls running from several directions. Smaller formats usually follow those changes more naturally, although the exact choice depends on the tray shape and tile thickness. I often lay a few loose tiles over the tray to see where cuts will land.
Subfloor Preparation Decides How Solid the Shower Feels
On timber floors, I want the tray supported across its full underside rather than resting on a few proud screws or uneven board edges. I check joist spacing, reinforce weak areas, and replace any damaged sections before continuing. In many houses I work on, the joists sit around 400 millimetres apart, but old alterations can create irregular gaps. I never assume the structure is uniform.
A bathroom I repaired last spring had an 18 millimetre plywood floor that looked sound from above. Once I lifted the old covering, I found that a previous leak had weakened a narrow strip beside the waste pipe. The shower had felt slightly springy for months, even though no cracked tiles were visible. Replacing that section gave the new tray a firm and predictable base.
I cut the waste opening with enough room for the fitting and connection, but I avoid removing more structure than necessary. Access from below can make the job easier, especially if the trap needs checking after the tray is positioned. Where access is limited, I assemble and test the waste before final fixing. I pour several litres of water through it and inspect every connection.
Waterproofing Must Continue Beyond the Tray
I treat the shower tray, backer boards, corners, pipe openings, and doorway as one connected waterproof area. A good tray cannot protect a wall joint that has been left open behind the tile. I use the sealing products intended for the board system and follow the required overlap at tapes and membranes. Mixing unrelated materials can create weak bonds.
Internal corners receive extra care because slight building movement often appears there first. I press the sealing tape into the corner without stretching it and remove trapped air before the compound sets. Around pipe penetrations, I use properly fitted collars rather than relying on a thick ring of silicone. Silicone has a useful role, but it should not carry the whole waterproofing job.
Drying time also affects the result. If a coating needs 24 hours before tiling, I give it that time rather than judging it by surface appearance. Some products feel dry on top while remaining soft underneath, especially in cool rooms with little airflow. Rushing this stage can pull the waterproof layer away while adhesive is being spread.
Tiling the Falls Without Creating Drainage Problems
I begin the tile layout at the drain and work outward, because the drain cuts are the most visible and least forgiving. A narrow strip beside the waste can look untidy and may be difficult to bond properly. I aim for balanced cuts while keeping grout lines aligned with the wider bathroom where possible. Sometimes the best tray layout is slightly different from the main floor pattern.
Adhesive coverage matters more on a shower tray than in many dry areas. I spread the adhesive evenly, keep the notches consistent, and lift occasional tiles to check the contact underneath. Hollow areas can allow movement and may hold water if a grout joint later fails. I do not rely on spot bonding.
The fall must remain clear after the tiles are installed. Thick adhesive under one tile can create a small ridge that leaves water sitting near the drain or wall. I use a straightedge across adjoining tiles and check the surface from several angles. A joint width of 2 or 3 millimetres gives enough room for neat alignment without hiding poor cuts.
Finishing Details Protect the Work Over Time
Once the tiles are secure, I grout the field joints and leave movement joints for a flexible sealant. I clean the edges before applying silicone because dust and grout residue weaken adhesion. A smooth bead should bridge the joint without being spread into a thin film across the tile face. I usually mask both sides when the tile has a textured surface.
The screen or enclosure should be fixed without damaging the waterproofed tray area. I plan the fixing points during the board stage, adding solid support where hinges or channels will sit. Drilling through the horizontal tray surface is something I avoid. Wall fixings are easier to seal and inspect.
I test the finished shower before handing it over. Water should move toward the drain without collecting in corners, and the waste should cope with the shower’s normal flow for at least 10 minutes. I also inspect the room below if access is available. A careful test is far easier than returning after the ceiling has developed a stain.
A Drybase shower tray works best as part of a planned floor and wall system rather than as an isolated product dropped into an empty space. I get the most reliable results by measuring the room twice, supporting the tray fully, and carrying the waterproofing beyond its edges. Those steps are not dramatic, but they decide whether the shower still feels solid years later. Good preparation stays hidden, which is exactly where it belongs.