How to Install a Wet Room Shower Tray
This installation guide shows how to install wet room kit shower tray Showerlay Wiper on a wooden floor and how to tile it over.
After placing an order for one of shower trays for wet room in our offer you will receive foam based XPS with 2% fall prepared during manufacturing process from every corner of the tray to every corner of the drain, with integrated waterproof stainless steel channel. Shower tray is reinforced with fibre glass mesh and cemental glue layer. Drain is built in during production process, wateproofed, suitable grate and McAlpine siphon trap included.
Showerlay former board can be 20, 28 or 35 mm thick. Drain goes 15 mm above the shower tray and approximately 50 mm below the bottom surface. Upper surface is slope while bottom is even. The thicker shower tray, the more noticeable fall is. Depending on your existing floor board thickness (usually 20 mm) and future wet room layout you need to decide which thickness is right for you. It requires underboarding with at least 20 mm thick marine ply, which can sit between the joists, so if your floor board is 20 mm thick, shower tray of that thickness will mean that there's no floor height increase.
Tanking kit can be included to your wet room kit to receive additional package with insulation materials. Each tanking kit covers 3.2 square metres and contains useful materials to make your shower and splash area wateproof, which is highly recommended. Additional sealing materials can be bought from our Construction chemicals category. In depth guide is available on DIY insulation guide page.
Showerlay drain itself is waterproof but the joists, connections between floor board and shower tray and rest of the room require tanking. Wateproofing entire shower room is optional, however tanking shower area and splash area is mandatory and should be always undertaken prior to installation.
1. Prepare floor and walls and clean them from dust, debris. Remove garbage and make sure you have sufficient space for comfortable work. Prepare materials and tools necessary to complete the installation, you will probably need a level, jig saw, drill driver, utility knife, screwdriver, pencil, hammer, brush, notched trowel, tile adhesive. Handsaw can be used to trim the shower tray to trim to size, but equal distances from both sides should be cut to preserve proper fall towards the drain. 
2. Establish future shower area by placing the shower tray on top of existing floor boards. Make sure shower tray is sits tightly in the corner. Use pencil to draw perimeter around board and inside to drain outlet to mark the position of the tray and waste. 
3. Use jig saw to cut across the previously marked shower tray shape. Remove existing floor board to exspose the joists. Please notice that the standard thickness of floor board is 20 mm, however if it's thicker than thicker shower tray will be more suitable. Make sure you remove the floor board back to the centre line of the closest joist to ensure maximum support. There might be a necessity to move floor boards around the tray to ensure tight fit. 
4. Find the best possible drain position and angle to connect it to your pipe work. Siphon trap can be rotated in 360° and waste pipe's height can be adjusted, giving much flexibility for proper positioning. Create a plywood support below the future siphon trap position, approximately 65 mm below the top of the joists. Make sure it sits in correct place which allows it be connected to your waste system, test connection between the siphon trap and pipe. 
5. Connect a standard 50 mm compression pipe into the end of the siphon trap. Ensure you will be able to assemble the siphon trap with upper fixing part from above of the steel drain channel. If you are sure that the siphon trap is well supported in correct place use silicone sealing adhesive to fix the siphon trap's pipe to your waste system. Now perform a simple test if water flows correctly by pouring water into the siphon. 
6. Prepare timber support battons and plyboards for shower tray underboarding. Showerlay requires at least 20 mm thick marine plywood support. Cut 30 x 50 mm battons and fix them to the sides of joists approximately 20 mm below their upper level, ensure that ply will sit flushed with rest of the floor. Fix prepared runners to joists and then ply to them using nails or screws. Make sure solid, even support is created over entire shower area. Cut a hole matching the linear drain shape, as it goes below the bottom shower tray surface for approximately 5 mm. Channel doesn't require underboarding, while siphon trap and bottom Showerlay surface does. 
7. Put the Showerlay down to check if it sits in correct position and if it's flushed with rest of the floor. Check if you are able to connect the siphon upper part with waste trap underneath the shower tray and if it sits on previously prepared support. Use the level to check if the tray is even and if the drain channel is the lowest place in the shower area. Test if the linear drain channel matches the hole in ply support. 
8. Apply 0.5 - 1 mm standard tile fixing adhesive over the created support using nothed trowel. Ensure the adhesive layer is even over the entire area. Stick the wet room kit to the plyboard and assemble the channel drain with the siphon trap below. Use silicone to seal the white part of siphon which is used to be screwed down the trap from above and fix to the channel. Make sure everything is well supported and sits in correct position. Wet room should now be flushed with remaining area of the room. 
9. Distance from the shower tray surface to the top edge of vertical drain frame is 15 mm, so if you need to build up that space, use tile backer boards. They are perfect material to tile over and should be used as well over the rest of the floor. Wateproof the connections between boards and also floor/wall connections using tanking liquid and waterproof tape contained in waterproofing kit. Apply sealing corners and pipe collars where necessary. Liquid foil can be used as adhesive to stick these. 
How to Install a Wet Room Shower Tray
Source: https://wetroomsdesign.co.uk/wet-room-kit-shower-tray-installation-instructions-timber-floor