t is important to ensure that surfaces and plywood flooring underlayment are totally waterproof, while providing proper water drainage. This is crucial to project success and structure durability.

There are several methods available for proper drainage and waterproofing:

• A gradient floor system with slopes and channels to drain water toward the drain. This must be fabricated into the floor system using water resistant or water proof plywood. Exterior grade construction plywood and treated plywood are manufactured using waterproof glue in the lamination process. Both types of plywood are water resistant to a degree, but require sealant to keep the laminated layers of wood from absorbing moisture.

Plastic marine plywood engineered from plastic polymer, on the other hand, is totally waterproof and not affected by moisture in any way. However, avoid types which are made by laminating small bits of plastic into sheet goods. They contain different types of plastic that expand and contract at differing rates - detracting from the tensile strength of the sheet.

• The gel membrane system also known as “tanking,” is a fiberglass sealing kit that can be applied to the plywood sub-floor and walls. This should be allowed to cure before installing bathroom tile.

The Design Quality Indicator (DQI) is a pioneering process for evaluating design quality of buildings, it can be used by everyone involved the development process to contribute to improving the quality of our built environment.

• Pre-molded tray kits have the sloping gradient and drain already built in. The tray is set into the room; plumbing connections are made, and then tile is installed on the tray and wall surfaces.

• Another method is using plywood of choice for the subfloor with no gradient, with a drain installed and surfaces tanked. Waterproof leveling compound is troweled on or “screeded” to provide a sloping gradient toward the drain. Tile is then installed over cured leveling compound and on wall surfaces.

• Certain types of rubber roofing material can be also be used to waterproof floor and wall plywood. When seeking the services of a waterproofing contractor, consider a flat roofing contractor. A flat roofing contractor can install an EPDM rubber membrane or modified rubber; applied in sheets and heated to weld seams. Tile can then be installed to the membrane using a special adhesive.

Additional Tips

When installing tile in wet rooms, it is best to use non-porous tile, such as ceramic. Slate, granite, marble and limestone tile is porous and requires re-sealing every 2 to 3 months to keep moisture from penetrating, and causing damage to the subfloor.

Instead of tile, sheet goods such as vinyl can also be used; seams should be properly welded to form a waterproof barrier. Regardless of the type of material used, be sure that all Canadian building code requirements are met by contractors hired for the job.

While most local building code requirements are based on International Building Code or National Canadian Building Code guidelines, code specifics can vary from one community to another. Homeowners and contractors should work closely with the local building authority, to ensure code compliance.

Find Reliable Local Contractors

At HandyCanadian.com homeowners throughout Canada who want to convert a small bathroom into a tile wet room can locate reliable professionals easily, quickly, and without cost or obligation.

Homeowners simply sign up for free and post their small bathroom remodel project online, where it is immediately visible to local professionals 24/7. Contractor members also receive immediate e-mail notification of new project listings in their area, and provide competitive bids in days – even hours from project posting.

View contractor company profile pages online at HandyCanadian.com; including references, customer feedback, licensing and insurance credentials. As well as a photo gallery of company staff and recently completed projects. And then make an informed hiring decision, or hire no one at all. Remember, there is no obligation whatsoever, and services are free!