Here's how to make your new shower stall leakproof
Ignorance may be bliss, but a water-saturated shower stall can leave you all
wet. If moisture penetrates the grout below the stall's tiles, you'll
eventually
see mildew in the shower or, worse still, water damage on the ceiling below
it.
Building a leak-proof shower can be challenging. Thorough preparation and
the right materials will help ensure success
The two hardest parts of a traditional installation of a new shower
stall are properly sloping the mortar bed to the drain and preventing
moisture
from getting behind the tiles and saturating the mortar. A new,
all-in-one-box kit from Schlüter Systems comes with everything that someone
building a
new shower needs to overcome these traditional difficulties.
The key components are a pre-sloped, two-piece high-density extruded
polystyrene tray that replaces the mortar bed, and an 8-mil polyethylene
waterproofing
membrane (called "Kerdi") that's used to encase the entire stall. The kit
includes 108 sq. ft. of membrane in a 39 1/2"-wide roll and smaller
four-inch-wide
strips to overlap all seams. The tray comes as a 4' x 4' square or a 32" x
60" rectangle for converting a bathtub to an oversized shower.
already had a two-by-four curb built in, but for new construction the
kit also includes a 4' length of polystyrene curb.
Another unique aspect of the kit is the drain itself, which has a
square surface. Unlike a standard circular drain surface, you don't need to
cut the
edges of the tiles where they butt up against it.
Everything is bonded in place with a fine layer of thinset concrete.
Installing the tray and waterproofing should take a competent DIYer less
than
a day, with a second day needed for the tile installation.
The kit is available as a special-order item at Home Depot and through
select tile retailers for about $500. Individual components are also sold
separately.
1. The kit includes a template for cutting the subfloor to size. Use the
template and a jigsaw to cut the drain hole in the floor. Ideally, the drain
should
be centred in the shower stall
2. The kit's polystyrene base pan can be cut to size with a utility knife or
saw. Remove the excess polystyrene evenly from all four sides to maintain
the
pan's even slope to the drain
3. Use a steel trowel to begin laying down an even layer of thinset mortar
on the subfloor. Cover the floor completely, as the thinset acts as the glue
that will hold everything in place
4. Lay the tray in place and step gently on it to press it into the thinset.
After drain installation, lay down a piece of plywood on top to protect the
base while you work on the walls
5. Apply a layer of thinset to the drain area, then dab the drainpipe with
ABS cement and set your drain into place. Trowel and sponge off any excess
mortar
from the drain area
6. As with the tray, thinset is used as an adhesive for the Kerdi
waterproofing membrane. Trowel a thin stripe of mortar around the base of
the shower where
the walls meet the floor
7. Lay the four-inch-wide strip of the waterproofing membrane into the
thinset all around the base of the pan and overlap it at the seams by two
inches.
Smooth membrane with a scraper
8. With the walls covered in thinset, start pressing sheets of the
waterproofing in place. Overlap each piece and use a scraper to smooth out
any air pockets
trapped underneath
9. With the entire shower stall-including the base pan-now covered in an
overlapped layer of the waterproofing membrane, you should be ready to begin
tiling
the shower stall walls
10. We used an irregularly shaped flat stone for this project, but the
application technique is the same for all shapes of tile. Use a notched
trowel to
spread the tile adhesive on the wall surface, then begin applying the tiles
11. Dampen the joints between the tiles before applying the grout. Next,
fill the joints using a rubber-faced float held at a 45° angle, being sure
to push
the grout as deeply as possible into the joints, filling them completely
12. Wipe the tiles with a sponge to remove extra grout and smooth out the
lines. After about 30 minutes, use the sponge to clean the tile surface
before
the grout hardens. Wait 24 hours, and the shower will be ready to use
