Laying guides
These guidelines are intended as preliminary reading only.
Island Stone manufacturers recommend selecting membranes, adhesives, grouts from the same manufacturer many whom produce very detailed advice on surface preparation, tile laying and product specification. We emphasise the importance of using products with good technical back-up. Employing the good trade practice of testing areas first.
V-Tile Installation Guide (227 KB)
V-Tile Laying Patterns (227 KB)
Geotile Laying Guide (1815 KB)
topics in this section:
All substrates
should be firmly fixed, flat, clean, dry and free of contaminants.
Deflection should be a maximum of 1/360th of the span for walls
or floors. Concrete substrates and the mortar in bricks or blocks
must be allowed to cure for 28 days minimum, cement render for
7 days minimum.
Painted surfaces must be sound after roughening with sand paper
or wire brush. water based paints are not suitable substrates
for tiling. Previously tiled surfaces should be firmly adhered,
acid etched and roughened before over-tiling.
Wet areas
require special attention involving appropriate substrates (e.g.
concrete, compressed sheet, water resistant plasterboard, treated
plywood) the use of reinforced waterproof membranes and in the
case of floors a fall to the drainage point of not less
than 1:60.
The stone tiles have the infinitely varied characteristics of nature. It is recommended tiles are laid dry and arranged if necessary to avoid abrupt colour or size variations. Crystal marble may be especially sensitive in this regard.
The manufacturer's
literature will explain if a product is suitable for interiors
and / or exteriors as well as walls and / or floors. A recognised
adhesive manufacturer will have a range of products each appropriate
to different substrates / potential substrate movement.
Cement based water mix adhesive is generally suitable on masonry
substrates where no movement is anticipated. Where slight movement
could occur through thermal or pedestrian loads a modified cement
adhesive (probably two part) should be used as a minimum.
It is important that each pebble is embedded in the adhesive.
Select a product suitable for application with a 10mm notched
trowel, and apply no more than about 1m2 of adhesive
at a time.
Easier results are achieved with the lighter grade tiles 8mm,
11mm, 14mm thickness. The heavier grades 17mm & 20mm may have
to be laid individually.
These prevent
the leakage of water through to sub floor or wall framing and
/ or habitable spaces below. Particular attention must be paid
to carrying the membrane up the wall, outside shower boxes, installation
of bond breakers and sealing around penetrations.
It is strongly recommended that membrane systems are used in all
wet areas, including exterior suspended decking. Some systems
involve the use of a primer.
This procedure
can make the eventual removal of grout easier and may be carried
out before the tiles are laid or just before grouting.
After ensuring the sealer is appropriate apply in accordance with
instructions, remove any excess and leave to dry for at least
an hour before proceeding to
lay or grout.
Ensure the sealer used is the same as or compatible with your
final sealer. IMPORTANT! Test the sealers on an area first to
ensure it is giving you the result you want and is compatible
with the stone tiles.
The grout
should be suitable for joints up to 15mm in width and designed
for external or internal conditions as your case may be. Generally
grouts are water mix but where some flexibility may be needed
then a latex additive or similar should be used in place of the
water.
Experience indicates coarser grout works well in relatively large
joints and is easier to use. In wet areas, however, finer, less
porous grout should be used.
It is important to wait only the interval recommended by the adhesive
and grout manufacturer before grouting to minimise dirt ingress
between the pebbles and avoid the opportunity for other trades
to dislodge pebbles.
There are
numerous reasons for building movement and control joints divide
a larger tiled area into a series of
smaller ones.
Joints can be easily formed with two angles; sealant and bond
breaker between them.
Designers may show points at which joints are needed but certainly
where tiles adjoin walls or some other building material and where
there is a control joint in the substrate among other circumstances.
The pebble sheets can be easily fitted around a gently curved surface - a column for example. If the sheet is turned around a right angle some stones will need to be plucked off the mat where they are distorted at the corner point and replaced with smaller pebbles to maintain uniformity at this point.