Below is a guide to installing single sized tiles only - if you are installing a pattern
, due to the sizes of the tiles used in these patterns, regulated grout lines cannot be guaranteed and therefore the laying by eye rather than using spacers is recommended.
Unpacking & Mixing Slate Tiles
Follow the steps below & you will achieve a better looking floor for your efforts.
Upon delivery of your new slate tiles, I recommend that all tiles are taken out of there packaging/boxes and stacked vertically against a wall.
If you have chosen tiles that are heavy in variation then I suggest that they are sorted in to there appropriate colour/mix variation, you may end up with 5 or 6 different piles but this is good, it is better to sort the colours now for your Slate Flooring Installation rather than to just lay them without sorting & have a floor that has not been blended very well, this can be very disappointing to see after completion & to be honest it doesn't take very long to do.
Once you are ready to begin your Slate Flooring Installation, I suggest that you lay your tiles according to the selections you have & blend the tiles well, try to mix the tiles in evenly as you go, making sure that when you come to the last few tiles in each stack, you have an equal number left according to how many was in each stack to begin with.
I suggest that you do a dry run to familiarize yourself with the overall colour variation & to get a feel for the thickness & spacing of each tile, time spent here will save you from rushing when you start to apply your tiles with the adhesive, any mistakes can easily be rectified at this stage, as once adhesive is mixed you will only have so long to use it.
A Tip For You
Another way of making your Slate Flooring Installation easier would be to grade your tiles by thickness, this can easily be done by the eye & I would suggest that once this is done that you start to lay your tiles with the thickest first, this will create a much flatter floor with no raised edges from tile to tile on completion of you slate flooring installation.
Do not worry about dust or dirt on the surface of your slate tiles as you are laying them, this can be removed/cleaned after installation on to your adhesive.
Removing Old Flooring
You may have to begin by removing any old floor tiles to reveal the substrate beneath it, this would be the perfect situation for most floors prior to your slate flooring installation. If you have to remove an old floor prior to your slate tile installation then you must ensure that the underlayment is solid, not crumbling or deteriorating in any way, if the subfloor looks in a bad way then I suggest you seek the advice of a professional builder before laying a single tile.
Once your old floor has been removed, check that the floor's surface is level, dry & free of grease, oils & dirt.Tile To Existing Flooring
If however you decide to lay on top of an existing tiled floor then you will have to make sure that it is solid, clean & that a bonding agent is applied prior to fixing, it is also advised to use a flexible adhesive & grout to account for any future movement which may occur. You may also have to resize any existing doors to account for the additional raise in the height of the floor.
When installing on to a new concrete base you must allow 1 week drying time for every 1 inch of concrete. Most new concrete bases are to rough to allow for thin set beds of adhesive, most new build floors are finished to a smooth finish so thin setting will not be a problem.
Sand & Cement Screed
A fresh screed can shrink during drying which can create cracks, this can cause tiles to split if the screed has not been given enough drying time prior to slate flooring installation. Screeds can be applied unbonded to a concrete subfloor & it is advisable to lay a polythene damp proof membrane under a standard 50mm screed which in turn will require 1 week for every 25mm of screed depth.
Use an Acrylic Bonding & Priming Agent for maximum adhesion to your subfloor whether it is an old or new concrete screed.
When tiling on top of existing timber floors, i.e. Tongue & Groove boards, it is best practice to use 15mm WBP (water boil proof) Marine Plywood screwed down at 200 – 300mm intervals, a more solid method would be to cross lay 9mm WBP Marine Plywood on a horizontal direction screwed down at every 300mm intervals & then overlay a second layer of 9mm WBP Marine Plywood on a vertical direction screwed down again at 300mm intervals, this method is recommended for floors that tend to have more flex within the overall floor. It is also advisable to leave a small gap between each sheet used to allow for expansion & also to leave a small gap around the perimeter.
For areas that are prone to damp & moisture such as bathrooms & shower areas (especially shower wall enclosures), it is advised to use a tile backer board such as “No More Ply”, this is dimensionally stable & water resistant & will not shrink or crack.
You must use a Flexible Adhesive & Grout when laying on to a wooden surface.
Most old floors will have small bumps & dips, this can be overcome by applying more adhesive to the back of the tile at the time of you slate flooring installation, for more extreme & very uneven floors you should use a self leveling compound, this will bring these areas when installing slate, back up to a workable level & stop tiles from sagging or dipping. This can occur if to much adhesive is applied to the back of the tile when trying to bring it up to the correct level.