[Music] Hello and welcome back to Prep Set Go. Thanks once
again for joining us it's great to have you here. In this video we'll be looking at tiling over
existing tiles and covering the preparation and general considerations that go with it - so let's
get started. Tiling over existing tiles is very common practice, particularly in the renovation
space. It's a practical solution when you want to maintain the function of a space while giving the
area an update or a refresh. The practice can save both time and money, eliminating the need to rip
up the old tiles which can be both labour and time intensive. It's far less invasive and noisy and
doesn't create dust and the added inconvenience of extra waste that needs to be disposed. Now,
although this is far more convenient than the alternative, there's still a number of things to
consider when determining if it's even feasible. So let's explore some of these. What would the
impact be on floor heights? An obvious impact of tiling directly over existing tiles is the raising
of floor heights on horizontal surfaces. Will this become a trip hazard - particularly at doorways.
Will transition strips be needed or even practical to bridge and ramp the transition. Do doors
and architraves need to be shaved down? Does skirting need to be raised and retrofitted?
Is there sufficient set down in wet areas and showers to accommodate the elevated finish? Will
the substrate be capable of accepting the weight of a whole new tile layer? This is particularly
important for vertical applications on lightweight wall sheeting, and timber floors where the added
weight will increase stresses on the structure that may lead to increased flexing, deflection,
and movement. So after these initial conditions, you've determined that it is feasible. Let's
move on to the practical steps of preparing the existing tiles. First off, tiles need
to be sound, stable, and well bonded, as we've spoken about in previous videos on surface
preparation - finishes are only as good as the surface they're bonded to. The existing tiled
surface must be well bonded to the substrate, and not loose or drummy - and drummyness is that
hollow sound when you tap a surface, indicating that there's separation of the tile or adhesive
from the substrate. So a thorough inspection of the entire surface should be conducted and any
loose, cracked or drummy tiles should be removed and patched with a suitable repair or levelling
compound, and you can refer to the extensive range of RLA surface preparation products for
details. Extensive cracking and delamination of tiles could indicate a defect in the substrate,
or an underlying issue and may require complete removal of the tiles and inspection and repairs
of the underlying substrate. So we've done our inspection and made some repairs, now we
need to ensure the surface is thoroughly clean to enable a good bond to the surface -
and again please refer to previous episodes on the importance of good surface preparation.
Tiled surfaces should be free of all dirt, dust, grease, soap, detergent, chemical residues,
and any other surface contaminants that could affect the adhesion of our new tile layer. The
type of cleaning will be based on the process we'll be using to bond the new tiles, so this can
either be directly with suitable tile adhesives, or through the use of special primers such as the
RLA Universal Primer which is designed to allow finishes to bond to smooth or non-porous surfaces
like ceramics, metals, and plastics. Tiling directly to the existing tiles will often require
the removal of the tile glaze, and roughening of the surface to promote good adhesion - and please
remember when roughening the tiles don't forget to use appropriate protective gear. Including
mask, safety glasses, and hearing protection. Mechanical grinding and washing down or vacuuming
of the surface will remove the bulk of surface contaminants, when using special primers
where removing the glaze is not as critical, cleaning solutions, detergents, or degreases,
can be considered - paying particular attention to grout lines where contaminants can accumulate.
And now for adhering the tiles. First and foremost always use a high quality tile adhesive.
You've done the hard work in the preparation, so you'll want to ensure a decent adhesive
is used to ensure a quality job. We recommend using a C2 class adhesive which is classified as
having improved adhesion and RLA have a number of suitable adhesives in their range to consider.
And remember to always refer to the product data sheet for suitability for use over these
surfaces, or if unsure call us directly where one of our friendly staff will be more than happy
to help. Thanks for joining us in today's episode, if you have any questions or comments please
feel free to leave them down below, or send us a message via our social media channels. We
look forward to seeing you next time. [Music]
