Grouting and sealing unglazed tiles

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Aug 5, 2008, 7:08:18 AM8/5/08
My partner and I chose some unglazed porcelain mosaic tiles for the
small cloakroom that we are currently refurbishing. Work has now
reached the tiling stage, starting with a small splash back to the
corner wash basin. There is also a small window sill and the whole of
the floor to be tiled with the same mosaic tiles.

This seemed a good time to ask advice about how, when and with what to
seal the tiles, and which grout to use. There is much advice on
grouting in the archives, however I could not find anything that
referred specifically to unglazed porcelain.

I have a bottle of Plasplugs Tile Sealant which seemed suited, but the
blurb on the container suggests that this is more of a pre-treatment
before waxing. There is no suggestion of what wax product should be
used ...

Sealing the tiles before fixing them to the wall would seem sensible
in order to prevent any adhesive and grout marking the unglazed
surface of the tiles. Can anyone suggest how best to approach this,
what products would be most suitable and in which order they should be
applied relative to tiling and grouting?

Dave Plowman (News)

Aug 5, 2008, 8:48:00 AM8/5/08
In article <>,

Bruce <> wrote:
> My partner and I chose some unglazed porcelain mosaic tiles for the
> small cloakroom that we are currently refurbishing.

Interesting - what colour are they?

*Why do overlook and oversee mean opposite things?

Dave Plowman London SW
To e-mail, change noise into sound.


Aug 5, 2008, 9:18:45 AM8/5/08
"Dave Plowman (News)" <> wrote:
>In article <>,
> Bruce <> wrote:
>> My partner and I chose some unglazed porcelain mosaic tiles for the
>> small cloakroom that we are currently refurbishing.
>Interesting - what colour are they?

The individual rectangular tiles are varied colours, from dark blue to
blue-grey to grey to off-white. They are called Hoxton black and
white mosaic, although there are no black tiles and the white is very

We got them at Homebase. There is a similar mosaic of brown/cream
tiles that are equally attractive.

They are normally quite expensive at £15 per 0.36m2 box containing
four 30x30cm mosaics, which is over £40 per m2. But we got them in
the sale a few months ago for £2.50 a box.

They are still in stock but the price has risen back to £15. They
don't appear on the Homebase web site, otherwise I would provide a

stuart noble

Aug 5, 2008, 10:12:40 AM8/5/08

Will you glue the towel rail, or do you have a couple of hours spare to
drill holes?

The Natural Philosopher

Aug 5, 2008, 7:34:53 PM8/5/08
No idea if this is kosher,but I always stick things like that up bare,
clean any tile cement off with brick acid or de-scaler, wash them down,
seal, then grout.

Lithofin sealer usually.

Andy Hall

Aug 5, 2008, 8:40:34 PM8/5/08

What effect do you want at the end? Do you want them to come up to a
glossy type of finish with a wax?

I've done and/or specified quite a bit of tiling with various types of
stone and with unglazed ceramics. Basically, I hate highly polished
tiled surfaces and especially screen printed ones - they remind me of a
printed photo in a newspaper.

Anyway, that aside, I've always used Lithofin products. They have a
very comprehensive range of treatments and cleaners for all types of
stone and ceramic.

For stones such as slates, I tend to like to have a rich colour but
without raising the sheen too much above matt - certainly not glossy
stuff. To achieve that, Colour Enhancer and MN Stainstop can be
used. The latter is an impregnator.

For limestone and similar, I have tended to use MN Stainstop only.

The procedure with stone is either to do a first seal before fitting
(tedious) or to do that after fitting but before grouting. The
latter assumes that you can work carefully with the adhesives and means
using the right notched trowels etc. To that end, it really is worth
investing in decent adhesives such as Ardex or BAL in powder form - not
readymix. Go for the longer setting time version.

Either way, after fitting the tiles, waiting and grouting and cleaning,
a final coat of impregnator should be applied, possibly two. This
will leave a matt and natural looking surface for unglazed tiles
provided that you follow the instructions, using it sparingly and not
allowing it to puddle on the surface.

There is a similar set of products for unglazed ceramic and porcelain
and yet another for glazed. If you look on you will
find materials lists and method statements for each product set and
material. It appears that Lithofin FZ will be what you want.

One thing that is important for the sealers in a confined space is to
make sure that you use a proper solvent filtering face mask. These
have filter cartridges that can be replaced or there are
semi-disposable types. You definitely don't want to breathe the

You will find Lithofin stuff in good tile shops. What is important is
to try out the sealer on a small area of tile. Sometimes a tile shop
will have an open can of the sealer you want to buy and will wipe it
over a tile for you. Otherwise, buy a very small can. It is qute
expensive but goes a very long way. 500ml will probably do you for a


Aug 6, 2008, 5:17:30 AM8/6/08
Bruce <> wrote:

I would be grateful for any advice. Please?

I know unglazed tiles aren't as sexy as Macintosh computers, but at
least they are on-topic! ;-)

Andy Hall

Aug 6, 2008, 6:37:29 AM8/6/08

I wrote an article on this yesterday giving you detail on how to use
Lithofin products to achieve this.

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