# Tiling onto MDF



## Anonymous (21 Dec 2005)

Off the woodwork topic I know.... 

Just built a vanity unit for the new cloakroom (why did I start this so close to Xmas!!!??) I am planning to clad the vanity frame in MDF and then tile it with ceramic tiles.

I have been searching t'internet all evening, and havent found an answer, does anyone know if I can tile (vertically) onto MDF? Or do I need some sort of mesh or sealer?

Will be asking the guys at Tile Magic tomorrow, obviously, its always good to get a realistic opinion from you guys as well!

Any help much appreciated.

BL


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## superunknown (21 Dec 2005)

Yep you will need to seal it. Thinned down PVA does the trick.

Have fun!


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## JFC (21 Dec 2005)

If you tile directly on to normal mdf ( not exterior mdf ) i think it will blow and therefore your tile adhesive wont stick so the tiles will fall off over time . There is a product that is used in wet rooms but i cant think of the name  Its a waterproof webbing that is fixed to the surface of the wood but has good suction for tiles .


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## Jake (21 Dec 2005)

Better to use WBP ply and a timber approved flexi-adhesive, or wediboard/luxboard/aquapanel.


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## engineer one (22 Dec 2005)

thinned down pva is the way to go, and should dry within about 4 hours.
do the normal thing of putting a batten at the lower edge to keep the things straight.

there are some higher strength tile adhesives that my local pro's use.

paul :wink:


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## PowerTool (22 Dec 2005)

Thinned down PVA is NOT the way to go - a topic of much debate over at Screwfix forums.
If you go there,search for posts by "Mudster" which will explain why.(Briefly,tile adhesives crystallise rather than dry,PVA forms a semi-permeable barrier which is partly re-activated by the moisture in the tile adhesive,and your tiles fall off  )

Aquapanel or Wedi-board are designed for tiling onto,MDF and PVA isn't.

Andrew


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## jasonB (22 Dec 2005)

First I would like to know what type of MDF you have used, at the minimum it should be Moisture resistant, better still Exterior. The reverse side and all edges should be sealed with varnish or painted.

As it is only the sides of a vanity it will not be subject to very wet conditions so there will be no need to apply a tanking system. You will need an adhesive that is suitable for MDF, of the large BAL range only White Star and Mosaic Fix are suitable (excluding tile&grout) of the two I would go with Whitestar as it is premixed and allows for a small amount of movement.

PVA *SHOULD NOT* be used as a tile primer in 99% of cases and its use will invalidate ant gaurantee by the adhesive makers of their product working. You could apply BAL ADP which would help stop the water in the adhesive being sucked in too quickly and affecting the drying of the adhesive.

Use a grout that also allows for movement such as BAL Superflex.

Jason


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## Scrit (22 Dec 2005)

PowerTool":3clxonhi said:


> PVA forms a semi-permeable barrier which is partly re-activated by the moisture in the tile adhesive,and your tiles fall off  )


If you ensure that your PVA is a D3 specification (this is an EU standard for exterior grade PVA) that won't be the case. D3 PVAs are cross linked so they cannot be reactivated by contact with water. Couldn't say if D3 is suitable for this but I'd second the comments about using MR-MDF

Scrit


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## engineer one (22 Dec 2005)

sorry, if i misled anyone, but that was what the guys who were paid to do the job here did.

obviously the green mdf is a better item to use for this project.

but the other way is surely watered down emulsion and then the tile adhesive. frankly like most people it did not occur to me that 
there was any worthwhile warranty from the adhesive guys to 
disable.

anyway good luck for the season
paul :wink: :ho2


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## WoodPecker (22 Dec 2005)

You could tack on some plaster board and tile on to this as normal.
Or if you have to tile on to mdf or ply I'd use flexable adhesive, same type used for tiling onto wooden floors, there's a 2 part one where you mix a powder with a liquid which is very good.

*Edit: Think the adhesive is made by BAL*


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## andrewm (22 Dec 2005)

Is it really going to matter for a vanity unit? Before I knew any better I used MDF for the side of my airing cupboard onto which is mounted a power shower. This was sealed with PVA and then tiled on top with a waterproof adhesive and waterproof grout. The shower has been in daily use for the past six years with no problems. 

Andrew


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## Jake (22 Dec 2005)

Against that, why use an inappropriate material that may increase the risk of failure when there are more appropriate materials that are just as easily available at a similar or negligible extra cost?


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## RogerS (22 Dec 2005)

Remember this thread ?

https://www.ukworkshop.co.uk/forums/viewtopic.php?t=3977&highlight=shower 

I wonder how he's doing?


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