Tiling a window reveal

[Dougalogic]

Hi folks,
I'm on to the last wall of my bathroom and have decided to tile the window cill and reveal. Before I do can someone tell me is it ok to tile onto the wood i.e. the cill and reveal, or should I take it all out first? Also, what is the best finish for the exterior corners? I thought a trim but a plumber told me a bead of Silicon would be best
Cheers in advance
Dougal

 

[Muse2k8]

You need to check how level the cill is first then cut the tiles up to it to be all level first. That way when you add trim (if not stone) you get a level surface. Then if need be pack out the tiles behind it.

Dont know if this makes sense... It's late...

 

[Muse2k8]

Oh and what wood is the cill made from?

 

[doug boardley]

if you have enough depth between your cill and the glass in the windows why not screw some plasterboard onto the cill?, If you're using ceramic or porcelain tiles use trim for the external corners.

 

[DHTiling]

I would remove. Thermal Expansion from sunlight or room temp will cause the timber to expand and in turn crack around the joint.

Remove and dry line out.

 

[jay]

Do not listen to the plumber

 

[AliGage]

I would remove. Thermal Expansion from sunlight or room temp will cause the timber to expand and in turn crack around the joint.

Remove and dry line out.

What Dave said. Ideally you want it out.

I've also neither heard or seen someone use Silicon for an external joint. Use trim, it's a neater finish, certainly if this is your first effort at tiling.

 

[Polishtradesman]

I recommend to remove all wood pices and fix plaster or cement board instead of it. Best finish is cutting tile edges 45 digree like i done on this job Picture 7 of 16 from Woodford or this http://www.tilersforums.com/users/19109-albums1235-23925/

 

[Muse2k8]

Yeah definitely replace with plasterboard or better yet backer board.

 

[Dougalogic]

cheers lads, good advice.
I'll rip out the wood and fix some backerboard which I already have. Can I attach it to the wall with bonding or mortar (not very deep cill and reveal so shouldn't be too heavy) or do I need some dry-wall addy? Or can I screw it onto the wall directly? Don't think it will fit on top of the wood.
The other question I have is that if I tile the wall face first to square the cill off, how so I get the horizontal tiles up to the same height? Bed them out?
As for the trim, which way round does it go or doesn't it matter?