cutting wall tiles on the wall

gamston

hi 
i need to replace a wooden window with a upvc one (so it matches the others we have) the wooden window is 55mm wide and new upvc one is 70mm wide so i need to cut the wall tiles back around 15mm, i've got a few spares but not enough to replace them all around  the window frame
don't think i will have enough control over an angle grinder to cut the tiles back, did try a battery rotary tool but it kept stopping, has anyone used a plunge saw to cut tiles ? don't want to buy one and find it doesn't work
anybody got any tips to cut tiles back on the wall

531063

https://www.amazon.co.uk/Katsu-Mini-Angle-Grinder-75mm/dp/B00KDEVQQ0  bit more controllable than a 115mm

grumbler

Do you mean 70 mm thick, not wide, and is it the tiles inside the window opening that you want to cut?

Personally, I'do this with an angle grinder, but yes, you can do it with a compact hand saw and a guide. Mine has a diamond disk in the set. I would use a wooden plank screwed to the wall as a guide (or glued with a thermo-glue). However, if it's inside the window opening, I don't see how you can do this in the corners with either an angle grinder or a saw.

gamston

yes 70mm thick 
I'll think about that 3" angle grinder if i can get diamond disc to fit, go a few spare tiles in case I need them
I may be able to make a wooden former to guide/protect the tiles and use large G-clamps to hold it in place

Belenus

Has the new window been made yet?

If not, you could add some plain tiles (or other suitable material such as PVC) of the same thickness as the current tiles to give a flat wall surface for the new window. The new window would hide the plain tiles. You would need to make sure it was properly sealed against water ingress.

That would mean the new window is slightly narrower, by the thickness of two tiles. Would that be an issue?

Alternatively, ask the window supplier if it is possible to make the window with stepped sides. It might be possible to cut a 15mm deep section off the sides of the window without compromising it.

I'm not an expert so please get expert advice on the feasibility of those suggestions.

Belenus

grumbler said:....Personally, I'do this with an angle grinder, but yes, you can do it with a compact hand saw and a guide. Mine has a diamond disk in the set. I would use a wooden plank screwed to the wall as a guide (or glued with a thermo-glue). However, if it's inside the window opening, I don't see how you can do this in the corners with either an angle grinder or a saw.

A sharp chisel used carefully and gently might sort out the corners.

gamston

think making the window small to fit inside the tiles would not look right
did look for smaller window profiles but can't see profiles to suit the rest of the upvc frames i have
have thought about smaller windows (10mm) and using 10mm frame extenters that i could cut out the 15mm i need then cover any gap with upvc trims