Tile over old tile

[Downaski]

Hi everyone,

Is it okay to install new tile over old tile if the existing layer is still solid and well-adhered, or is it always better to remove the old tiles first?

Thanks in advance!

[TinyTool]

Hi!

Yes, it's generally okay to install new tile over old tile as long as the existing layer is solid, flat, and well-adhered with no cracks or loose spots. The old tile basically becomes your new subfloor. Just make sure to clean it thoroughly and scuff the surface with sandpaper or a grinder to help the new tile adhesive bond properly.

That said, there are a few things to keep in mind. Adding a second layer increases the floor height, which could affect transitions to other rooms, door clearances, or fixtures. Also, if there are any signs of moisture issues or instability in the original tile, it's better to remove it and start fresh.

So it’s not always necessary to remove the old tile, but it really depends on the condition of what’s already there and whether the added height will cause problems.

[Downaski]

Thanks! What is the best way to scuff the old tiles? Would regular sandpaper work, or do I need a specific tool for that?

[TinyTool]

A good way to scuff the old tiles is by using coarse sandpaper or a grinding tool to roughen the surface. For smaller areas, hand sanding can be enough, while larger spaces are usually easier to handle with a power tool. The main idea is to create some texture so the new tile adhesive can bond well. It's also important to clean the surface afterward to remove any dust or debris.

[Downaski]

Thanks! Would using a regular orbital sander work for this, or is there something more effective?

[TinyTool]

Yes, a regular orbital sander can work for scuffing old tile, especially for small to medium areas. Using coarse-grit sandpaper, like 40 or 60 grit, helps rough up the surface enough for the new tile adhesive to stick properly. It might take a bit longer compared to heavier tools, but it gets the job done for most situations.

If the tiles are very smooth or glossy, or if you're working on a larger area, a concrete grinder or an angle grinder with a diamond cup wheel will be more effective. These tools remove the glaze more quickly and create a rougher surface. Just be aware they can create a lot of dust, so good ventilation and a dust mask are important.

Whichever method you use, make sure to clean the surface thoroughly afterward to remove all dust and debris before tiling.

[Downaski]

Amazing, thanks for all the help!