Can new bathroom floor tiles be laid on top of original tile cement which is stuck fast on chipboard?

Best to try get most of it up and buff the floor down a bit, don't tile onto chipboard either there's too much movement, if the floor is solid underneath ply over the chipboard.

Use a smallish sds drill on hammer only,with a wide curved chisel bit (de Walt or Bosch make them) then just go gently and it will remove the adhesive no problem at all. Then hardy backer board to stabilise. Wear all the appropriate PPE though. It gets noisy and dusty.

I would not advise retiling onto chipboard, my advice is to remove as much of the adhesive as possible then cover the chipboard with 6mm cement backer board glued (with floor tile adhesive) and screwed, making this a far better substrate to work on and you will not have any issue of cracked tiles or grout.

It might be more advisable to remove the chip board and lay new although it may be underneath the toilet and sink. Have you tried to remove the adhesive, I would probably said it would be a bal flexible adhesive which will come up with hard work and possible a hammer drill Me personally would probably take up old chip board, chip board is not the best to use in a bathroom backer boards are much better. You also may struggle to cut round the toilet and sink as even some tilers can find it difficult, also it will be more difficult for an amateur to tile over adhesive, you could use a suitable levelling compound, also remember this will make for a bigger step to deal with at the door

In short yes they can, however I would not personally lay any tiles directly onto chipboard although I accept some tilers do without any problems of movement, cracking etc. I would over lay the chipboard with ply or a hardybacker, prime and then tile.

Hi murphy_31 you need to chip all old tile cement off the surface as this will give you a solid base to lay your new tiles to the floor. If you are to leave the old tile cement on the floor it will make your base uneven and will cause your new tiles to lift when walking on them and also cause your grout to crack if it is not removed. Once you have chiped the old tile cement off give your floor a good brush to remove dust. I would recommend laying 9mm ply wood on top of your chip board and use a flexable adhesive when laying your new tiles aswel.

Yes is the short answer. However, before relaying the replacement ceramic floor tiles vacuum all dust, coat with unibond and use a 10mm notched trowel to compensate for minor discrepencies in floor level.