No it isn't advisable...both floors are floating floors and both will be moving (expanding/contracting differently)...could cause problems, when they start moving against each other.

Tiles dont float.

Also you may have to cut doors, architraves etc down, which then will be too short if you ever decide to change it again.

But it comes up easy...no stress, little mess :)

There is nothing wrong with putting one panel on another apart from the height. I wouldn't say this is not done properly but it will definitely be a problem with shaving doors etc as you guys said before. I had this once, that customer wanted me to lay 2 layers of panel flooring because he had 2 rooms done by someone before and the level was not right in other rooms. I have used 9mm ply in 2 other rooms. just think about the square meters I had to charge for!! :) not recommended by me personally.

Probably best to take old up first.If a jobs worth doing its worth doing properly

You can but be aware that any doors you have might need to be cut smaller, because your raising the floor.

Its better and easier to take old floor up, shouldn't take long and you can dispose of it at your local tip.

no laminate will expand and retract there will probably blow

As a professional flooring installer, i say it is always best to go back to the subfloor. I.e. remove the existing floor covering and start again. As a few have said the height would be a factor, but the main thing is expansion....and can you be 100% sure the existing floor has been laid perfectly and is completely sound? Its not worth the risk of something going wrong.

hi,wood no as it can sweat and buckle , laminate yes as i have done this at least 10 times over the past few years and the only reason against this is the height difference/finishing issues with adjoining flooring [carpets especially] if you use a clic laminate and do have problems u can take up both floors and relay the new one, good luck lance

Yes you can but there's no point the floor is so easy to take up with no mess you would make moor mess going over it as you would need to shave all doors and loose your skirts

You should always take the old floor up as it’s a floating floor. Best to do a job right first time

Take the old floor up, if a so called professional fitter came to mine and said it was OK to put laminate on top of laminate then I would show him the way out immediately

Always best to uplift (especially Laminate as it can be problematic)and check the subfloor, it doesn’t take long and you can be sure everything is as it should be.

As with all the other replies, technically the flooring should be lifted this is the correct action to take. However in the past I did do this for a customer at their request and only after explaining the implications. Their sub-floor was uneven I recommended the old flooring be lifted and they should ply the sub floor however as this would add to the cost of the job, they requested I lay the flooring on top of existing flooring at their own risk. I have returned a year later to fit an additional floor in their house and there had been no issues.

You can do this as long as the flooring that is down first is well put down saves some mess
Only down fall
Can cause problems if both floors move
Doors needing cut archs needing cut
Going back to the original floor would have big gaps at the door bottoms
Better just keeping yourself right and lifting the floor and starting again
Keeps you right In the long run

It’s best to take the old flooring up and then it will be done right. If the flooring below moves a lot from the one on top it could cause problems and it’s not a proper job.

Go back to your subfloor not advisable to lay on top as many have previously said height expansion etc comes into play

It is not recommended.

Personally if you would like a professional job I would take the old laminate up, it doesn’t create to much mess disposing of the old. If you kept the old laminate down all you would create is movement in the flooring itself. Also laying on top creates more work as I can imagine you would need the doors shaved etc... I also wouldn’t advise laying on top of old tiles for future projects.