Replacing laminate flooring with ceramic tiles - increase in height

[bangerdude]

Hi,

She who must be obeyed has instructed that the existing laminate flooring in the kitchen must be replaced with ceramic tiles, but I think we have an issue with the height available under the existing worktops.

The existing flooring is laminate (6mm) laid over fibre underlay (6mm) which is directly over floor boards. The floor boards are a bit uneven, hence the use of the fibre underlay. There is a gap of approx 8mm between an existing dishwasher and the under side of the worktop.

The advice I have received is that I will need to lay 18mm plywood over the floor boards in order to give a stable level surface which will not flex too much. On top of that will be adhesive and ceramic tiles giving an additional depth of approx 8 - 10mm.

So the issue is that I have available space of 6 + 6 + 8 = 20mm and would like to fit ceramic tiles, which will require an available depth of 18 + 10 = 28mm (plus a bit to allow the dishwasher to be fitted under.

Is there anything I can do to make it all fit? I am unable to easily move the worktops up as there are ceramic wall tiles directly above, plus I'd rather avoid the need to modify sink and gas hob pipework if at all possible.

Is there anything which is narrower which can be used in place of the ply? Or any other options?

Lifting the floorboards and replacing with chipboard isn't really an option as this would require removal of the units etc.

Thanks for your help.

[peckers]

Your only real option is to jack the units up or to lift the work tops as you already realize. Theres no easy answer unless off course you really treat the wife and install a new kitchen too.

[Mike]

if it's an intergrated dishwasher it should have enough gap under it to accomodate the tiles. i usually need to put wood under the feet of dishwashers to get it to meet the bottom of the worktop (870mm) as there's never enough adjustment on the feet. may be different if you have a washing machine tho

[bangerdude]

I had thought of an integrated washer but would rather avoid the additional expense - but it looks like it is probably the easiest answer. Jacking the worktops up seems like a major pain, as the worktop in question is L shaped with sink and hob fitted, with tiling along the full length.

Thanks for your help.

[simmy08]

hi,I had the same problem.I pulled up the floorboards and Strenghtened the joists by putting in noggin's/dwang's every 300mm.I did this to ensure the floor was strong enough. I primed the floor and siliconed any gaps. I then used Bal single part fast flex to fix the tiles with a solid bed trowel to fix the tiles, making sure i back skimmed and skimming the floor also as i went. Ive had the floor down for 2 years now with a washing machine /dryer vibrating over it and i have no cracks or any problems. Im not saying this is the best or cheapest way but if you are willing to take a slight risk, there are other ways. I called technical helpline before doing anything to make sure i was doing everything their way so it could be guaranteed.

[Bri]

Am I missing something here, or can a 6mm cement board not be used? I've read the opening post twice and there is no mention of deflection, so surely overboarding with a 6mm hardie 250 or similar plus the tile, will give the op the 18mm floor which will allow his dishwasher to fit under the worktop.

[simmy08]

or use 6mm cement board.....haha

[russ1980]

Just what i was thinking 6mm cement board if it was me

[peckers]

Am I missing something here, or can a 6mm cement board not be used? I've read the opening post twice and there is no mention of deflection, so surely overboarding with a 6mm hardie 250 or similar plus the tile, will give the op the 18mm floor which will allow his dishwasher to fit under the worktop.

This could be done i thought that there might be concern over the deflection in the floor as he has been advised that 18mm ply should be used. also in his post he has stated that " The floor boards are a bit uneven, hence the use of the fibre underlay." It could be that the 6mm hardi backer would not have enough support all over if this is the case then there might be an error here. Hardi would be a better option then ply due to its tiling properties but it shouldnt be used to strengthen a wooden if this is the case?
He could sand the floor to make it flat (remove the undulations in the floor boards etc) and then if there is no deflection or movement in the wooden floor then hardi can be used as long as he still has the height clearence he needs..

[bangerdude]

Am I missing something here, or can a 6mm cement board not be used? I've read the opening post twice and there is no mention of deflection, so surely overboarding with a 6mm hardie 250 or similar plus the tile, will give the op the 18mm floor which will allow his dishwasher to fit under the worktop.

Would the cement board be ok where the underlying floor is not level? Half way across the space to be tiled is an area where an internal wall was removed, and there is a step of quite a few milimetres between the boards on the two sides - definitely more than the 3mm in 400 recommended in the hardiebacker data sheet. Hardiebacker DL Leaflet 1110.pdf The rest of the floor isn't perfectly level as the house is from the 1930s (and hence the use of the thick underlay for the laminate) but there are no other single large steps across the area.

For the laminate I built it up using thin hardboard so that there wasn't a single big step between the two sides. Is this ok for cement board? I've never used it before so I am not sure how flexible it is - I suspect as it is cementitious it is probably not massively flexible!

Thanks for your help.

Jon

[peckers]

Hardi backer should be bedded into flexible tile adhesive and then screwed down, the adhesive will take up minor differences in the levels other then this you can apply self levelling products to overcome the uneveness and the un levelness. But you dont have much height to work with in the first place?
Hardi isnt flexible and needs to be supported over its entire surface.

[jay]

Might help if you post some pics of the floor esp the areas you have mentioned