Help!: Time served advice needed please.

[canny]

Hi All,

I just need time served views on this one please.

I have a small shower room about 2mx2m. Very light traffic.One person at a time.Cellar below wooden floor

What i have done......................

Due to the excellent condition of the wooden floor, which is flat, very rigid,due to the short span, tightly laid without any gaps.I have added extra screws next to the original nails to secure the boards even more so, (only for peace of mind, due to not using an overlay of plywood)and then layed floor tiles 300mmx300mm on a fast set flexible waterproof adhesive (profix powder Grey, 20mm ribbed trowel). I am also going to put a flexi additive into the grout as well.

I know i should have overlaid with at least a 12mm wbp ply, but wanted to avoid a trip hazzard to the original remaining floor and felt as a builder, the floor was in excellent condition, sound, rigid and secure..

The question i have is, has anyone else done the same thing under the same conditions and had a trouble free job. Asking other trade guys locally has given me mixed views. I have tried speaking to tec guys from suppliers but they will only quote company guidelines, always trying to avoid a risk of a claim, not balance of probability opinons.

My gut feeling is it will be fine, but i would like to know others experiences on similar experience.

Many thanks

[brian c]

did you put a flexi additive in the adhesive?if you did then it might be ok but if not then imo it wont last forever.

[Colour Republic]

What condition were the boards in? i.e dusty, varnished etc etc How did you prep the floor other than screwing them down mate?

[whitebeam]

I take were talking floor boards

[timeless john]

4sq mts of tiles fixed direct to tounge and groove floorboards - I reckon about 3 months then they'll crack along most of the boards!
If the boards were that well fixed you could have used a uncoupling membrane (ditra/dura) which would have added 3mm to your finished floor height and given you a top job for approx £55-00 extra!
Still it will give someone else a job to do after christmas.

[brian c]

i hope so and not chipboard!

[canny]

The wooden floorboards were in excellent condition,clean, very little dust and not varnised . I washed the floor down then primed the floorboards with Bal primer. To be hornest its the best floor i have come across in years. It looks look more like one piece of timber biscuit jointed together. I only added extra screws as i felt umcomfortable about not using an over lay.But as i said i had to avoid a trip hazzard.

[doug boardley]

I'm with Timeless John on this one, to much potential movement imo

[marke]

sort of wait and see this one !! would have advised 2 part flexi at least mate have used that before to good effect but even then not directly onto the boards . ask santa cross his fingers for you

[canny]

I have even got the meat and two veg crossed!!

[canny]

Do you think will it crack along grout lines or dislodge the tiles?

[whitebeam]

Done it once, never again.

Once bitten twice shy

[doug boardley]

Do you think will it crack along grout lines or dislodge the tiles?

along the floorbard joints

[macten]

4sq mts of tiles fixed direct to tounge and groove floorboards - I reckon about 3 months then they'll crack along most of the boards!
If the boards were that well fixed you could have used a uncoupling membrane (ditra/dura) which would have added 3mm to your finished floor height and given you a top job for approx £55-00 extra!
Still it will give someone else a job to do after christmas.

Does Ditra actually help in this situation? - thought it was for green screeds and eliminating lateral movement - not bounce

[whitebeam]

I know of a tiler who uses ditra on floor board all the time

[macten]

you maybe okay - seen a lot worst fixed with no sign of problems when ripping out.
But we do this everyday and also see a lot of problems because of just this very scenario.
Bit of a lottery - the small dimensions involved may save you... or may not

[canny]

Whats your view. I know i have been a nob, however i have had some guys say it will last 5+ years other just suck their gums and shake their heads.If it does move will it just crack the grout or lift the tiles?

[macten]

I know of a tiler who uses ditra on floor board all the time

But it's use isn't to strengthen floors though is it.

[RockCeramics]

just to say my bit of info.
When fixing 18mm marine ply extend past the freshold approx 12"-16" then shamfer the end to give you a slight ramp and you will not any trp hazzards there will be a bit more work invovled but a professional job will be acheived.

[whitebeam]

Oh no, just lateral movement mate

[macten]

Chances are it will be okay with such a small floor.
If not, and there's no telling WHEN problems arise - but if they do you will need to take them all up and start again with overlay (6mm cement board is a good choice if you want to minimise height differences.)
If not then try your luck with a 2 part flexi.
If it was a customer of mine I would go 6mm NMP and flexi addy

[canny]

what if i were to add extra noggins to the underside of the floor (Cellar)

[macten]

Wouldn't do any good as the noggins will only be effective if the boards are screwed into them - and you can't do that as the floor is already tiled

[canny]

How about screwing batterns to the under side of the floorboards, between joists to restrict any possible movement from the underside

[canny]

what if i were to add extra noggins to the underside of the floor (Cellar)

[macten]

Won't really help now to be honest.
Just wait and see is your best bet now.

[Prem Tiler]

Wood floor boards, as in wood as in natural breathing material that exspands and shrinks in humid, dry conditions, as in wood that oftern warps even in the oldest most exspencive of timber used to make £5000 gutiar necks?

Bolt the door after the horse has bolted comes to mind.

Oh and I'm not time served just having a bash at it.

[canny]

Here's one from outside the box. How about laminating with glue and screws some ply onto the spaces underneath the floorboards between the exsisting noggins so in theory reducing movement and given floor a more rigid structure.

[canny]

And at me! As i've said i have already admitted NOB status, just looking for a life line.Also, being in the building trade i have seen many a poorly preped job stand the test of time............best one, wall tiles fixed to 6mm hardboard fixed onto noggins. Was sound as a pound

[doug boardley]

canny, you've asked advice and we're trying to advise and help you with honest opinions, you may be lucky and it survives, but the general consenus is that retro- prepping will not really help. Swallow the bitter pill and learn from it mate