Update! I really want tiled flooring...but I have floating chipboard

lambo28

UPDATE:

I spent today ripping up the old/rotting chipboard flooring down to the concrete substrate. Now the question is, is there a minimum thickness to build the timber frame? Would I screw the timber frame through the timber and into the concrete. The original floor is a total of 53mm (18mm chipboard and 35mm polystrene) which is quite shallow. Also I have no joists at all currently.

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Hello all!

I'm currently in the process of renovating my kitchen, I'm so excited! I bought my cabinets and worktops (Ikea Abstrakt White and walnut effect worktop btw). However, I want to have floor tiles this time not vinyl to give it that edge.

The problem is: I have floating chipboard flooring (I think it's 18mm chipboard with a clear damp proof sheet and polystyrene underneath). I've done a bit of research on the net but there seems to be conflicting information so some help would be appreciated.

To go about doing this, i guess I have 3 options

1) Overboard with WBP 12mm ply.

2) Support the area with timber joists and noggins by cutting parts of the polystrene and then chipboard the area and finally overboard with WBP 12mm ply.

3) Rip out the chipboard and polystyrene and fill the whole area with concrete (is that even possible?)

Currently, areas of the chipboard I have has rotten through so I'll have to replace these areas even if I can't tile (with T & G chipboard flooring). I don't think the current chipboard I have on the floor is T & G because it does not have a green appearance. Any precautions I should take?

Do I have any other options?

Thanks for reading.

Alan_M_2

In order of preference:-

1/ Pull it all up and get the area screeded. This is not "concrete" it's sand/cement and really needs to be a minimum 70mm thick to be stable. Fit your tiles safe in the knowledge they will not go anywhere.

2/ Fit timber joists and replace the chipboard with 25mm WBP ply supporting all joins. Probably as expensive as option one and not as stable.

3/ Replace the rotten bits and use something other than tiles, such as lino or laminate etc. (far cheaper).

4/ Do not allow anyone to talk you into overboarding what you have there or using an orange matting called Ditra Matting. It is not suitable and not designed for this purpose.

vivatifosi

When we did ours we did option 2 in Alan's list. It was the right solution for us, even though it took an age to do because our kitchen is north facing, unheated other than a small plinth heater and can get very cold, the last thing we needed was a concrete floor. The floor has now been down a few years and still looks great. Many of our neighbours have gone for concrete, but their house orientation is not necessarily the same.

lambo28

If I go for option 2, how far apart do I put the timber frame in? Any tips?

ormus

do not overboard. clear up/out the present mess first.
im assuming you already have joists underneath the present suspended floor?
install 1 inch ply, or three quarter inch.
and use flexible adhesive for the tiles.

Alan_M_2

lambo28 wrote: »

If I go for option 2, how far apart do I put the timber frame in? Any tips?

600mm centres should work out very nicely on 2400mm x 1200mm boards and shouldn't leave any unsupported joins.

Screw these down with 60mm screws at 200mm centres over all joists.

Everything should then be nice and stable, and you can insulate between the joists.

Spend time packing out any low areas under the joists to remove any "spring" from the floor.

keystone

At 600 centres I'd be putting lots of noggins in too.

Cheers

bails1964

keystone wrote: »

At 600 centres I'd be putting lots of noggins in too.

Cheers

agreed, for 2400 x 1200 centres should be 400mm.

tony6403

18mm flooring grade chipboard can be laid over joists at 400mm centres.
If the joists are at 600mm centres then 22mm flooring grade chipboard should be used.
Noggins are not generally used in floor construction - strutting is used but this is for rigidity and not to fix board edges (which interlock and are glued).
No harm in adding noggins but not necessary if normal standards are used.

keystone

Thanks Tony but you missed my point whereas bails didn't. Never mind I was being a tad obscure.

Why are you recommending chipboard flooring as the OP wants to tile?

Cheers

lambo28

Thanks everyone for the help! My kitchen is north facing (so screeding might make my kitchen too cold) and actually quite small (3220mm by 1920mm) so I might have trouble with 2400 by 1200mm ply and how can I do 600mm centres? Also, I don't think any joists exist at present, all of the current chipboard is suspended by polystrene.

Oh why did they not build 'proper' flooring in when the house was built? Cost cutting? Btw house built around 1988.