Tiling on particle board

[Gib Bogle]

We are planning to replace the tiling on the bathroom floor in our house. The particle board floor has already suffered a bit of water damage in one spot (this I have attended to with a two-pot epoxy sealer, which has soaked right in and made that patch very strong) therefore I intend to make sure that the whole surface is properly prepared before laying the new tiles. I could use the two-pot treatment, but it would turn out quite expensive. I'd be grateful for suggestions about the most suitable type of product to use for this purpose. Thanks.

[John Stumbles]

Ha'porth of tar :-)

Unless you're just slapping down some cheap tiles to tart up and sell the place I'd really, *really* rip up the chipboard and put down at least WBP ply to tile onto. Water *will* get past your tiles (or more to the point, grout) and the chipboard *will* swell up and probably bugger up the tiling.

[Pete Verdon]

Granted tiling directly onto chipboard doesn't sound too clever, but could one not apply a suitable membrane (either just waterproof, or something clever like Ditra) or boards (Marmox etc)?

Pete

[Gib Bogle]

"Will", but when? This tile has been down for 35 years, and the damage to the untreated chipboard is slight. I'm guessing that with a waterproof treatment the floor will last a lot longer. Although it's not cheap, using the sealer I referred to would cost much less than replacing the flooring. This "Penetrating Epoxy Primer" is claimed "to penetrate and saturate the timber" and to have "waterproofing qualities suitable for marine use".

[The Natural Philosopher]

Justs retile.

Tiles are waterproof.

Grout is not COMPLETELY water proof, it its in a puddle, water will eventually seep through.

If it does you have bigger problems than soggy chip tho.

[Stuart Noble]

Anything that raises the level of the floor gives you problems at doorways, wc bowls etc. I'd go with the sealer. Polyester is cheap and probably waterproof enough for this application.

[PeterK]

One advertised solution is something that sounds/spells like "no more ply" AFAIK it is 6mm cement fibre board in 2'x3' sheets that are fixed with polyurethane glue and screws and cost £10? /sheet. I wonder if its the same as "RCM Multipupose fibre cement board - A high performance cellulose fibre cement sheet which can be used in an extensive range of application both internally and externally. Key Benefits: Excellent weathering properties, high tensile strength, high MoE, smooth finish for paint, excellent acoustic performance. A very strong versatile board." A 6mm 8x4 sheet being £15 on their price list at

This board should address water issues but also glued & screwed should add significant rigidity to a chipboard floor.

Peterk

[newshound]

Is that flexible enough not to crack when put down on a floor? I'm thinking particularly of floors in old properties where there may be a bit of movement in the odd joist.

[PeterK]

I presume that is where the polyurethane glue comes in since it foams into gaps during setting and where there are gaps the foam would compress/stretch if the underlying board moved . I wouldn't like to try and remove stuck down boards - I've been caught once with the glue got some on one hand transferred it to the other without noticing and ended up with the stuff stuck to my hands for 3 days! Fibre cement board is pretty tough stuff but does have some flexibilty and I think it would stand significant stress. I'm tempted to ring RMC and ask why aquapanel, hadiebacker etc. are the same product or what is the difference.

PeterK

[The Natural Philosopher]

If you have a floor like that do not even THINK of tiling it without=20 stiffening it.