Hi Guys need some help. Iv taken the iles up in my kitchen floor which has left me with a half concrete hal floor board surface to tile to. The concrete part itself is nice and solid and flat however it is slightly higher than the floor boards. I did want to use 6mm hardie board to keep the step around the thresholds to a minimum however given the slight height differences would this be spoosible still? I was thinking of just making up the height difference with adhesive but not sure if this is a good idea. I should also say this floor only needs to last a couple of years since we will be having an extension so wanted to keep costs to a min.

Any help would be appreciated

Ernie

Hi Ernie, you could make up the difference with a self levelling compound, Mapei Fibreplan will go up to 10mm and is suitable for wooden floors.

Hope that helps.

You can use the Hardie over the timber section of the floor as long as it is solid and you can then use leveller to bring the heights back in line. You will need to incorporate and expansion joint between the two substrates though.

Thanks guys. How would I go about incorporating an expansion joint Grumpy?

Ernie

Originally Posted by ern

Thanks guys. How would I go about incorporating an expansion joint Grumpy?

Ernie

You can either buy a purpose built joint from the likes of Schluter, or you can leave a gap at the joint when you self level and then fill with silicone...you need to transfer the joint through your tiling too!

THanks for the reply Grumpy, sorry I have not responded sooner but everything is on the back burner'cos of work.

I should have mentioned this before but the prob I have with the expansion joint is that the concrete and floor boards do not meet in a continuous line right across the floor the are mor like 2 interlocking L's if that makes sense. This floor has been down since the mid 80s so am hoping any and all settlement would have occured although do appreciate that movement is always occuring. Sjould also say the previouse tiles did crack but were more impact cracks as they had been dotted directly to the concrete / boards.

Would it be a big No No if I was to overboard the entire floor (Concrete and floorboards) with hardie board making up the difference in height with flexible adhesive? I have spoken to someone in topps who has suggested this would be ok although I would bow to your greater experience.

Assuming this is ok Im guessing that the concrete part would NOT need to be screwed as well as fixed with addy ??

As I say this is only temp for a couple of years and if I dont get this done soon she is going to stick me under the floor!!

Many thanks your (and anyone else's advice)


Ernie.

Has anyone got any comments on this ?

Ta - Ernie

Originally Posted by ern

Has anyone got any comments on this ?

Ta - Ernie

Ernie
you could put a movement joint around the edge if you wanted to, get in touch with trimline in surrey for their brochure.If the floor is coming up in a few years for an extention then why bother with all the expense? Get some flexible self leveller, toughen it up with grit sand (builders yard) and thats your problem solved, dont forget to acrylic bond everywhere.
Make sure the timber floor is solid and all screwed down

Originally Posted by ern

THanks for the reply Grumpy, sorry I have not responded sooner but everything is on the back burner'cos of work.

I should have mentioned this before but the prob I have with the expansion joint is that the concrete and floor boards do not meet in a continuous line right across the floor the are mor like 2 interlocking L's if that makes sense. This floor has been down since the mid 80s so am hoping any and all settlement would have occured although do appreciate that movement is always occuring. Sjould also say the previouse tiles did crack but were more impact cracks as they had been dotted directly to the concrete / boards.

Would it be a big No No if I was to overboard the entire floor (Concrete and floorboards) with hardie board making up the difference in height with flexible adhesive? I have spoken to someone in topps who has suggested this would be ok although I would bow to your greater experience.

Assuming this is ok Im guessing that the concrete part would NOT need to be screwed as well as fixed with addy ??

As I say this is only temp for a couple of years and if I dont get this done soon she is going to stick me under the floor!!

Many thanks your (and anyone else's advice)


Ernie.

Hi ern. The problem you will have with the Hardie board over the concrete is the fact that the board usually isn't flat and the adhesive doesn't have sufficient suction when wet to hold it down into place. You will need to screw and plug it into the screed to keep it flat.
I have to admit that i have on one occassion, very early in my tiling career doing exactly what you suggest and boarded straight over 2 different substrates, timber/screed without an expansion joint. To date there has been no problem with the floor, but I made very sure that the loadings on the floor were not great...i.e no children jumping up and down...they were an eldery, small framed couple! I also admit to now, waiting patiently for the call back for when the floor cracks......
It is now not something I will not advise or condone doing but the choice is yours. In an ideal world, you expansion joint should follow the line of where your two substrates meet but for you this may not be possible.

u could overboard it with PCI backerboard will stick straight bto the floor but would go 4 10mm :Pete

Hi earn, I have had a similar situation where the wooden boards are joining the concrete floor and not in a strait line also where there are pipes that have been boxed in timber and sunk into the screed, What i have done is, rake out abit of the screed or cut a bit of the end of the timber which ever is easiest just enough to give you a 2-3mm gap and then fill with silicone, then I have used a de-coupling membrane to bridge over the 2 different floor finishes. Then to bring up your floor level with a flexible self levelling compound, It has worked for me and I havent had a problem with it cracking.
But there may be more people on here with a better remedy.


Steve..

is it a T&G wood section or chipboard ern? or could you take up the wood section and replace with WBP plywood the same thickness as your concrete, then overlay with a ditra type decoupling membrane?

Thanks for all the responses guys I think the way to go falls somewhere between all the suggestions. I.e Board the floor boards with Hardie fill the diifeferent substrates with silicone as Peckers suggests, then use SLC. If I was to do this I guess the decoupling membrane would go above the SLC ?

However I was just wandering what PCI backerboard is as PJC suggests.

Thanks for your further advice.

Ernie

Construction Boards
Hope this helps :Pete