decoupling membrane over hardi

[judge]

Evening all, ive measured up 75 metres of suspended chipboard flooring split into four rooms at a property last night.ive allways used hardi to overboard wooden substrates but was wandering if a decoupling membrane could be used? Theres a good deal on at ctd and thought this way could possibly get my quote down on price and mats. The floors are deflection free and I will be securing boards before both options :smilewinkgrin:

 

[White Room]

What tiles will you be fixing....

 

[J Sid]

If it was me i would go with detra every time over hardie, especially if the floor is deflection free. Would be asking what is best to stick the detra to the chip board floor. CTD are the best price i have found.

 

[judge]

tiles will be 600 x 300 porc and 300 x 300 ceramics whitebeam.Was thinking of using weber spf for sticking membrane to surface.I am a little concerned about possible contamination in the chipboard as its been trafficed unprotected for about six months.(its not dirty but being its not mechanically fixed im a little concerned of the bond even if primed with apd. Could it be lightly sanded before prime ?)

 

[J Sid]

A call to schluter in the morning my help.

 

[judge]

Ill give them a bell tomoz.Cheers

 

[White Room]

tiles will be 600 x 300 porc and 300 x 300 ceramics whitebeam.Was thinking of using weber spf for sticking membrane to surface.I am a little concerned about possible contamination in the chipboard as its been trafficed unprotected for about six months.(its not dirty but being its not mechanically fixed im a little concerned of the bond even if primed with apd. Could it be lightly sanded before prime ?)

Hardie actually say use a non flexi adhesive under the boards then mechanically fixed, I use screwfix turbo gold 25mm screws...

 

[charlie1]

Hi judge, decoupling membrane and hardie are different things for different types of movement. If your floor is deflection free then great, put down 6 mm hardie! If however as I suspect , you have concerns with lateral movement then use a decoupler.

 

[Houston]

as above, decoupling membrane for lateral movement

 

[Stef]

I would just overboard with Hardie 6mm,
I think for the tiles you are fitting then Ditra is a bit overkill.
I don't think you really get a lot of lateral movement in wooden floors if they are deflection free to start with.
It's normally too much bounce in a wooden floor that will affect the tiles.
CTD are doing a great deal on Ditra so it's what ever works out cheaper..

 

[judge]

So i can work out a price for the decoupler,how much extra addy will i use sticking the membrane down and then filling the surface? Is it best to fill the surface and let dry or fill it as you lay the tile ? Theres only one other quote for this job and the customer told me the other tiler was going to use a "highly flexible" adehsive and lay straight to the chipboard surface !!!!!!!!!. Ive told the customer my quote is going to be more expensive because I will be installing the tile correctly so i want to be as competitive as possible with this quote.(Theres also 2 bathrooms and 2 onsuites for wall tiling aswell

 

[J Sid]

I work on 1 20kg bag of adh will do 5 m2 to stick detra down and 1 20 kg bag to do 2 to 3 m2 to stick tiles and i always fill holes and lay at the same time, this includes back buttering the tiles.

 

[judge]

thanks jul,I can sort a quote out now