3 - 4 mm dip in floor

[Aspesim]

Hi guys
I’m going to install 6mm Hardie-Backer Board over 18mm ply, however there seems to be a dip across the 2.0m room 3/4mm at is lowest point feathering off as it moves out from the middle.

As stated the floor is ply (two sheets with a 3mm gap between them) would I need to use SLC or would Bal addy be sufficient to level the floor?
Would I need to level the floor before the 6mm HBB’s?

As usual thanks for you help and advise.
Aspesim

 

[Ian]

A couple of ways, use SLC before fitting the HB or use a thick bed adhesive when fitting your tiles. My preference would be to sort the dip before fitting the HB, not a fan of packing tiles out too much, having said that, 3/4mm isn't that much to be fair.

 

[nybor62]

i would go with slc to remove the dip imo

 

[AliGage]

4mm is not much at all to build up. If it's ply and then hardie as well. Your not likely to be using a huge trowel depth.

I think you could comfortably build this up when tiling, just don't forget it's there

 

[andyb1]

Build it up with addy.

 

[Aspesim]

Thanks Guys
Ok it seems 2 & 2?

Would I have to treat the ply before laying the SLC (as most of it is water)? Any make of SLC? What would I use between the 3mm gap in the ply?
Addy seems easier but what is best ?

Any more for advise on SLC or Addy Welcomed plus any other advise is always welcome here!

Thanks Guys
Aspesim

 

[Martyn Leeds]

If it were me, I'd fix the ply and hardi as usual, then mark out the low patch, & then skim it with my rapid adhesive prior to getting started on the actual tiling...

 

[kilty55]

i would pack it out also

 

[Aspesim]

Thanks Martyn I quite like that idea.

Now I have two for SLC, two for Addy and now two for packing!!!

 

[Peter]

Wish I did more floors which only had a 4mm dip over 2m. Usually dealing with 10mm over 0.5m :lol: