# Forum Home Renovation Tiling  Adhesive for fibre cement underlay

## Flyn

I'm tiling a large-ish area over a particle board floor.  Using the standard 6mm FC underlay, but the instructions say it needs to be glued down as well as nailed.  What's a suitable adhesive for this that I can buy in bulk?

----------


## shieldzy

hi flyn try using something like bostik alta seal or sika flex both are a bit of a pain to use as they are urethane meaning terps cleanup but both have great adhesion.

----------


## shieldzy

you can get both bostik and sika flex in bulk in sausage form.

----------


## Ricardito

Hmm I would be inclined to use a bonding agent that provides flexibility like Sika Flex Pro. That's my two cents
Check out with the guys at Concrete Protection they give good advice and reasonable prices Yes they do sel in bulk

----------


## Oldsaltoz

This sounds like overkill or misread instructions. 
The tile underlay is nailed down with extra close nails along the edges so it's not going to move. 
The joints between the sheets will be sealed when waterproofing so no risk there either. 
Are you sure the reference to sealing is not about the sheet joins.

----------


## Flyn

From the James Hardy ceramic tile underlay installation manual:  _Step 3 
Spread a suitable stud adhesive on the back of the underlay sheet with a
3mm notched trowel/spreader paying particular attention to the sheet
edges. If fixing to hardwood floors, adhesive is not necessary._

----------


## Scottythetiler

> This sounds like overkill or misread instructions. 
> The tile underlay is nailed down with extra close nails along the edges so it's not going to move. 
> The joints between the sheets will be sealed when waterproofing so no risk there either. 
> Are you sure the reference to sealing is not about the sheet joins.

  i have always used sika flex or liquid nails before nailing sheets down.

----------

