fixing hardibacker 250 to a highly glossed floor

[kilty55]

lo all,ive fixed hardi boards numerous times with addy and screws to t and g boards,,this job i have looked at has an old painted border on it...seems to have been done profesionally a long time ago and has a very glossy varnish over the boards,,what do you guys/gals reckon will it be safe enough to fix as per normal over these floor boards?

 

[doug boardley]

Jamie, I'd be inclined to run a belt sander (or orbital) over it to remove the varnish

 

[White Room]

Same as Doug, rough the surface before fixing

 

[kilty55]

cheers doug i was thinking this to rough it up/key the boards again

 

[DHTiling]

The adhesive is just to take up voids not adhere it..

 

[kilty55]

surely it also helps it more solid on the floor tho dave?

 

[DHTiling]

why..?.. the screws are to pull the board down and adhesive fills voids/// not rocket science..:smilewinkgrin:

 

[TheWrightTiler]

am with dave on this, but if u can be fussed roughing up then cool

andy

 

[White Room]

If the adhesive dos'nt stick to the floor it's only the screws holding the board IMO

 

[jay]

If the adhesive dos'nt stick to the floor it's only the screws holding the board IMO

yes thats right adh is mainly to fill hollows (cuped floorboards ect) it sticks to backer board and screws do the holding thats why screws are better than nails

 

[doug boardley]

I was thinking more along the lines of primer soaking into t and g, :shy:

 

[DHTiling]

It states on the HB site that the adhesive is just to take up voids in the substrate,,

 

[White Room]

yes thats right adh is mainly to fill hollows (cuped floorboards ect) it sticks to backer board and screws do the holding thats why screws are better than nails

I actually forgot to screw one to the floor but used sbr with the addy and it stuck, I was advised from a shop to nail and adhesive under the hardie then remove nails:yikes:

 

[doug boardley]

It states on the HB site that the adhesive is just to take up voids in the substrate,,

but you know us guys from plastering backgrounds are happy to rough it up:lol:

 

[DHTiling]

If you like it ruff, who am i to disagree..:lol:

 

[jay]

I actually forgot to screw one to the floor but used sbr with the addy and it stuck, I was advised from a shop to nail and adhesive under the hardie then remove nails:yikes:

wow with advice like that you don't need enemies fingers crossed for you

its a bit like plaster boarding a ceiling years back they said just use stab (adh) and nails to be removed when dry
after many failures they now recommend screwing as well

just to add you nail through a small scrap piece of plasterboard into new ceiling when dry remove if you understand/////

 

[White Room]

Thats scary:yikes::yikes:

 

[jay]

yes and in the end insurance companys stoped paying out😳

 

[White Room]

Was that onto timber joists jay

 

[jay]

yes strait on to timber might be one of the reasons they use metal battons now:8:

 

[White Room]

Never used an adhesive onto joists:yikes:

 

[jay]

Broken Link Removed - Cached - Similar

cant seem to get csr one to work deffo recomend it with screws

 

[kilty55]

cheers for the advice guys

thing is dont hardie say you can use clout nails to fix? if this is the case and the addy didnt stick you could find yourself in hot water


also about the addy taking up the voids,,,thats fine but if it isnt stuck the the sub floor surely that stil leaves a sligght space for moverment?

 

[jay]

cheers for the advice guys

thing is dont hardie say you can use clout nails to fix? if this is the case and the addy didnt stick you could find yourself in hot water


also about the addy taking up the voids,,,thats fine but if it isnt stuck the the sub floor surely that stil leaves a sligght space for moverment?

you can use clouts as stated but screws are far better
addy between floor and sheeting shouldnt move if its screwed right its just used to keep sheeting flat and not taking the shape of the floor

hope that helps

 

[Rob Z]

The CV here in north America is that you should use an unmodified thinset (no latex, no polymers, no additives) under the panels. As Dave and Jay said, that material is there to just fill the voids. There has been a lot of testing at the lab for Tile Council of North America that has demonstratred that the floor is actually better constructed for tile if the cbu's are NOT glued to the floor with adhesive (and only fastened with screws or nails).