Hardibacker boards and fibatape

[newnhambolton]

Do I have to tape the board joints with alkaline fibatape, if it is going to be tiled over?

 

[Goldberg]

Do the instructions say that you must?

 

[Richard C]

Yes; fill & tape the joints with tile adhesive just prior to tiling. I generally use Aquapanel boards but, as plastering is my main pastime, I use ordinary glass fibre reinforcing tape which I always have. Glass fibre is pretty inert so I can’t imagine the “specialist branded” tapes offer anything more than an unnecessary price hike!

You should also have “planned” the backer boards so the tile joint lines are spaced well away from the board joints; coinciding is not good!

Hope your using a decent trade tile adhesive & grout

 

[bathstyle]

According to the manufacturers, standard scrim tape will break down, therefore the alkaline tape should always be used.

 

[newnhambolton]

Thanks. I just wondered if I could have used ordinary fibatape but I guess I will be going to Topps to get the alkaline fibatape.

 

[Richard C]

Gypsum plaster & all cement based products are alkaline by nature. One would assume that manufacturers of a premium, GF reinforced plasterboard tape would not produce a product likely to fail under its influence .

I’ve been using the same GF reinforcing tape for many years, both for plastering & tiling applications. It doesn’t say it's “alkaline resistant” on the tin but I’ve never had any problems; but, for your peace of mind, buy the pucker “Alkaline resistant” tape & use that.

 

[joe-90]

I've never heard of scrim breaking down either. They try every trick in the book to make you buy their 'premium' stuff.

 

[bathstyle]

The only difference I see is that one is much thicker and not self adhesive.

I have phoned Knauf technical in the past and they muttered something about the continued moisture