Plasterboard & Rapid Set

[GazTech]

It has been asked often.." can I dot & dab plasterboard using rapid set"?
The answer is yes but there is a condition ! Exactly the same way as Gypsum plaster ( Skim coat ) has to be separated from contact with cement based powders, then so does plasterboard. The reason being a reaction called Ettringite failure, with the use of primer such as APD or Bal bond creating a barrier to stop this reaction occurring is needed. You may say, "but plasterboard has paper covering it to protect it" , this isn't a good enough protection, for when the moisture from the adhesive penetrates the board, then this is where through migration the Ettringite chrystals can form and eventually ( but not always ) result in de-bonding of the two surfaces. For a more comprehensive guide to this occurance I attach sWe's superb guide...Gaz
sWe's guides

[beanz]

Are you just trying to give Deano sleepless nights???

[redlee]

Is this for all cement based adhesives?? because granfix say dont prime plasterboard on there bags of flexible rapidset.

[GazTech]

Is this for all cement based adhesives?? because granfix say dont prime plasterboard on there bags of flexible rapidset.

You would have to speak to their tech dept for the reasons why Lee. Bal always recommend 2 coats of apd before tiling onto plasterboard with any of our cement based products, for the reasons I have posted....Gaz

[redlee]

Suppose it can't do any harm priming anyway?

[GazTech]

Suppose it can't do any harm priming anyway?

No it dosn't, the worst that can happen is that it slows down the setting times of tubbed adhesive slightly with it being water dispersal. But in most cases with dispersal adhesive there is no need to prime because it is acrylic not cement based, so no reaction between the two which could lead to failure.......Gaz

[brian c]

Good post Gaz m8.

[deanotile]

It has been asked often.." can I dot & dab plasterboard using rapid set"?
The answer is yes but there is a condition ! Exactly the same way as Gypsum plaster ( Skim coat ) has to be separated from contact with cement based powders, then so does plasterboard. The reason being a reaction called Ettringite failure, with the use of primer such as APD or Bal bond creating a barrier to stop this reaction occurring is needed. You may say, "but plasterboard has paper covering it to protect it" , this isn't a good enough protection, for when the moisture from the adhesive penetrates the board, then this is where through migration the Ettringite chrystals can form and eventually ( but not always ) result in de-bonding of the two surfaces. For a more comprehensive guide to this occurance I attach sWe's superb guide...Gaz
sWe's guides

Dose BAL guarantee the product when it is used in this way I think not so not such a good post after all gaz. Maybe you tech boys at BAL should go on a course at Webber or mapei just a thought.

[GazTech]

Dose BAL guarantee the product when it is used in this way I think not so not such a good post after all gaz. Maybe you tech boys at BAL should go on a course at Webber or mapei just a thought.

Obviously not if you don't agree..

[Dan]

Steady-on lads.