strength of everbuild dryfix

[arbitrary]

Everbuild's dryfix looks to be a convenient alternative to dot and dab for fixing plasterboard to walls. However, I can't find any info on how strong it is - can I then tile onto the plasterboard without risking the whole sheet coming loose? Should I supplement it with mechanical fasteners?

 

[1john]

it is expanding foam, it is strong, you also end up with a continual bond around the edges of the board and at 400mm centers, I think it may be stronger than D&D for the fact that the back of the board hasnt got wet muck on it which could be more likely to cause the paper to de-laminate from the board, thats just my take on it.

 

[arbitrary]

1John, thanks for your post. I should add that I stuck a test piece on the wall roughly 2 feet by 4 feet. 48 hours later I was able to carefully remove the entire piece from the wall without breaking it by using a wallpaper stripping knife to "cut" the bond between the dryfix and the breeze blocks. Once the sheet was off I was able to peel the dryfix off the plasterboard in one piece so that from a distance it looks like a strange pink mullioned window frame. The damage to the paper on the back of the plasterboard is minimal. No way would I have been able to get the board off if dot and dab had been used; the board would have broken, the paper would have been torn away from the board and a bolster and lump hammer would have been needed to get the remnants off the breeze block.

I shook the can well before use and it was in the airing cupboard for half a day so it was warm to the touch. Ambient temp in the room was perhaps 12 C; Everbuild recommends 2 to 25 C. The can is fresh, perhaps 10 months from its expiry date. The wall and the board were brushed down just before applying the dryfix. Interesting to note that Everbuild makes no mention of bond strength or suitability for subsequent tiling in their data sheet.

As an aside I rang their technical helpline a month or so back and they said its been tested in applications up to 40mm thick.

So further comments welcome, particularly as to what mechanical fasteners I should use should I wish to do so. I do suspect I'm answering my own question and that I should revert back to dot and dab...

 

[1john]

Ok, well in all fairness that isnt a very useful test, when is there going to be a paper stripping knife cutting through the product after install in real life, it is like cutting through D&D with a hand saw and saying it was quite easy.

A better test would be an impact test or a vibration test, things that will happen to the board. I have known boards to be loose from dabs in the past, this stuff however makes contact over a much larger surface area. The only fair test would be to install two boards as per the manufacturers instructions on the same background and try and remove.

If you can contact everbuild technical then you only need to enquire as to what weight the product will hold.