Yes, I've Googled, etc. As many different opinions about SBR as there are plasterers out there, it seems.
I have to shutter-up the top edge of some brickwork, so I can get a horizontal layer of render on top, in turn so that becomes the base for a tiled windowsill. The shuttering edge of the cill will let me float/skim to exactly the right thickness, to get the finishing tiles to the right height allowing for tile cement. Trouble is that it's a repair, and I can't re-tile the whole wall, so stuff has to line up pretty well.
I've been advised (told!) I should use SBR for bonding and waterproofing. I've also been told it's stickier than a really sticky thing, whether it's used as a bonding pre-coat or in the render mix itself. Stiking to the brickwork=good. Sticking to the shuttering=not good.
So what can I use on my "shuttering" so that I can easily remove it afterwards? I'm wondering about putting wide PVC sticky tape over a redundant bit of 3x1 or something like that.
Overall render thickness on top will only be 1/2" or so, tops, but I will need a clean, squarish edge to the front, in order to get the brickwork below rendered to the right finished line, hence all the complicated mucking about.
It's doin' me 'ead in! Someone must have had this problem before, Shirley?
E.