The very thin mix of PVA I used consolidates the surface - it you scratch it it still dusts, get it wet and water doesn't bead up on it. Its not like the heavy duty water sealants applied to external walls which show water beading like it does on glass in the leaflets shoved through the door.dans said:I forgot that I'd asked this question, hence not thanking everyone for their reply! So thank you
I can see why you would not want to 'seal' an outside wall, but would breath ability be an issue on an inglenook? I don't want to plaster my fireplace, but would like to apply something to cut down the brick dust. PVA mix a real no-no? :?
Lime's suggestion of wall paper paste is a good one. Wallpaper pastes often contain fungicides which might not be compatible with an open fire (though any fumes would probably go up the chimney).
I had a quick google and you can make your own wheat based wallpaper paste if you're concerned.
I would expect either to work to cure the dusting. If you use the fire regularly I would also expect them both to need reapplying periodically - I'd guess PVA will melt (?) and wallpaper paste would dry out.
You could also leave the bottom couple of courses unpainted if you think you need some dissipation for rising moisture.
It's really up to you though!