Have spent last couple of days stripping wall paper from 3 rooms, so far I have been pleased with results ie good plaster and most previous paint taken off as well, just sugar soap left to do then sand and fill. Then late last night whilst stripping this wall we found this cannot work out what the hell it is. There were wardobes built onto this wall and it is an outside wall so initially I thought it was some sort of damp proofing but then we revealed the 2 white fingers.... I dread to try removing this, after sanding and washing what would be the best cover up paint for this as we want to finish these walls white.
That's chust rude, that is. Can't wait to find out what it is - 'cos I haven't a scooby. Definitely purposefully done, tho', so possible an attempt at fancy wall decorating? What does it feel like? Is it a higher level than the surrounding wall - is it an extra 'layer'? Anyhoo, if you have any concerns - and frankly, even if you don't - I think what I would do since this is an outside wall is cover it with 4mm WallRock to give a smooth, easy to paint finish, but mainly to add a very useful extra level of insulation to that wall. I don't think you'll regret it. If you can afford to lose an inchandaquarter from that wall, you could even fit Thermal Plasterboard which will really make that room much nicer in the warmth stakes. But, what that is - no idea...
DA means WallRock Thermal Liner, (4mm thickness) you will have to think about it though as it costs close to £100 per roll plus adhesive. Watch the video on Youtube.
(I love this forum 'cos you don't have to be fussy about what you right, 'cos there's lots of peeps to sort out the detail after you... ) There is a cheaper version too, I believe, that's only 3mm thick? Yep, it's not cheap stuff, but I think I know what I would do (and wish I had done to many walls in my current house when we moved in.)