Efflorescence on walls

Justamum

In our front room we have a problem which I (think) I have identified as efflorescence - it's a white 'fur' which wipes off easily.

The walls aren't damp where it appears.

The house is 1920s and stone. It's rendered and painted on the outside. The sand used for the mortar was just beach sand, so I'm assuming that's what is coming through on the wallpaper. Is there any way of stopping it or should I just wipe it away when it appears and put up with it?

brightontraveller

Salts in beach sand will cause problems so its not ideal some believe if the structure is going to be tidal use it ..

Basically cement bonds to the sand but not the salt thus weaker mix, reacts to form compounds which harm and corrode concrete, more irregular shape then river sand etc Weak, Efflorescence are the most common yes it was /is still used historically many buildings( Cornwall or coastal etc ) most weren’t going to be permanent now they are ?

Although you can make concrete with seawater and sea sand its not the best /easiest way to do so….
Water entering masonry dissolves inherent salts and problem starts? You can try acid based removers (acid pH is essentially required to dissolve the efflorescence) problem they wash off the process starts all over again?
Try to slow down the process, seal to the masonry, remove external render/ rake out motor, Cover over externally exposed areas ,minimising water ingression… Its not going to be easy if even at all possible to permanently remove completely without complete removal sea sand….[FONT=&quot]. If building is age /look appropriate some would just remove wall paper and keep painting over with white/lime wash... [/FONT]

Justamum

Thanks for your reply. It looks like it's something we'll have to live with - I'll just keep wiping down the wallpaper when it appears. By the sound of it, it's not going to be harmful. I'd have thought the render would keep water out?