Reply: 1
From: Kristine .
Hi, Rixter
Not sure about the physical position of the dampness as you have described it, but ...
(i) assume the brick wall is an internal wall ie feature wall
(ii) no other area is affected
(iii) You have tried not using the shower for a couple of days
(iv) you have checked that the dampness could not be coming from anywhere else eg room condensation or damp rising from the foundations. Effleurescence of bricks is not uncommon, particularly if the damp proof course in the sub-floor area has broken down or is missing.
So get on your overalls and ...
a) Can you get underneath the house, and check for dampness along the bottom wall plate?
b) Can you check while the shower is running?
c) Can you determine if the pipes themselves are leaking inside the wall?
d) Condensation on the pipes and within the wall cavity can be a problem. there may be enough 'rubbish' eg old mortar, dirty wall ties etc to allow condensation to drip onto the wall instead of evaporating out of the cavity space
e) Check that wall ventilators are not blocked. In more modern houses, there are no wall ventilators and if rooms aren't 'aired' properly on a regular basis the wallboards can become damp quickly. Even though it's winter, open windows for a while each day.
So, if the damp proof course seems faulty, this will need to be inspected by a qualified builder / building inspector who will suggest various treatments.
If it definitely the shower, try your local newspaper for 'no more leaks' people who coat the tiles with an impermeable coating which takes about 24 hours to dry but is guaranteed
If it is the plumbing etc
In the meantime, brush or vacuum the salts off the bricks. Do not wash the salts off, this will simply dissolve it back into the bricks and it will reappear more quickly.
Best wishes for a speedy resolution
Kristine