Weird white colouring on bricks

[jimbob1]

Recently had a building built in my garden. For a few months there was no gutters so alot of water went onto to the brcisk that wasnt protected. As you can see the bottom 3 rows above the engineering bricks are white. Those 3 bricks were very muddy at one point, i hosed it down a lot too. Thinking it was salt as it has started to dry out i put a bit of white vinegar mix with water onto it, it makes it look better but then goes back to this. Its cold in England at moment, maybe the summer will sort this out? Any advice at all please?

[Temp]

Think it probably is efflorescence (salt). I believe washing can make it worse, it removes the salt on the surface but the water penetrates the bricks and mortar dissolving more.

 

I'd just leave it alone or dry brush it off. It should eventually weather out but can take a few years. 

 

https://www.cement.org/docs/default-source/fc_mat-app_pdfs/masonry/is239-pca-efflorescence.pdf