It's not. You see it often, granted, but it’s not 'normal'.
By laying brick only in dry conditions. That includes artificial too, i.e covered, wrapping scaffolding, heaters, etc - rather than just waiting for dry sunny days which programme will rarely allow.
If those first salts don't get drawn out at the time of laying, they won't reoccur later.
That's btw from years of personal empirical efforts at it, fwiw. Tone can be misread, and I'm not trying to sound arsey here, I am responding to what I take as a genuine question, with what I know or think I know.
You do also get 'efflorescence free' brick. Most often glazed or semi glazed, and usually imported from Spain or made from spanish clays. But i've seen it get efflorescence too, and they then argue whether it is from the brick or the mortar. Forgetting that, it is fine being efflorescence free in Spain, where they lay it in compleyely different weather, and just bringing it here might not be enough.
They laid the brick on this one completely exposed, trough October to February months. Partly because there was no need for scaffolding, fair enough. But that then brings with it that risk. As others point out, it will eventually wear off though.
