That's the stuff.
Try a pointed object in an area with the white, and see how easily it penetrates.
I've been told that I may have white rot on the timber in my loft > space, but
> the pictures I've seen on dry rot treatment websites dont really
> resemble what I have. There doesn't appear to be any decay of the
> wood, but there is a coating of what I can best describe as a white
> salt, more like the effervescence you sometimes get on brickwork
> rather than a fungus growth. Any ideas appreciated
>
> Steve