bof wrote:

In message , The Natural
Philosopher writes

Grunff wrote:

Dave Liquorice wrote:

I guess most comes up from the ground, but what about walls made of
that nice cornish granite?

The reason suspended floors with a 'sump' arrangement work is
because radon is very heavy, and will collect at the lowest point -
even if it is coming from the walls.


Ah. I hadn't thought that through. It has to be heavy, being
radioactive...


Not necessarily, Tritium isn't.


Tritium is not IIRC radioactive...