Wall cavity opens into bathroom inside plumbing box

[Robert Laws]

In the 1960s house that I have just bought there is a cavity wall on the ground floor but much of the upper floor has a timber frame wall with plywood/hung tiles on the outside and insulation (polystyrene) and plasterboard inside. the cavity in the lower floor wall is open and exposed between th eGF ceilign and the FF floorboards.

In the bathroom, the flooring does not even cover the cavity. It is concealed only by a 'box' containing the plumbing. At present all that prevents moisture from the bathroom from condensing in there is the presence of the box which is a very lightweight plywood affair.

Surely this cannot be right. Should the top of the cavity be covered in some way?

thanks,

Robert

[pablomartin]

You would need to be carefull about bridging the cavity , perhaps some insulation in the box or a auto humidity extractor ?

pablo

[Robert Laws]

Thanks, I won't change anything unless I am sure, but a dish of calcium Chloride would do no harm I guess.

R