When I moved into my home last year the big water tank anf the little water tank which I think is called the header tank both had black plastic insulation tied around the sides bit it had fallen in the tanks.
Whoever had done work up there had left it in a mess and htere was some straw from a birdnest in the tank too.
I took out as much rubbish as I could and them made 2 plywood covers which I undercoated and glossed and fitted them over the 2 tanks.
It has been a few months since I did that, today I looked up there and the bottom of the glossed wood had condensation on and had a small amout of black mould on it which I assume could drip into the tanks.
Is this dangerous in any way?
I do not drink tap water but I do use it when brushing my teeth.
buy a proper plastic lid from screw fix. you are always going to get atleast some condesation from there. The small tank is central heating F&E tank so if its this one (which is the more likely to have condesation) I wouldnt worry too much.
The insulation is to prevent the water from freezing and bursting pipes in the winter, so replace it dont discard it.
It was made with bowed sides, that is the design of the Osmaflow tank.
I telephoned the company that supplied it, they were very helpful but they stopped supplying these back in the 1980's so I wont be able to get a lid for that one.
The lid I made is made from MDF and sawn batten, undercoated and glossed twice.It fits very well but condensation forms on the underside of the lid and this is where black mould is starting to form.