While cleaning my roof I noticed that the roof vents have deteriorated so much they need replacing. These are the vents above the toilet and the shower unit.
Before just going ahead and buy parts that look like it I thought I would put it to the experts first so I am aware of pitfalls, problems and dimensional problems.
Can I even get new vents?

Before just going ahead and buy parts that look like it I thought I would put it to the experts first so I am aware of pitfalls, problems and dimensional problems.
Can I even get new vents?