Boiler Flue Access Hatch

[Josh2]

In my apartment the boiler flue runs along the top of the celing and has been boxed-in. It's about 4.5m in lengh from the boiler to the wall.

The previous owner has not done a very good job of it so I want to have it redone. They also did not build in any access hatches to inspect the flue.

I want to make sure everyting is legal and safe so do I need to have a couple of access hatches installed? I've seen that access hatches should be 300mm x 300mn. This would be bigger than the box-in. Is it an issue if the access hatch is smaller? Are there any other alternative solutions?

Any advice would be greatly appreciated
Thanks for your time.

 

[muggles]

You can reduce to 100×100 if you have an inspection hatch at every flue joint

 

[durhamplumber]

You can reduce to 100×100 if you have an inspection hatch at every flue joint

Good luck trying to find the joints accurately.Before you start with issues about is the void fire proof etc.