Hi All,

I am building a brick bbq with a chimney on top. I looked at the building regs to determine what cross sectional area the chimney should have. Although this wouldnt be covered by it, it should give a good idea. The bbq is brick on 3 sides with an opening of just under 2 m2 which is bigger than their recommended 15% rule and they say to consult an expert.

Any idea what size I should use and why the 15% rule doesn't work for this size?

Also I was thinking of keeping the back flush with the back wall and corble the sides and front in to make the desired size. Do you see any issue with this?

Final question, is there any rule about how high except above the near bushes.

Thanks in advance.

Lee.