Yep them 200 or 225 timbers now acting as 100
low pitch extension roof
- Thread starter dfk778
- Start date
Does it matter considering the small span and requiring thicker timber to match the steels thickness / insert insulation?
Seems a bit odd they didn't birds mouth any of them. The roof was built by roofers and passed by building control.
Not quite. It is crap but 100mm rafters wouldn't work. Max bending moment is at the centre (more or less) of the span and that's where the 200mm depth is working hardest. 100mm rafters in the same situation would deflect too much. The main issue with those seat cuts is shear force (which is highest at the supports) and the potential for splitting.