Hi Don,

I am sorry - that mistake was a result of a case of early morning Stanley rule dyslexia. I should of course stated 16".

The Bishop's Camera roof rafter spacing is also 16" as well and very conveniently this works out at 3 x 16 = 48 i.e. 4 ft spacing every 3rd rafter. That means that the nominal space between the rafters is now only 10". A skinny man (not me) can climb through the gap between the collars and into the space above between the scissor braces - just!

I think that I have managed to get it right this time - I hope!

Regards

Ken Hume