Odd Loft Joists

[Boatfixer]

I was in the attic of an old Edwardian house today. This was just a small apex over the attic rooms but it had something I have never seen before. The ceiling joists of the attic rooms were curved on the top edge - they were maybe 2" tall at each end and 6" in the middle with a nice curve along the length. You could see the saw marks on the top face where they had been shaped but I can't see why anyone would go to such effort in a space where they would never be seen and where a straight bit of wood would be fine. Now I haven't been in many attic spaces so maybe this is more common than I would have thought but why would this have been done?

 

[carlb40]

Added strength to counter act sagging over time would be my guess. Just like we do now when fitting timber joists etc, we put the crown ( bow) to the top. So when weight is added it levels out.

 

[blackrodd]

I was told that in many instances, the reason for shaped timbers was to use up the odd shapes as much as was practical.
In my sitting room the ceiling joists are ash, and are the same shape cart shafts, matching shape for 12' and then opposite shape for the next 12', an interesting conversation piece.
Not forgetting the huge amount of effort used to cut timber by hand in the saw pit, in days of old when most materials of every day life was valued very highly! Regards Rodders

 

[Drudgeon]

I have seen many edwardian and Victorian joists, and I've seen many that vary in thickness, often toothpick sized at the ends and a few inches thick in the middle, but as has already been said, these would have been recycled timber from possibly a boat, cart, or basically anywhere that no longer required them, but I've never seen any that look like they've been specifically shaped for where they are.

 

[Boatfixer]

That was the conclusion I came to thinking about it overnight. Someone somewhere has a nice barrel shaped ceiling and these were the offcuts which were too useful to just burn. We all have piles of bits that will come in handy someday....

 

[RogerS]

Yup...they were past masters at recycling. Our house, part of which is about 300 years old, features curved oak timbers that came from a boat!

And you can see in many of the oak beams that there is no rhyme nor reason for the empty mortices other than that the timbers were recycled from elsewhere.

Like here for instance...