chris_d
Established Member
Dear members,
My overly cautious structural engineer has 'helpfully' specified 225 x 63 mm C24 stress graded timber joists for the upper storey floor of my extension. At one end the joists will sit in masonry hangers and at the other they will be built into a steel beam (actually a universal column for convenience).
I wish to achieve a flush ceiling line to make fixing the plaster board easier. Hence, I intend to notch the bottom of the joists where they sit in the masonry hangers and the steel beam so that the underside of the joists finish slightly proud of the underside of the hangers and beam.
I also need to place concrete padstones to bear the steel beam; the finished depth of the timber joists (as delivered) and the block course datum upon which the hangers bear dictate the proposed vertical position of the beam and padstones. Due to labour, weather and storage constraints, the padstones and steel beam must be in their final position before the timber joists are delivered to site. I therefore require the finished depth of the joists to calculate where to place the padstones ASAP.
I don't exactly purchase timber joists every day but I'm aware that C24 stress graded and 63mm wide joists are not commonly used. The manufacturer of the masonry hangers purposely reduces the depth of the hanger by 10mm from nominal to 'allow for regularised timber and notching for a flush ceiling line'. I've heard of the finishing terms CLS and regularised in the context of joists but I'm not aware of what impact that has on their finished dimensions.
Please could a kind soul educate me with regards to the final delivered depth of nominal, regularised and CLS timber joists?
Thanks,
Chris
My overly cautious structural engineer has 'helpfully' specified 225 x 63 mm C24 stress graded timber joists for the upper storey floor of my extension. At one end the joists will sit in masonry hangers and at the other they will be built into a steel beam (actually a universal column for convenience).
I wish to achieve a flush ceiling line to make fixing the plaster board easier. Hence, I intend to notch the bottom of the joists where they sit in the masonry hangers and the steel beam so that the underside of the joists finish slightly proud of the underside of the hangers and beam.
I also need to place concrete padstones to bear the steel beam; the finished depth of the timber joists (as delivered) and the block course datum upon which the hangers bear dictate the proposed vertical position of the beam and padstones. Due to labour, weather and storage constraints, the padstones and steel beam must be in their final position before the timber joists are delivered to site. I therefore require the finished depth of the joists to calculate where to place the padstones ASAP.
I don't exactly purchase timber joists every day but I'm aware that C24 stress graded and 63mm wide joists are not commonly used. The manufacturer of the masonry hangers purposely reduces the depth of the hanger by 10mm from nominal to 'allow for regularised timber and notching for a flush ceiling line'. I've heard of the finishing terms CLS and regularised in the context of joists but I'm not aware of what impact that has on their finished dimensions.
Please could a kind soul educate me with regards to the final delivered depth of nominal, regularised and CLS timber joists?
Thanks,
Chris