Hi all
We are currently in the process of an extension build and are trying to choose the best sized domestic floor joists - By best, I am meaning that we need the joists to be as low profile as possible so as not to steal head height in the upstairs room which has a sloping ceiling.
Our exact "block to block" measurement is 3980mm, and we have purchased 45mmx 195mm C16 timber - however, I am looking at the C24 trada tables, and, based on the minimum over coverage of 90mm onto the blocks, we would have a span of 3960mm which is right on the limit of 75mm x 145mm C24 timber -
Some questions
Is the span taken from the outside or inside of the block (or is it just the length of unsupported joist) -
Is being on the limit a problem?
This is based on 400mm centres, and 0.25 dead load - Is a 0.25 deadload quite standard, or unlikely to be achieved (based on 1 x double bed above and 2 adults)
Any help welcomed
Many thanks
Gaz
We are currently in the process of an extension build and are trying to choose the best sized domestic floor joists - By best, I am meaning that we need the joists to be as low profile as possible so as not to steal head height in the upstairs room which has a sloping ceiling.
Our exact "block to block" measurement is 3980mm, and we have purchased 45mmx 195mm C16 timber - however, I am looking at the C24 trada tables, and, based on the minimum over coverage of 90mm onto the blocks, we would have a span of 3960mm which is right on the limit of 75mm x 145mm C24 timber -
Some questions
Is the span taken from the outside or inside of the block (or is it just the length of unsupported joist) -
Is being on the limit a problem?
This is based on 400mm centres, and 0.25 dead load - Is a 0.25 deadload quite standard, or unlikely to be achieved (based on 1 x double bed above and 2 adults)
Any help welcomed
Many thanks
Gaz