I'm starting to plan out the building regs on my new extension. I have two rooms that have 5250mm clear spans, and I'm already struggling for head height so don't want an excessive floor (joist) depth.
I'm almost outside of the standard span tables, but might just scrape a 72x220 at 400cc (which are good for 5362mm if less than .50 kN/m2) That would be 32 joists in total : £500.
Initially I thought I'd put a steel half way across the span with a timber bolted in to the webs to get the floor depth below 170mm, but then I thought I'd get a quote from one of the leading engineered joist suppliers to save myself all the bolting/fixing/faffing time. I was expecting it to be a bit more, but fell off my chair at £2000.
Is that the going rate, or should I keep plugging away for quotes from elsewhere? My mistake might have been that I specified metal webs rather than the OSB webbed ones, on the basis that I could also run a soil pipe through if required. I could probably adjust the design to avoid that if it would make a big difference.
I'm almost outside of the standard span tables, but might just scrape a 72x220 at 400cc (which are good for 5362mm if less than .50 kN/m2) That would be 32 joists in total : £500.
Initially I thought I'd put a steel half way across the span with a timber bolted in to the webs to get the floor depth below 170mm, but then I thought I'd get a quote from one of the leading engineered joist suppliers to save myself all the bolting/fixing/faffing time. I was expecting it to be a bit more, but fell off my chair at £2000.
Is that the going rate, or should I keep plugging away for quotes from elsewhere? My mistake might have been that I specified metal webs rather than the OSB webbed ones, on the basis that I could also run a soil pipe through if required. I could probably adjust the design to avoid that if it would make a big difference.