Hello , this is my first post on here and I am after some help. I am going to be knocking a wall down to make my dining room larger. The wall i want to take down will give me around another meter on the room. There are joist running across the wall ,the first set run from my stairs wall to the wall i want to remove ,the second set run from the wall i want to remove to my end wall. So both sets of joists sit in the wall i want to remove , the first joists are around 3m long , the second set around 1m long ,the joists are 7 x 2. The overall span will be around 4m long. My thoughts were to run 9 x 2 C24 joists along side the original joists and use joist hangers at either end ,and to bolt the 9 x 2 to the 7 x 2. The reason for the 9 x 2 is because i dropped my kitchen ceiling and the extra 2" would bring the overall ceiling level. Do you think this would be strong enough .
You need to get a structural engineer in to do some calculations. You can't use joist hangars and bolt the joists together.
Bozo, is all this happening on the ground floor? I only ask because you mention 7x2 joists, that suggests that they're chamber joists. I would take chippie's advice.
Thanks for your replies ,the joists are to the first floor ,the house is around 70 years old. If i added larger joists , the 2 x 9s graded c24 to cover the 4m span ,could i remove the 7 x 2s (Change 1 at a time ) or would this not be strong enough , so maybe go for 3 x 9s . My wifes cousin is an architect but getting hold of him is a nightmare..
I'm not suprised he's avoiding you, architects design things to look pretty, s/e's work out loading. You have made a large investment in your house, would you sooner pay a s/e £200 or whatever you would be charged to calculate what beams you need and to have this backed up by his insurance or ask on a forum and risk your house falling down. Get a builder in Bozo!
You could trust someone with £200 who owns a book. Or haringey.gov.uk have a handy page of domestic timber floors pdf This shows your options to meet building controls (without which selling later can be a nightmare). If I'd checked these myself first I would not have been fobbed off with 7x2s, and then had to have it ripped out and replaced with 7x3 after. Advice is if you are near a limit overspec as the cost difference in timber is minimal.
You could work out what should be done from the council charts, size of joists, seating & fixing on supporting walls, then submit it to Building Controls and spend your money wisely by having it certified. Though take care as modern timber is 'regularised' into metric & quite different to old english, so new 9x3 is not the same as old 9x3. So whether replacing or using together you need to be allow for the difference in size.
you find BC may ask u for S/E report on his/her calc to ensure your build confirm to the build regulations.
Forums
Facebook
Twitter
You Tube
Instagram
Shop