how much can i trim off a joist ?


Postby tomerny1 » Thu Feb 02, 2012 7:23 pm

Hi there, i am currently doing my loft conversion and about to put the joists in. The span is under 4 metres outside wall to internal load bearing wall. But at the outside wall i will have to cut joists at an angle to fit them in. I'm using 8"x2" timbers. The ceiling joists are 3"x2". I will probably have to cut joists down to 3" at the end. Does anyone know if i can do this.? or if there is a way of strengthening them at the ends ? Any help would be appreciated.. thanks...Tom..
tomerny1
Rank: Labourer
Progress to next rank:
50%
Posts: 3
Joined: Thu Feb 02, 2012 6:55 pm

Sponsor

Simply Build It

Postby welsh brickie » Sun Feb 05, 2012 10:42 am

obviously you need to cut them but keep it as tight as possible to the angle of the roof,there is no other way.
welsh brickie
Rank: Project Manager
Posts: 2411
Joined: Sat Apr 12, 2008 7:54 am

Postby tomerny1 » Tue Feb 07, 2012 11:09 pm

thank you. was also thinking of using "restraint strap" to tie joist to rafter. thanks again...
tomerny1
Rank: Labourer
Progress to next rank:
50%
Posts: 3
Joined: Thu Feb 02, 2012 6:55 pm

Postby andy01 » Fri Mar 16, 2012 11:35 pm

you proposing to reduce the depth of the joist from 8" to 3". The shear is greatest at then ends and should be checked to ensure the timber does not fail. The structural engineer you are using to provided the required calcs to building control can check this out for you.
I would use JJIs or FJIs with the proprietry end supports for just this occassion, less calcs involved then
andy01
Rank: Ganger
Progress to next rank:
12%
Posts: 68
Joined: Sun Feb 07, 2010 7:18 pm

Display posts from previous
Sort by
Order by



  • DIY How to Project Guides

  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!



 


  • Related Topics