Joists 100mm short of a picnic. Trying to maintain my sense of humour....

[PeterW]

Needs a mix of both I think. 

 

Block between the ends to bring it flush to the end of the hanger(one end) and then a full length piece with packers top and bottom. 

 

What thickness are the chords ..?? I’d be inclined to add a strong back regardless here as that end joint will move slightly. 

[Simplysimon]

5 hours ago, recoveringacademic said:

Weeeeeeeeeeelllll now: just heard back from the manufacturers. Cullens (the joist hanger chaps) have come up with this approved solution, have a look

 

 

What do you all think? What sort of timber should I use? Treated C24?

Ian

Ian, i'm struggling to see how this will work in relation to your pic. it seems to show another upright between blocking piece and upright or is it another upright after the original?

how long is the blocking piece to be or does it run the length of wallplate which would be difficult to position. i'm with @joe90 as i would have thought block should have been on end of top and bottom chord to stop deflection and at 75mm will only increase length by 25mm, is this sufficient at each end?

and how much bearing on the hanger?

[scottishjohn]

4 hours ago, JSHarris said:

Personally I prefer @joe90 's solution, with the "T" shaped infill, as structurally that it very much better, as is restrains the outwards load in the lower joist structural member.

 

When loaded, the upper member is in tension, so wants to pull away from the wall plate, and the lower member is in compression and wants to push in towards the wall plate.  Having end restraints positively stops the lower member from trying to cripple the lower edges of the hanger.

thats same as i described earlier in the day --but i suggested you make it up from plywood elemtns glued together making a gluelam tongue piece which will definatley be up to job --no need for engineering calcs

[scottishjohn]

18 minutes ago, Simplysimon said:

Ian, i'm struggling to see how this will work in relation to your pic. it seems to show another upright between blocking piece and upright or is it another upright after the original?

how long is the blocking piece to be or does it run the length of wallplate which would be difficult to position. i'm with @joe90 as i would have thought block should have been on end of top and bottom chord to stop deflection and at 75mm will only increase length by 25mm, is this sufficient at each end?

and how much bearing on the hanger?

I don,t like that the ends of the joist are short of going right to the back of the hangers ,must be liable, if over loaded floor to try to split hanger at outer edge cos the joist is only bearing on half of the hanger bottom plate,so that twice the loading if half the area

Edited November 28, 2018 by scottishjohn

[ProDave]

I don't get why you are even discussing this extension idea?

 

Have you admitted it was your error?

 

If the supplier is liable they should solve it. If they think they can solve it by extending them, they should be making and fitting the extension pieces and certifying that it is structurally sound.

[ToughButterCup]

13 hours ago, ProDave said:

[...]

Have you admitted it was your error?

[...]

 

Yes

See this post earlier in the thread ('... This isn't easy...')