RSJ I-beam section to replace wooden joist

[knighty]

I think everyone is a bit off the mark here, he needs more ideas/input not critique of work done

re enforcing the joins like that isn't a permanent fix

if there's no room to get a beam in, and no where to drop a post down to, plus don't want to lose head room

then I think the best way forward is to run another 2x6 along side the roof joists

keep it as long as possible, have the center of it line up with the join

bolt it at each end and the middle

you'll need a spacer in one end of course, an offcut of 2x6 will be fine
(because the joint is stepped)

 

[addjunkie]

Anotheroptin. Stead f cut wood is to use an engineered wooden joist laminated type thing, I joist or the other ones cant think of the name, but they have squiggly metal in them, and you get much greater spans than cut timber.

 

[mangocrazy]

Hmmm - it strikes me that people see what they want to see and then criticize what they assume is the case, rather than what is actually the case. The wood isn't dried out and splitting, it's in good shape. The bolts are fastened from both sides, through both joists. Beam section is 150 x 50, bolts are M10 x 100, which means that the bolts fasten through all of one beam and 42mm of the other (and 8mm of plate). The bolts follow a line on each side, it is true, but the bolts on one side are offset horizontally and vertically from those on the other side (I believe I mentioned this before). All bolts were greased copiously before being fastened.

As for gaz1's sentence: A bent plate over both sides of the joists wood have been far better also using some of the joist as a strength point with bolts going through the beam and also the join onto the other beam - as far as I can see that's exactly what I've done.

Totally disagree that 4 bolts would have been sufficient.

 

[mangocrazy]

Anotheroptin. Stead f cut wood is to use an engineered wooden joist laminated type thing, I joist or the other ones cant think of the name, but they have squiggly metal in them, and you get much greater spans than cut timber.

That sounds interesting. Any idea what they're called?

 

[gaz1]

not if you used a z plate bolted to both sets of beams on there own and then 4 bolts been required for the cross over part of the beams would be than sufficient

total amount of bolts used 10 for the whole join

oh take a look for beams that collapsed due to aparty being held at there property was fine when they did it but the extra weight made it fail

 

[Burdekin]

I was just trying to be helpful, he's happy with it so fine. But I would definitely check the span, 150 X 50 for a 4.5m roof joist doesn't comply to my span tables .Hence my original suggestion of doubling the joist.

 

[mangocrazy]

not if you used a z plate bolted to both sets of beams on there own and then 4 bolts been required for the cross over part of the beams would be than sufficient

total amount of bolts used 10 for the whole join

Not familiar with a z plate. I'll google it.

oh take a look for beams that collapsed due to aparty being held at there property was fine when they did it but the extra weight made it fail

They held a party on the roof?

 

[gaz1]

you wnt find it on that reference

in more specific terms following your beam then coming over the other beam going past the joint say 1 1/2 foot in either direction after the ends of each beam

bolted through the single beam then bolted through both joints then bolted through the other single beam

the span covers both the single beams and also the joints

 

[gaz1]

https://www.bbc.co.uk/news/uk-england-manchester-27713888

https://www.telegraph.co.uk/news/13...-ends-in-the-basement-as-floor-collapses.html

and todays floor collapse on video
https://metro.co.uk/video/floor-collapses-party-clemson-university-clubhouse-1786958/

 

[mangocrazy]

I won't be holding a party on the roof. Promise.

 

[addjunkie]

Id be looking at these options, but if you google engineered timber. Youll find out more. They have much greater spans than normal timber

 

[mangocrazy]

Certainly seems worth checking out - thanks. Just need to find something of the right size and a way to incorporate it into the current structure.

 

[Hitch]

I had an engineer draw up a splice in some joints in case I couldn't get them in. 8x2 joists, 600mm overlap minimum, 4 x m12 bolts, with double sided timber connectors between the timbers, then single sided timber connectors on the outside, with 80x80 plate washers.

 

[mangocrazy]

I had an engineer draw up a splice in some joints in case I couldn't get them in. 8x2 joists, 600mm overlap minimum, 4 x m12 bolts, with double sided timber connectors between the timbers, then single sided timber connectors on the outside, with 80x80 plate washers.

I wish I'd known about those when we first did the roof, that would have sorted the job out for certain. Still, it gives me options to add another supporting beam, perhaps between the two problematic ones.

 

[gaz1]

you have forgotten this post

https://www.mig-welding.co.uk/forum/threads/new-lean-to.73677/

 

[eddie49]

Apart from bolts, studding, coach screws, timber connectors, square washers, and steel plates, does wood adhesive have any role in the retrospective sistering of timber joists?

 

[mangocrazy]

you have forgotten this post

https://www.mig-welding.co.uk/forum/threads/new-lean-to.73677/

You can't forget something you've never seen before.