How to strongly add a joist in a suspended floor.

[d000hg]

We have a suspended floor with main beams 6x4", actually doubled 6x2", 2m spans.

Joists are single 6x2" hung with truss clips, fine for flooring but we need to bolster between two beams to make it somewhat load bearing and I can't imagine truss clips are suitable for any kind of load.

My thinking is to put a strong joist between two beams... 6x2 or 6x4... But how to attach this so the connections are strong, what sort of fixings? I prefer an option that doesn't involve fashioning a joint as I'm no carpenter, but can screw or bolt things together!
Maybe big L brackets mounted in the angle between the beam and joint? Is there a suitable standard product on the market for this purpose?

 

[noseall]

Is there a suitable standard product on the market for this purpose?

What, like a joist hanger....

 

[d000hg]

What, like a joist hanger....

Are they rated for heavy loads then?

How do you hang a joist the same size as the beam, all the ones I've seen don't work that way?

 

[motorbiking]

something like this:
https://www.toolstation.com/multi-truss-hanger/p96448

You can always add noggins if you are worried about movement as this will help spread the load to the neighbour.

If that is too big, then use the mini-version and consider adding a ply sister and banding over the top for extra strength

 

[Notch7]

Are they rated for heavy loads then?

How do you hang a joist the same size as the beam, all the ones I've seen don't work that way?

As motorbiking has said -you need a heavy duty multi hanger designed for timber to timber connection.

Use the correct 3.75mm x 30mm twist nails -screwfix sell small packets.
You dont need to use bolts unless the loading is very high -just fully populate the nails holes.

 

[d000hg]

Great, seems easy enough.
Should I be able to find rated load on these things out of curiosity, if you were getting work signed off they'd have to factor that into the calculations?

 

[Notch7]

Great, seems easy enough.
Should I be able to find rated load on these things out of curiosity, if you were getting work signed off they'd have to factor that into the calculations?

The load rating will be on the manufacturers website, for example cullen multihanger or strongtie.
I doubt if you need it though.

 

[d000hg]

Looking at those from TS in detail I'm still a bit confused how they'd fit - I've confirmed I need to fit doubled 150x47 (6x2") hung off an existing 150mm beam.
All the wider ones seem to be more than 150mm:

Don't I ideally want a 94x152mm unit, or have I got mixed up here?

 

[cdbe]

There are loads of different sizes (but not stocked by Screwfix/TS). When I knock my internal wall out I'll need around 20 hangars, but they must have found my floor joists in the scrap heap because I have about 6 different width of joists, from about 50 up to 80, plus a couple of sistered to deal with. For yours, there's a 100x123 size (with a bit of ply packing) - you don't want it quite as tall as the joists as there's nothing for the top nails to bite into.