Boarding loft, removing a binder. To cross batten, sister, or hang?

[Chris-1979]

Hopefully someone can offer some advice on this. I want to board the central area of my loft. 2.6m width by 6m length. Ceiling joists are 3x2 so on the weedy side. Supported by 2 5x2 binders running the 6m length which are supported on masonry. head height is at a premium so I don’t want to raise the floor height too much. There are walls below although the internal walls at 1st floor level don’t line up with that at ground level so presumably aren’t up to taking any huge support. The centre binder needs to go, but given that’s not supported on masonry and I’ll be adding some additional strength, I think that’s ok?

Options that I can see are

1. Sister the joists within the central 2.6m only, so between the supported binders. That’s where the additional weight will be, it’s across a couple of walls and should prevent deflection?

2. Cross batten. Should firm up the floor and spread load?

3. Use joist hangers to support new floor joists for the loft floor from the supported binders + support on internal walls. Would be independent (ish) of the ceiling joists, but too much load on the binders?

Any thoughts on this appreciated

 

[blup]

I would be wary of removing a binder on 6 metre long 3x2” joists, if I read the description correctly. The binders function is to restrain rather than support,

Blup

 

[gonch69]

Also binder is helping to support ceiling mid span so don't add more weight to them

 

[RandomGrinch]

An old post from @tony1851 :

Strengthening Loft floor

I am looking into having my loft converted for storage. I want the floor boarded, roof plasterboarded and loft ladder installed. The loft currently is full of a lot of boxes possibly 100kgs worth. I have had someone come round to quote for the work and they have advised me ''that...

www.diynot.com

But I've taken the advice as suggested (Thanks Tony!) and it's made a huge difference to the strength of my 3x2's
May be you could strengthen the joists between the binders in a similar way?

 

[cdbe]

5x2 binders at 6m span aren't supporting anything, you must be getting support from the internal walls below - they don't necessarily have to be directly above GF walls - could be built off double or triple joists etc.

 

[Chris-1979]

Thanks for those replies.

blup & gonch69 - Yes, figured the middle binder was there for a reason, but was thinking Options 1 & 2 would fulfuil the same purpose restraint wise?

cdbe - Thanks. Ok that's option 3 out of the question then. Still leaves a 3.6m span to the right which seems a lot given the joist dimensions.

RandomGrinch - That's a new idea on me. Good to hear it worked for you. Thinking that might be the way to go between the 2 supported binders along with noggins to provide restraint lost by the removal of the central binder. To my mind this would provide more strength and rigidity that cutting them in either side of the central binder.