Loft conversion issue: Short term solution with long term benefit.

[Dan watts]

Hi all.

Im currently doing a load of work on the house and decided the loft would be a good place to store some unused materials and some tools. This is not going to be anything like a loft conversion. I just want a few boards up there for storage, which is easy enough. Im planning on hanging some 2x6 joists between some hefty binders and then boarding. However, i am considering a full on loft conversion over the next few years or so. Basically, if possible, i want to make sure anything i spend time and effort on now will not need to be undone in a few years if we decide to go for the conversion.

So, what can i do now that could contribute to a future conversion project, or at least would not need to be undone? Would i be better off taking a bit more time and installing new joists alongside the existing ones, that could eventually become proper loft space floor joists?

 

[Notch7]

loft conversions often need steels -so any boarding you do would most likely need to be stripped out for access

 

[frutbunn]

At this stage I would install a floor suitable for habitable purposes but this may involve steelwork depending on spans and load bearing internal walls.

 

[cdbe]

All I would suggest (if its a fairly conventional arrangement, ie two rooms on the first floor separated by a spine wall which would carry the inner ends of the new joists with the outer ends either on the outer walls or on steels set back from the outer walls) is to check some joist span tables and use suitably sized joists - it would be a shame to drag 6x2's up there when you'd need 8x2's. As suggested, it's unlikely you could permanently fix them for a future conversation but at least they'd be up there. In the meantime, hanging from binders would gain you nothing, other than adding the weight of the joists to the existing ceiling joists - do you mean purlins perhaps?

 

[Dan watts]

Good idea about checking joist size.

...In the meantime, hanging from binders would gain you nothing, other than adding the weight of the joists to the existing ceiling joists - do you mean purlins perhaps?

Surely by hanging from binders I’m transferring the load to the walls the binder is bearing on? Thry are bedded in party wall one side and rest on load bearing wall other side. I will probably put some hangers in from the purlins too.

 

[cdbe]

Surely by hanging from binders I’m transferring the load to the walls the binder is bearing on? Thry are bedded in party wall one side and rest on load bearing wall other side.

You are, (although some binders are only there to spread the load across the joists and don't even sit on the walls) but the existing ceiling joists are doing that already, and (assuming the joists are securely fixed to the binders) unless you're worried about them being overloaded across the (usually short) span from wall to binder you're not gaining anything.

Also, if they only span from spine wall to binder they're going to be too short for a loft conversion anyway? Full length joists cantilevered over the spine wall might be better and could be repositioned if you convert and won't interfere with your loft insulation as much:

 

[Dan watts]

I see what you mean. The reason I didn’t want to just build on ceiling joist was that they are only 3x2 holding lath and plaster ceiling, so really want to reduce deflection. Also, need space for insulation so thought on top of binder made more sense.

Good idea about longer joists across centre. How would you suggest I fix them if I want to recycle later?

I also thought about just doing it “properly”, running some appropriately sized joists from external wall to spine wall (4ish metres) alongside existing joists. That is presuming I’m allowed to do a design like this (I have seen it done done). If It’s possible to do mine like this when I do it properly, I could do some of it now and leave in place?

 

[cdbe]

Full size joists spanning across is probably your best option but it really depends whether you can get in at the eaves to sit them on the wall plate - I guess this is why most people just stop short and hang them off the steels, also the shorter span may allow smaller joists and gain a tiny bit more headroom.
Obviously though, the steels (you'll probably still need them to carry dormers/dwarf walls if not the floor) can go above the joists - I did this on mine because the stairs came up the side under a steel and I needed the headroom.

In another house I built a platform like the one I drew, I had a lot of heavy stuff to store
and also didn't want to load my poor 3x2's either, (they already had nearly 50mm of deflection mid span!) I screwed the outer ends of the joists to the ceiling hangers and added a few more - I did wonder if it might sway a bit but it was very rigid.

Have said all the above, if you do eventually have a proper conversion, you probably won't save much time or money with anything you do now, for example you might need to chop a few out for the stairs, or if you have an older house with high ceilings that need replacing anyway, you may want to drop the joists into the bedrooms to gain extra headroom etc. There's lots of old terraced houses near me with 3m bedroom ceilings, they often drop the loft floor 600mm down into the bedrooms and have a really big loft room just with veluxes.

 

[Dan watts]

Thanks for the advice. Think I’m going to just go with the purlin hanger idea for now.
Dan

 

[catlad]

If you shove a length of 4x2" down to the eaves then you can forget about resting things on the binder and rest your new floor joist on that, that will be stronger due to its location and if you chamfer the ends of the new joists to suite the pitch then you could also screw them to the rafter tails.

 

[Dan watts]

Yeah I’ve seen that suggested before. You mean just wedge the 4x2 as far in to the eaves as it will go? Then screw into ceiling joists? What’s the best method for getting around the 7x2 binder at mid span? Notch it out and attach it to new joists?