My new project - loft conversion. How to level the floor?

Caporegime
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So after a pretty tumultuous year with all the building work amongst various family bereavements we're now twiddling our thumbs because we've nothing to do. We had the structural work done to the loft but didn't convert it due to costs, and it's something I'm going to be doing over the course of the next year. With no time pressures or need for the space it should be pretty therapeutic!

First challenge though is to level the floor! How do I go about doing this? I can't pour any self leveling stuff because it's ceiling of course!
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The purlins sits proud of the joists unfortunately due to issues the builders had when putting the steels in:
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And the old joists are lower than the new ones as the new ones are modern day building reg/code/wossit, and the old ones were basically twigs so may well need reinforcing anyway.

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Over to you Ocuk!
 
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Could you just make those bits storage around the edge then just worry about the middle area which is level anyway?
 
Yeah thats the plan - building in sliding door storage all the way round the eaves in front of the purlins.

I think it would be a miracle if the old bit was entirely level though! I suppose I should have investigated that first :p.
 
So you have bits that are lower than other bits?

Can you just plywood the lower bits to raise their height to the height of the rest of the floor.
 
Aye it would have been sensible to check the levels first /facepalm. So the Purlins are all level so I can as you say plywood out to get things up to the level of that and then floor it. Might have a few tricky bits because some of the old joists aren't level but will be fun getting it sorted!
 
I had a loft conversion done last year. I'm not sure if you are planning on making it a habitable space but a new floor has to be created so no load is being placed on the existing joists. My conversion had enormous steel supports (can't remember the proper name!) craned in and slid in to position. You can just about make them out in the image below. They weighed a tonne or 2 each and had to be bolted in to position. The floor is then built on top of it.

VRydlPf.jpg
 
where are your steels?
is it massively off the level? you can lift all the floor and put fillets onto the joists to level it out but it will take a huge amount of mucking around, unless it's miles out I wouldn't bother with trying to get it dead level
 
They are under and running parallel to the purlins, a square frame basically to support both the roof and the weight of a floor with one across the middle as well.
What are you planning to use it for. Is it just storage or something else, ie a full blown room with proper stairs etc or what?
Master bedroom with bathroom. It'll have a staircase.
 
Personally I would use old fashioned floorboards.
Work across, filling under each with shims as needed to get them level.

Leave a few with the tongue cut of so you can easily access "sections" should you need to at a later date. You can position these carefully based on what you expect to put where.

Just running a plumb line across the loft in a few places now will tell you how far out you are.
Get it level and then work down until it hits the highest point. You will then understand the amount of deviation.
 
I normally level it before I do anything by just adding cut stripwood to the joists. Easy if youy have a table saw, not easy if you don't. You could attach packers I suppose as long as you use them say 1 foot apart, Just tack them to the joist.... but I never tried that becuase I do have a bench saw.
 
@rexehuk I think had a thread wherehe leveling out his floor with plenty of pictures. I'll wait for him to confirm it was him though before you start hunting through build logs :p
 
Either screw some strips to the old joists level with the new ones or bolt some new joists to them with coach bolts and serrated washers - that is what I did to mine

I’d put in some fancy loft ladders first before commencing any other work
 
@rexehuk I think had a thread wherehe leveling out his floor with plenty of pictures. I'll wait for him to confirm it was him though before you start hunting through build logs :p

Yup that was me. Bought a table saw and cut down 2x4 into custom strips to match the deviation in each joist.

Build log viewable on my profile
 
Yup that was me. Bought a table saw and cut down 2x4 into custom strips to match the deviation in each joist.

Build log viewable on my profile
Cheers I'll have a gander!
they don't look like floor joist in the first pictures, you'll need a properly supported floor before continuing
Yeah, they're not. Part of the job will be to replace the old joists.
 
I may be missing something, but can't you leave the existing joists in and lay new, deeper, joists (uniform depth) in between ?
 
It’s normally less work to lay new joists above the existing.

If you were to replace them then every upstairs ceiling would have to come down

Be careful, DIY loft conversions can make the building unsafe and effect ability to get a mortgage on it
 
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