Lifting floor joists

[Jase1976]

HI all,

I have an old extension with a floor sloping approx 1" over the span of the room.

I'm aware I can sister the joists or pack them out top and bottom to level out the floor, but once I've taken out the floor and the ceiling below (removed pipework, etc), ideally, I'd like to level out the joists by packing underneath them so I don't lose any ceiling height (and because it'd probably be easier.

So assuming the joists are all sound and everything seems okay, what's the best way to physically lift them?

As in what's the best way to create space above the joist and what's the best material to pack underneath?

Many thanks for any/all help!

 

[noseall]

Stitch drill a hole above the joist and chisel out the material. Knock it up with a hammer, or it may just push up if the timber has had time to shrink. You can 'encourage' it with an acrow prop if it proves stubborn.
Use hard dense flat material for packing, i.e. roof tile, slate, solid engineering brick, quarry floor tile etc.

 

[^woody^]

Surely some 3x2 nailed to the side of the joist is a lot easier, quicker and less messy?

And if the dip is even, furrings on the top?

I can't understand what you mean by not wanting to lose ceiling height.

 

[Jase1976]

Thanks Noseall & Woody,

Woody, by lose ceiling height, I meant from the kitchen below. I want to level the ceiling of the kitchen and the floor of the bathroom which are the same joists.

My preference for lifting the joists is that I don't lose any space from either room. Assuming it is an inch (though it may be slightly more), then I'd lose an inch in the kitchen bringing everything down to the lowest point - and then an inch in the bathroom furring everything out to the highest point.

May not seem a great deal, but they are quite low ceilings in both to begin with.

Noseall - I never thought of that, it makes perfect sense.

Thanks guys.!

 

[roganty]

@Jase1976
You would be raising the joists at the lower end by an inch, so would gain an inch in the downstairs room!

And when you sister joists, it is an extra joist attached to the side, not the top or the bottom!

And what's an inch in the grand scheme of things anyway!!