Uneven joists

[kiwipaul]

Whats the easiest way to plasterboard uneven joists? I probably should put new joists in but there is lots of wiring in the way. I read a post which mentioned 'shimming'. What does 'shimming' mean?

Cheers.

 

[masona]

Ceiling or stud wall?

 

[PowerTool]

And "shimming" is the use of shims - thin bits of appropriate material to fill gaps or (in this case) level something out.
i.e. - find the highest joist,use that to measure your level,and use shims to build the low points in your other joists up to this level.

 

[kiwipaul]

its a ceiling. most of the joists are fine, just where we have removed a partition wall the joists don't match up evenly.

 

[masona]

Put a straight edge across all the joists and make note of each gap thickness ( you will need to find the highest point and make it level from there), then pop down to the timber merchant from them to cut strip of timber from 2" thickness on their saw bench to the gap size to want (they sometime have the size you want without cutting it) and pin it underneath the joists. Use plasterboard screws when fixing plasterboards.

If you have a curve joists then something like a firring (wedge shape) on each end of the joist.