bowing floor Help, advice, information, answers and tips on all types of flooring from laminate and carpet to timber and vinyl

[thecrazy1]

hi all

I live in a 130yr old mid terrace victorian house the upstairs bedroom was used as storage and a slate pool table had been in room for a while this has resulted in the floor having a dip in the middle, both ends of the floorboards adjoining the side walls are level but as you get nearer the centre it drops.
i first looked at packing the joists but there are about 10 that need attention all joists are solid so would sistering new wood to the exising be the answer to get the floor level i only need to run the new wood about 3ft in from the window to straighten it.
i cant go the whole lenght of the room a) because there are horizontal dividers between each joist and b) i dont want to remove all the floorboards some have never been removed before and i am hoping to paint the boards and leave them uncovered.
my question is what size wood should i use to sister the joists it was suggested that i could get away with 2x1 to just bring the floor level

thanks all

[alexpowers]

Only my opinion but if joists exposed you should get as much wood to wood contact for the sake of £50 ,
If the floor has bowed then its weakend so stablizing is the key word,
Also Id bolt rather than screw.

hope this helps :)