Hardwood floor boards flexing between joists

[matt94surf]

Hi all,

We have recently purchased a timber postwar house which was quite nicely renovated by the previous owners. The floors are polished/painted hardwood, and compared to timber floors of other post war homes I have seen our's appears to be on the better side of normal. ie. no gaps between boards nice timber gain etc. However in some areas of the house the floorboards tend to flex considerably between the joists when walking around. I am wondering wether they were over sanded and thus are now thinner and this is causing the flexing (looking at the edge up against skirting boards it appears the sander has really got stuck into them), or wether it is the particular species of timber used for the floorboards or wether it is a combination of over sanding and the species of timber?

Has anyone come across this before and if so are there any suggestions to reduce the flexing other than laying a new floor over the top of the existing floor.


Cheers,
Matt.

[namtrak]

Hi Matt,

How far apart are the joists?

If the floor joists are say 600 apart rather than 450, you may be able to nail joists on the inside of the existing joists, which could take up a bit of the slack. Between 70 and 140mm depending on how you do it.

Are you sure that the floor boards are sitting flush on the joists and likewise the joists sitting on the bearers and the bearers sitting flush on the stumps? Quite often some or all of these cases can occur which can create the bouncy feel. Not necessarily hard to sort out if you can get in and under...

Do you have access to underneath the floor?

If you have access, you could jiggle joists into place in between the existing joists - halving the distance between them.

Cheers
and best of luck

[barnsey]

Matt,

Namtraks come up with as good a solution as I could think of.

My only reservation is that is if as you suggest the previous owners took to the floors you may well have boards that could be less than 10mm thick. It could even be that a cowboy floor sander did it - maybe a phone call to the former owners could get you an answer.

Try using a marble to see if the floor is level and that will lead you to where to look under the house. If you can't get under and want to fix it properly, pulling up an edge board or two maybe the only solution.

You can usually pick up floor boards of a similar timber at a demolition yard or you might chose to replace it with a totally contrasting timber to create a feature.

I wouldn't try and go over the top if you can't fix it with the other solutions offered

FWIW

Jamie