Uneven suspended floor

[Mrxman]

Hi there

We have sanded original victorian suspended wood floors on our ground floor but have been thinking about installing engineered floorboards on top.
They are sloping a tad from room to room though, particularly the corridor.

Would anyone be able to give me an idea of what's involved with straightening the floor? Is it big job?

Thanks

 

[Notch7]

I can’t see any easy solution for that, TBH.

I suppose in theory self level could be used - but I can’t see that working on top of floorboards, it would crack with the movement of the boards.

If I was doing it, I would remove the original floorboards, set out datum with a laser, then cut thin tapered pieces of wood to fit onto each joist. Then board with structural engineered boards 20mm / 22mm thick. They would need fixing down to each joist.

If you wanted a floating floor, then board the floor with plywood or chip flooring first then use a 12mm engineered clip system floor

 

[Mrxman]

I can’t see any easy solution for that, TBH.

I suppose in theory self level could be used - but I can’t see that working on top of floorboards, it would crack with the movement of the boards.

If I was doing it, I would remove the original floorboards, set out datum with a laser, then cut thin tapered pieces of wood to fit onto each joist. Then board with structural engineered boards 20mm / 22mm thick. They would need fixing down to each joist.

If you wanted a floating floor, then board the floor with plywood or chip flooring first then use a 12mm engineered clip system floor

Thanks. A floating floor might work but won't there still be some sloping even with plywood subfloor?

 

[Deleted member 174758]

I think what @Notch7 is saying is that you need to take out the slope, regardless by adding tapers on top of the joists. The only other effective way is to cover the boards with thin plywood then add a layer of SLC to level it all up.Either way, there is no fix that doesn't take a bit of "sweat equity"

 

[Notch7]

Thanks. A floating floor might work but won't there still be some sloping even with plywood subfloor?

Not if you level the joist tops first.

an alternative would be sister the joists with some 3 x 2 - screwed on firmly and set dead level to a laser or spirit level datum ….I didn’t suggest it because of the price of timber these days.

cutting thin slivers of tapered wood is not necessarily easy unless you have the gear to do it.

 

[tell80]

What is causing the floors to slope?
Are there gaps below any skirting?
Has anyone crawled the sub-area and examined conditions?
Were any flooring or structural issues raised on the last survey of the property?

 

[Mrxman]

What is causing the floors to slope?
Are there gaps below any skirting?
Has anyone crawled the sub-area and examined conditions?
Were any flooring or structural issues raised on the last survey of the property?

I've have examined conditions of sub area and put in new joists in corridor so they're all in good condition. I am gonna do some additional repairs in other areas. No stuctural issues has ever been flagged up. The slope in the corridor is actually only about 3-4 mm so I am thinking I may be able to raise the joist by sistering.

 

[Mrxman]

Not if you level the joist tops first.

an alternative would be sister the joists with some 3 x 2 - screwed on firmly and set dead level to a laser or spirit level datum ….I didn’t suggest it because of the price of timber these days.

cutting thin slivers of tapered wood is not necessarily easy unless you have the gear to do it.

Luckily I bought timber joists 2 years ago when they were cheaper so sister the joist might be the way to go or alternatively get someone to do it for me.

 

[tell80]

I still dont know what you think the cause(s) is or if there are any gaps below the skirtings?


Why didn't you raise the few mm's needed when you were previously under the corridor floor replacing joists?
By wedging appropriate thickness packing pieces under the joist seats you can still raise the floor.