uneven floorboards

[jstrats]

Hello peeps just a quick question:

Looked at job today, bathroom floor 5m, floorboards, solid but big dip in centre.

Can i fix Durabase to them and SLC over the top?

Cheers, Jamie.

 

[Ajax123]

Depends why they have sagged ?

 

[jstrats]

Not sure, am presuming joists uneven? Old Victorian house

 

[Del W]

Before doing anything,Id want to pull up the floor & see what the problem is.

 

[Ajax123]

If they are just uneven that is fine but if they have sagged as a result of wet rot softening them or wood worm etc etc.... All possibilities in old houses then it may be that adding the extra weight of a tiled floor will cause problems. I would just chek it out first. I would also everley the floor boards with 6mm hardibacker or similar before tiling. A it's a bathroom I might also be tempted to tank

 

[jstrats]

Am trying to keep height down to a minimum, If it is just uneven joists can I not just install the Durabase? If not I just want to know the reasons, it's not a wet room either so I don't see the need for tanking.

 

[Ajax123]

It's not about keeping the height down its about installing a tiled floor on a timber floor which has "sagged" that sagging could be due to many things but they include, creep, over loading and rot. If these are issues your floor could collapse. It would be unwise and in the worst case scenario downright dangerous to tile this floor without knowin why it has sagged. Just my opinion ..... Perhaps you will get a different answer from others.

 

[jstrats]

If it is the joists that are uneven what is the best solution?

....without taking them up and re-levelling.

 

[bugs183]

He's right Js.
If you take on this floor you inherit any problems that may come with it. Woods a bad enough substrate to fix on, let alone with any sagging or age etc.
Old floors are often out of level from one side to the other, but sagging is showing that something isn't right with the floor.
Get it properly checked out for doing anything, a customer can soon point the finger if you don't.

 

[jwatson]

tile backer board

 

[Stef]

If its only the joists that are uneven then you could go straight over it with Mapei Renovation screed as long as the floor is deflection free.

As said above an old house with sagging joists could be anything.

I would personally check that floor before i even attempted to prep it.

 

[Ajax123]

The Victorians (at least from aout 1870 onwards) were relatively good builders. They used copious quantities of machined timber for floors, wall plates, roofs, stud walls etc etc. they rarely built floors with dips in them. Ok there were probably cowboys even then. The implication is that the floor has sagged and is not just "uneven joists". You need to lift a cople of oards to see. It is ridiculous to offer solutions to a problem unless you know what the prolem is that you are trying to evolve. Are you just going to fish for the answer that you want in order to o ahead with the job or do you want to do it properly...... Is the client putting you under pressure??

 

[jstrats]

I will get the customer to lift the boards and check it out, thanks for the info.

 

[bugs183]

It's worth it mate, things like this need to be investigated, so everyone has piece of mind.
See what's going on underneath ideally after any work is done the whole floor should be replaced with 18mm ply wood.

 

[Ajax123]

I will get the customer to lift the boards and check it out, thanks for the info.

Good call.