Floorboards Vs Plywood

[Ooops]

I have finished removing 22mm floorboards and replaced with 18mm wbp plywood in order to tile the floor. My local Wickes and Build Center did not have 22mm ply. I added some noggins and screwed the ply every 25mm or so. The whole floor now seems more springy and less sturdy than it did with the floorboards. For example when I stand in the middle of the room and bounce up and down a little a bookshelf at the edge of the room wobbles a little. Any comments/suggestions as to what I should do?

correction: I screwed the ply every 250mm not every 25mm

 

[gcol]

...when I stand in the middle of the room and bounce up and down a little a bookshelf at the edge of the room wobbles a little. Any comments/suggestions as to what I should do?

Either go on a diet, or replace with 25mm ply. I always recommend using 25mm ply when replacing floorboards.
When you say it "wobbles a little" do you mean, rocks or just vibrates? It shouldn't really rock - vibration is usually fine. Get someone to have a close look at the floor when you bounce on it. Check for obvious signs of localised movement. If you have movement, you'd be advised to replace with 25mm. Just out of interest, what screws did you use?
Use a decent flexible adhesive too. Have a read of the sticky post near the top of the floor tiling forum.

 

[Ooops]

Thanks for the reply.
I should go on a diet you're right

I would say the bookshelf vibrates more than wobbles. I used a mixture of 2 inch and 2.5 inch screws. There are no signs of obvious movement and I think I'm going to lift it all up and add some more noggins.

thanks for the advice about replacing with 25 mm ply but I have not taken the skirting boards off or the door surrounds. 25mm would be too thick.

 

[joe-90]

18 mm is flooring grade so if there is more bounce than there was then the odds are that your joists need attention. If it's a ground floor you can probably brace a joist bearer on a few bricks underneath.

 

[Ooops]

Thanks joe-90. It is a ground floor but I'm not sure what a joist bearer is or how to install it?

 

[mattysupra]

18 mm is flooring grade so if there is more bounce than there was then the odds are that your joists need attention. If it's a ground floor you can probably brace a joist bearer on a few bricks underneath.

you can get 4mm floor grade plywood. The thickness you use is down to joist spacing. If taken up 22mm boards you should replace with the same or thicker.

 

[joe-90]

A joist bearer is a hefty length of wood that braces the other joists in the middle but in the opposite direction. It's the same principle as a purlin in a roof. This takes the bounce out of the floor by dividing the room in two.

 

[Moz]

the Floor needs strengthening ......
noggins ,25mm ply at most as said here ...


"A joist bearer is a hefty length of wood that braces the other joists in the middle but in the opposite direction. It's the same principle as a purlin in a roof. This takes the bounce out of the floor by dividing the room in two."

forget that ...if movement of joist like that its structure !!!!!!

never tile too that substrate as the building isnt right /susidence
an tiles crack after few months .. FACT !!





(where's jase
When you need EXPERT ADVICE when you need him,not joey lol )

 

[joe-90]

What planet are you on today eh Moz?

 

[Ooops]

Sorry to throw this one up again but...

I cannot afford to replace the 18mm ply with 25mm ply and it would be a real waste of the 18mm ply (I've got no other use for it). I am planning to lift the floor and add a whole load of noggins ie every 20cm between the joists. Do you guys think this is acceptable?

Apologies again to keep going on about this.