Choice of floorboards

[morqthana]

I thought those "lost tite" type screws were for driving at an angle through tongues so that they are hidden by the groove from the next board, just like lost nails are when using a flooring nailer?

So if you're not using T&G boards....

 

[yartin]

I thought those "lost tite" type screws were for driving at an angle through tongues so that they are hidden by the groove from the next board, just like lost nails are when using a flooring nailer?

So if you're not using T&G boards....

You can use them instead of nails and countersunk screws.

 

[yartin]

OP,
The type of flooring, and how its fixed, will depend on how you intend to finish the floor. Why are you replacing the old flooring?
Its typical IME to use, say, 150mm T&G not PAR boards for floors - esp with your concerns ref shrinkage.

The floor boards are the the finish in this room. I have replaced nearly quarter of the damaged T&G boards with PARs years ago, no shrinkage issue. I now decided to change the whole flooring with PARs for a better look overall; no concern of shrinkage until was mentioned here. They are bare boards; once purchased this week will be left in the room for a couple of weeks to acclimate, also planning to apply Osmo Polyx oil on all sides before fitting and then a final coat.

 

[big-all]

The floor boards are the the finish in this room. I have replaced nearly quarter of the damaged T&G boards with PARs years ago, no shrinkage issue. I now decided to change the whole flooring with PARs for a better look overall; no concern of shrinkage until was mentioned here. They are bare boards; once purchased this week will be left in the room for a couple of weeks to acclimate, also planning to apply Osmo Polyx oil on all sides before fitting and then a final coat.

what size where your last lot off boards ???
you may be fine and any shrinkage may be within exceptable levels as a 1-1.5mm gap can fill with wax but a larger say 2-3mm gap may not

 

[yartin]

what size where your last lot off boards ???
you may be fine and any shrinkage may be within exceptable levels as a 1-1.5mm gap can fill with wax but a larger say 2-3mm gap may not

They were 120x18mm

 

[big-all]

its your choice but would think cupping splits and shrinkage may be a problem
you will probably need 3 fixings but i dont know as its not a normal size i would use for flooring

 

[yartin]

its your choice but would think cupping splits and shrinkage may be a problem
you will probably need 3 fixings but i dont know as its not a normal size i would use for flooring

20mm wood planks are stronger than mdf, osb or chipboard sheets. They do wide planks 200mm engineered wood which must be working; can't see why 20mm solid wood won't work.

 

[big-all]

20mm wood planks are stronger than mdf, osb or chipboard sheets. They do wide planks 200mm engineered wood which must be working; can't see why 20mm solid wood won't work.

most 220mm will tend to be through and through cut timber and include the tree heart or close too and this is the area most likely to cup and if it cant cup the grain can open up

engineered wood is far more stable as its more than one layer and evens out the stresses

 

[big-all]

i have used 100s off metres off 9"in furniture making for tops and in the end i would either rip it down the middle or glue sub 7" planks together alternate cup up and cup down as call back for split tops exceed the theoretical time saved from fewer glue joints and assembly time

 

[Deluks]

I'm in agreement with BA, wider boards are asking for trouble, and might look out of place.

 

[yartin]

I will try see what happens, they are cheap...

 

[yartin]

How about 7x1 , finished 169x20mm?

 

[big-all]

How about 7x1 , finished 169x20mm?

yes a good compromise as any visible cupping or shrinking will be around half that off 9" as effects are multiplied with small size gains
for example iff you take a cupped 9" board and the middle is raised by say 7mm iff you rip it in half the raise will be perhaps 1 to 1.5mm for each half assuming you dont flip the other half for gluing purposes so 7" will be perhaps 3-4mm raise for the same cupping so far far less chance off movement or shrinkage

 

[yartin]

Why don't OSBs, MDFs or chipboards sheets suffer from cupping? They're weaker and bigger than 220mm planks with similar thicknesses.

 

[big-all]

because they dont have a grain to cup along as the fibres are now short and in every direction at once cancelling each other out
think off a handful off drinking straws

remember each ring is a different years growth and pressures can build up and cause movement around the radius off the grain
cupping is just the wood relaxing to the no stress position in a similar way to rolling thin sheet material and then letting it go