Choice of floorboards

[yartin]

Hi
I am replacing floorboards in a first floor room:
1. Can I use 20mmx220mm (finished) redwood softwood PAR, which is thicker and wider than what I have now (redwood18mmx119mm T&G)?
2. Are 2 screws fixings per joist sufficient?

 

[big-all]

yes 2 are fine take note off services as you go
screws normally 2.5 times the board thickness so 55-60mm
as an aside 119 txg will be around 111mm coverage as it includes the Tongue

 

[yartin]

The room in question is 2500 x 3000 , is there any harm using wider boards like 270mm or the 220mm is good enough?

 

[big-all]

you are all ready quite a bit into cup and split territory with 9" boards in general you are better with ex 6/7 or 8" as shrinkage will become a greater problem as you cant get boards tight enough to stop gaps and in general round here the cost per extra inch in width doubles between 8 and 9 inch
and i must admit i had read 5" not 9" first time and as said avoid above 7" because off excessive gaps and possible splits

 

[big-all]

another point to note
if its an old property then the new electric and plumbing installed perhaps 10- 30 years ago will be along a plank centre so any change should be planned thoroughly to avoid the problem off 2 edges in the cutout without sufficient support

 

[petebuiltit]

You can use what ever board width you like. Try to keep the thickness the same so it's level at the doorway to the next room. Depending on width two or three screws per board joist is fine. Make sure the fixings avoid any wires or plumbing. You can use tongue tight screws if you want to keep the screw heads hidden.

 

[foxhole]

Floorboards are usually nailed , what screws.

 

[petebuiltit]

I love screws. Nice and easy to remove later if needed.

 

[yartin]

I am going for the 20x220 mm finished and will be using "lost trite countersunk self drilling screws".

 

[petebuiltit]

I am going for the 20x220 mm finished and will be using "lost trite countersunk self drilling screws".

Sounds good. I used those to gue tite screws. Sounds like the same as your suggesting.

 

[big-all]

if you go for 9" be prepared for 2-3mm possibly bigger gaps that will appear regardless off how tight you fit them with a clamp

floor board clamp at DuckDuckGo

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[yartin]

What would help to stop developing gaps/shrinkage, would applying wood oil on sides and edges before fitting avoids the issue?

 

[petebuiltit]

I have no idea of the moisture content, but you could leave the boards in the room for a few days to acclimate them. Not sure how good that would be though.

 

[opps]

Floorboards are usually nailed , what screws.

I prefer countersunk screws. Makes it much easier to lift them. Additionally it pretty much eliminates the risk of creaking further down the line. Also less noisy when fitting them.

Horses for courses though I guess.

 

[ree]

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.