Timber flooring - joist directions

[jlamplough]

Hi all,

I'm laying 18mm h/w flooring on yellowtongue. (Glue +n secret nail). How important is it to ensure that the floorboards are also 90 degrees to the joists? (In one part of the house the joists run one way and in another they run the other).

Cheers,
Jeremy.

[silentC]

I would say very. I wouldn't rely on nailing into particleboard alone, I'd have thought you'd want to nail into the joist as well. Besides that, it just wouldn't seem right to me to have the flooring parallel to the joist direction. It means only every 4th or 5th board would be over a joist.

I could be wrong and am happy to be set straight.

[glock40sw]

G'day.
The T&G must always run at 90° to the joists.
It doen't matter what is over the joists (Y/tongue or Ply).

However, if laying a new floor over an old T&G floor, it will run at 90° to the old floor and forget about the joists.

Hooroo.
Regards, Trevor
Grafton

[jlamplough]

Thanks all,

That is what I was pretty sure of. Just wanted to see if I could avoid the direction change. (Won't look too bad),

Cheers,
Jeremy.

[Eastie]

Ok - perhaps I'm missing something?
Particle board flooring is structural and designed not to move/sag given correct installation and joist spacings (450mm joist centres for yellow, 600mm for red, etc), and the load of the t&g floor would not over affect the stability of the particle board. Thus why can't you install it running either way, other than if you are aiming at nailing straight through the yellow tongue into the joists :confused:

[glock40sw]

other than if you are aiming at nailing straight through the yellow tongue into the joists :confused:
Exactly...

[Gumby]

My floor is 13mm hardwood over existing yellow tongue board. It matters not which way the joists go in this case. You run the floorboards in the direction which will look best inside. Mine were glued with just the odd brad nail pooped where it was a bit uyneven. The glue does the holding.

This is from the Boral site:

http://www.boral.com.au/Docs/TechSpecs/Timber/slimwood_installation.asp?AUD=&Nodes=IC:Timber,IA:Floorboards,IR:Slimwood,IN:Spotted%20Gum&site=Boral

[Dan_574]

the particle board is a structual floor in itself, F11 I think so what the others have said you can lay your floorboards any which way you like. In theory the nails are there only to hold the boards down until the glue goes off.

[Gaza]

Mixed school of thoughts in the industry.
U should be able to run the boards in any direction if it is glue fixed with polyuthrne adhesive. Others say the joists are the only way to go. If you are planing on nailing though to the joist you will need a 45mm staple for the secret nail gun. The Std is 38mm.
I have laid a lot of floors over PB and glued it down and there was no problem.
Make sure you give the floor a good sand to remove any "wax" like coating that prvents the glue from sticking. Also if the sheets are water damaged sand the bumps out.

[silentC]

If it was mine I'd be nailing into the joists. Remember the Opera House fiasco.....

[jlamplough]

Mixed school of thoughts in the industry.
Make sure you give the floor a good sand to remove any "wax" like coating that prvents the glue from sticking.
The floor has been level sanded however there is still some coating in places. Is a floorsander necessary or is it easy enough with a orbital sander.

Cheers,
Jeremy.

[Gaza]

We just use an old floor sander with a heavy grit paper, no need to get in pro for this job. U could use a belt or ROS but will take forever and dust. yuk

[Dan_574]

Im at a loss to how you guys would be able to find out exactly where the joist is to nail into precisly seeings though its covered in pb

[silentC]

Isn't the PB nailed to the joists? ;)

[journeyman Mick]

Im at a loss to how you guys would be able to find out exactly where the joist is to nail into precisly seeings though its covered in pb

Locate joists by nail or screw heads, snap a few chalk lines, away you go! ;)

Mick

[dnljames]

I apologise if I am doing this wrong. I just found your forum and after reading some of your Q&A thought you may be able to help me. I am laying a 19mm h/w floor over yellow tongue. I am happy to nail through to the joists or just to the yellow tongue. What sort of glue do you glue the h/w down with and if nailing to the yellow tongue only how far apart do you nail?

Thanks for the help.

[jlamplough]

I used Bostik ultrastick as recommended elsewhere on the forum. I nailed every 300 - 450 mm. Most of the time I tried to go into the joists.

I used a Bostik Applicator Gun for the glue which I was able to purchase through Bunnings special orders.