Installing hardwood floors

[Steve Jenkins]

We are going to replace carpet in our bedroom with 3/4” x 2-1/4”prefinished oak. I’m pretty sure the floor joists run the same direction I want the oak. Also pretty sure the current underlayment is 1-1/8” particle board with tongue and groove edges. I’ll know for sure when I rip up the carpet. Opinions on this? Thanks

[Jim Becker]

Ideally, you want the strips to run perpendicular to the joists. But you may be fine with the heavy underlayment you have with proper glue and a flooring nailer which puts them in at an angle.

[Steve Jenkins]

I’m hoping that is the case. Being solid oak flooring I plan to nail with a flooring nailer. You think I should also glue?

[Mark Bolton]

You think I should also glue?

No.

There can likely never be a guarantee running the flooring parallel with the joist but I'd imagine a straight edge tossed on the floor after the carpet would tell you if there is any oil canning in the subfloor. Your only adding the weight of the material but it would be much better if possible to run perpendicular.

[Richard Coers]

1 1/8" particle board underlayment? Never heard of it. I've converted to only using engineered locking floors now. It's just so damned easy! And since I will soon be 68, I don't need any flooring with a 30 year warranty!!!!

[Mark Bolton]

1 1/8" particle board underlayment? Never heard of it. I've converted to only using engineered locking floors now. It's just so damned easy! And since I will soon be 68, I don't need any flooring with a 30 year warranty!!!!

Even home crapo has it in certain locations. Also available in a stranded, osb-like, version Ive seen numerous times
https://www.homedepot.com/p/T-G-Sheathing-Plywood-Common-1-1-8-in-x-4-ft-x-8-ft-Actual-1-069-in-x-48-in-X-96-in-724092/202088752

[Peter Kelly]

If you’re planning solid wood and a nail-down, I’d pull the particleboard and nail into the plywood deck. Raising the floor another 3/4" might mean trimming door bottoms and flakeboard isn’t great at holding nails so potential squeaking.

Might want to consider floating engineered flooring as mentioned above otherwise.

[Mark Bolton]

If you’re planning solid wood and a nail-down, I’d pull the particleboard and nail into the plywood deck. Raising the floor another 3/4" might mean trimming door bottoms and flakeboard isn’t great at holding nails so potential squeaking.

Might want to consider floating engineered flooring as mentioned above otherwise.

He said he has 1 1/8" T&G sub carpet over. There is likely nothing below, 1 1/8" T&G adhered straight to the joists. Very common.

[Tom M King]

I have always nailed it into the joists.

[Ron Selzer]

No glue
perpendicular to floor joists
Good Luck
Ron

[Dan Friedrichs]

I had a similar question about a year ago and got some excellent feedback from many creekers, in this thread :
https://sawmillcreek.org/showthread.php?276829-Hardwood-flooring-over-particle-board-subfloor

[Jim Dwight]

I've put in about 800 ft2 of prefinished flooring, almost all hickory. I put it perpendicular to the floor joists when I could but I think some is parallel. My sub floors range from 5/8 plywood to 1 3/8 plywood (two layers, 5/8 and 3/4). The new area, the largest area, might be waferboard, I'm not sure. None is particle board. That would bother me but 1 1/8 is pretty thick. I'm not sure how well it will hold staples, which is what I recommend you use. Many flooring nailers will use either cleat nails or staples. I've also taken up flooring, installed by both types of fasteners, and staples hold far better. If your sub floor is truly particle board, I would try stapling it with a narrow crown staple and see if you can pull it. If it breaks before it comes out, you will be fine. If it comes out easily, you have an issue.

You probably know this but leave a little gap at the walls. Expect the flooring to not be straight. I sometimes drove a large screw driver into the subfloor to move a reluctant board where it belonged. But mainly this goes pretty fast. A helper to help you line up boards will greatly speed things up. They do not need to be strong, just strong enough to move one board. They need to give you boards with the desired color match and the right length to stagger the joints. If they can cut boards as needed they will be even more useful. The HF flooring nailer works fine and may end up being cheaper than renting a nailer.

[Steve Jenkins]

More info.
I pulled up some carpet and it’s not particle board. It’s 3/4 OSB with tongue and groove edges glued and nailed to the joists. There is nothing under the osb. Using the prefinished 3/4 to match the rest of the house. Laying parallel to joists is preferable for the way it will look but if we can’t we can’t. Thanks
I say osb but not sure if wafer board or flake board are different names for the same thing.

[Ron Selzer]

More info.
I pulled up some carpet and it’s not particle board. It’s 3/4 OSB with tongue and groove edges glued and nailed to the joists. There is nothing under the osb. Using the prefinished 3/4 to match the rest of the house. Laying parallel to joists is preferable for the way it will look but if we can’t we can’t. Thanks
I say osb but not sure if wafer board or flake board are different names for the same thing.

Kinda losing me here, are you saying the rest of the house has this floor already installed parallel to the joists?
I would make it match the existing flooring in the rest of the house for look. For strength perpendicular to joists.
It is a bedroom which is not a high traffic area.
Good luck
Ron

[Steve Jenkins]

The bedroom we’re working on is an addition and they ran the joists the same way as the rest of the house so I can match the direction which is perpendicular to the joists but since are using prefinished it won’t match exactly where new meets old in the doorway so thinking that running it a different direction will look better. We want to avoid the sanding staining,finishing process

[Jim Haberkorn]

Run it like the rest of the house. Any mismatch in finish will only be seen at the doorway, about 36 inches max. And only when the door is open

[Steve Jenkins]

Decision made. We are going to run it across the joists like the existing. Thanks for all the help and willingness to get more info from me.

[roger wiegand]

I've always put 15 lb felt under hardwood. Across the joists is preferred but running the flooring the "right" direction for the rooms is more important-- ie don't run it crossways in a long narrow space. Some people think it's important for all the flooring in a house to run the same direction, I don't. Changing directions (tastefully) actually helps to better define spaces.

Nails, no glue. You want the floor to be able to move evenly with the seasons (the felt paper helps with that). And have pity on the guy who someday may need to pull it up.

I do a picture frame border (with contrasting woods in a couple of widths) around my rooms when I DIY hardwood; it looks really nice, gives a high end feel to the project, and is only trivially more work to do.

[Mark Bolton]

Perpendicular

[Alex Zeller]

Is it just particle board or Advantech? Particle board isn't that strong but if it was built in the last 20 years it's most likely Advantech which is very strong. What's the floor joist spacing? If 16" on center it's most likely stiffer than plywood. I can't think of a contractor who uses plywood for a subfloor anymore.

[Eugene Dixon]

Make sure the subfloor is secure with additional fasteners before laying the hardwood. Sand/plane the high spots. LL has an underlayment (pad) that has been good for my hardwood floor installs and no smell like with tar paper.
Run hardwood parallel to the length of the room to increase the perceived size.
YMMV

[Wayne Cannon]

Sounds like two questions: subfloor and direction.

My floor joists change directing in the middle of the living room because they support a cantilevered deck. I put down 3/4" unfinished oak flooring over a layer of felt with no glue and 1/4" side gap for expansion using a Harbor Freight air nailer with no regard for joist direction and no problems.

I had very little problem with warpage, but used a large screwdriver driven into the subfloor to pull them snug, anyway. The nailer angle also drives boards snug when you hit it with the mallet. For traditional T&G, a special router bit for flooring was very helpful to easily re-groove cut ends and narrow pieces (it also reduced waste to almost zero, so I had a lot left over).

It was my first flooring job. I have been very happy with the results. I'll try a perimeter border next time, as I now know it's not a big deal and looks nice.

[Paul F Franklin]

HW flooring run perpendicular to the joist will add stiffness to the floor. If the current floor without flooring is stiff and not bouncy, then there should be no issue running it parallel. But check for flatness; sometimes with inadequate subfloor you will get "waves" or dips where the subfloor sags between joists. If you have a wavy subfloor, then you will have wavy flooring if you run it parallel to the joists.

[Bruce King]

We had the 3/4 prefinished oak in the living room, foyer, dining room and kitchen. We didn’t like the looks of it but the 20 yr old house we bought had sawn lumber floor joists with a multitude of dips and creaks so it was an easy decision. We picked out a more expensive engineered hardwood that is easy to lay if you don’t count angled doorways. We wanted to keep the same height so fixed all the dips with various pieces of cheap vinyl flooring squares. Screwed down all the squeaks and added 1/4 OSB everywhere. Used a pneumatic stapler every 8 inches. Put down the thickest underlayment to help on the height and for feel. We did the entire house except for two guest baths. This stuff works fine in a master bath. All new shoe molding and looks like a new house. Ended up with 400 Sf extra that we kept.