Strengthening The Joists To Make Floor Slats Run The Same Way Throughout The House


I’m perfectly OK with installing the new subfloor w/ good 3/4″ ply, in addition to bolstering the strength of the joists (they change direction midway through the house) so the floor slats can run in the same direction throughout the home. But, should I ask the installer to just remove the entire floor and subfloor, or just the floor/staples and have us remove the subfloor? Anyway, your advise on this would be greatly appreciated. We’re actually thinking of moving very soon, so I want to get this resolved quickly, but also properly for the sake of the homeowners that come after us.

Thanks in advance.



Dear Doug

It sounds like you are making fast progress at least with installer. It would be nice if he removed the “old” floor and disposed of it. A good physical lesson he will not soon forget. Be sure to take pics and samples of the cracked boards as he does this. Whatever you can get out of him to pay for the destroyed floor would also be great.

But installers are just that: “installers”. They rarely know a thing about carpentry. And while it may seem simple replacing the subfloor is not a easy or simple job. In platform framing you cannot remove all the subfloor to the walls. It will need to be cut back to the nearest joist next to the wall. Load bearing and even partition walls need support on both sides. A ledge of at least 3/4″ plywood (1″ LVL is ideal) can be glued (urethane construction) and nailed to the side of the joist to support the edge of the new subfloor. Use this glue (it’s cheap insurance against squeaks) on all the joist tops as you nail (3″ spiral spikes or 2 1/2″ Spax screws) the new 3/4″ CDX plywood (spruce or better yet doug fir).

Have a good carpenter do this or do it yourself, to get it right the first time. Hire a new flooring installer, that uses flooring nails and not those infernal staples. And no pneumatic finishing nails for the last 3 rows either. I know that this sounds all too fussy, but it’s simply the way we all used to do wood floors, and I still do. Use prefinished floor, like Mirage or Lauzon, if you must get your life back to normal as quickly as possible.

An unfinished floor would be ideal. I hate to say it but depending on your area, there may be a dearth of good floor sanders. And I wouldn’t want you to go through another nightmare with a poor sanding and finishing job. Especially if you are going to sell the house. Whether prefinished or sand-on-site, a nice looking hardwood floor will add value to your house.

In most cases you will get your money back at least for the hardwood cost compared to a similar house that is simply carpeted. Be sure to brag about your new subfloor when the house goes up for sale. You will be a real Saint to the next owner if you do all this good work, that’s not even seen. If everybody was so diligent, wouldn’t this be a nice world to live in ? A contribution to the bank of human kindness, allows for unlimited withdrawals.

Oh, and like I mentioned before, the carpenter can add some 2 by 6 blocking on the “wrong way” joists to act like “joistlets”. Be sure that these are glued and nailed at about 16″ to 20″ intervals.