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Transition for 5/8 Partical Board to 3/4 Plywood for hardwood

johndrew's picture

I have a den 22x24 and have 5/8 partical board on it with carpet. Now I want to put down hardwood over the partical board. I have one doorway in the foryer which is 3/4 plywood. Can I sand down the plywood to make a transition to the 5/8 partical board. The subfloor under both is 1/2 plywood.

I am 70 years old and don't want to have to tear up the partical board if I can prevent it.

Your thoughts would greatly be appreciated.

John (post #207336, reply #1 of 6)

I'm 63.

I'd remove the particle board-it isn't suitable to hold anykind of flooring nail or staple.  It at the most will keep your nails from connecting to anything worthwhile-joists or even the 1/2" ply subfloor.

If it were to get wet, it could blow up like a poisonous toad, perhaps pushing your new oak floor right along with it.

If you remove it, beat down all the staples or underlay nails, you'd then have to add the 3/4 ply or osb to it to bring it up to the other floor ht.


you say foyer?  How big is that?  I would suppose an exterior doorway in that foyer?  If not that big, yank that ply up, gain the 3/4" and now have a place to put a substantial foot wiping throw rug.



Leave the pb, take a chance and put down the oak over it.   Perhaps change direction and put the oak down down in the foyer, over the 3/4 ply.   Make an oak transition at that opening that gently ramps up the qtr inch from one room to the foyer.


I'll try to get a hold of a professional long time flooring installer to come here and give his opinion.

Best of luck.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Like Calvin said or was (post #207336, reply #2 of 6)

Like Calvin said or was thinking.

Many get the terminlogy mixed up with subfloor material, but I'm thinking it may be real (particle board) PB because it was a cheap method to bring the carpet height up to meet with existing hardwood. Nah, foget that..doesn't maske sense. There isn't existing hardwood.

Yea, depends on what the PB is. Most of the genuine stuff cannot hold fasteners properly...causing squeaks and so forth. If it's a good OSB or similar, you're okay, as long as it's in good condition. I answered a near identical question not long ago on this, forget where. Tapering back from the high area is the most appealing way to do it. That way there is no need for a transition as the floor  flows evenly.


Common materials are #30 and #15 roofing paper placed under the hardwood, but don't overdo the #15 because it compresses too easily; once again creating a potential squeak problem.

Particle board was real (post #207336, reply #3 of 6)

Particle board was real popular underlayment in the 70s. I am not sure if that changed or if they still like it in some places. We had a supplier in Maryland that had a bunch of cabinet PB with the picture of wood on it that made an interesting sub floor.


Naturally I thought of (post #207336, reply #4 of 6)

Naturally I thought of placing the hardwood over the partical board until I read comments above and know how PB swells once wet. I have three outside doors on the South side of the house and rain is a problem under the doors. I am now putting in new ones to prevent the water from entering under the doors.

What would you recommend in front of the doors? Tile or just hardwood? Everyone says it will look better if it is all hardwood?

How should I install the exteror doors threshold to prevent problems later?  I have 1/2 inch plywood on the 2x8's, then there will be 3/4 plywood C/D and then the 3/4 Bruce hardwood.

 How high should the door be over the hardwood?

The roofing paper, should that be just below the hardwood or between the 1/2 inch and the new 3/4 inch plywood?  If I use 6 mil plastic on the ground  to prevent moisture, will I still need the "tar Paper"? Will it prevent squeaks?

Any advantages in using glue, staples or spured nails to put down the hardwood?

How much width clearance from the walls for the hardwood? The room is 20x24?

I would not use a wood floor (post #207336, reply #5 of 6)

I would not use a wood floor anywhere that water is a problem.


John (post #207336, reply #6 of 6)

How high door over floor?

If you plan to have a throw run to wipe your feet on-set the door high enough to clear whatever rug you get.  That will be provide there's enough clearance below the header.  There's not much leeway between the rough openings on new prehung entry doors.  Either ThermaTru or Masonite is a bit shorter than the other-call to find out which.

Patio doors, same story sort of.  Some are meant to replace old aluminum style-these would be shorter.  Call.

It's common practice to use paper between subfloor and hardwood.  Rosin paper would be fine.

For the install of the hardwood, I use staples in an air actuated floor nailer.   They hold well.   I have used a cleat nailer and they hold well also.   Back in the beginning of time, there was no air flooring nailer (or least we knew nothing about it was the mallet flooring nailer-now, one arm is longer than the other-I blame that on the footage nailed down using it.

Both drive the boards tight to each other-some claim the manual style is the only way-they are wrong.

We also installed many feet of flooring hand driving, not the best method tho you got real adept with a nail set.

Pick your poison-all will require back work later.

Here's a  (could not get the link to copy, see below)  to FHB articles/messages on the proper/improper methods of door unit installs.  Most of the companies now have diagrams and recommendations.  You'd be smart to spend a tad more on the offer of of a composite backed threshold and composite jamb savers (a non wood bottom section of side jambs.)

The sill pan (mentioned in the link) is to keep water that might have entered from getting into the interior finishes and framing (and directing it outside).  This shouldn't keep you from doing a complete weather proof install which should keep the weather out in the first place.  It is a last line of defense.

John, in the "Search the Forums" box up above, type in Sill Pans For Doors.  That should provide you with some information to get you started.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.