Prepping subfloor for hardwood floors

[branimal]

I had to cut out some sections of 100 year old pine plank subfloor to replace water damaged areas and also to run plumbing. The pine is 7/8+" thick.

I replaced the damaged areas with 3/4" ply.

Should I try to shim up the plywood to meet the pine subfloor prior to installing hardwood floors? Or will an extra layer of flooring underlayment on the plywood sections get me to flush?

Thanks

 

[wrenchguy]

i would padded it between the joist and p-wood with roofing starter ripped joist width. which way u gonna run the hardwood?

 

[ddawg16]

In addition to what wrench said, what kind of wood floor are you using? Nail down or click lock engineered? If the click lock stuff, you are going to be putting down a underlayment as spec'd by the manuf.....if nail down, if it's going to be parallel with the existing boards, expect issues.

 

[wrenchguy]

if nail down, if it's going to be parallel with the existing boards, expect issues.

u been there, seen it?

 

[James-W]

Many years ago I worked with a friend fixing up the kitchen floor in an older home he purchased. The kitchen floor was similar to the one you have, old boards on the floor and some areas were rotted.

We ended up removing all the old boards and putting down plywood. Once that was done he had someone come in and put down hardwood flooring. But that kitchen floor was rather small, about 12 feet by 16 feet so it wasn't all that difficult or costly to do.

How big is the room you are working on? If it isn't too big, it may be worthwhile to rip out the boards and install all plywood. If it is a large room, that's a different story.

 

[Skiff Builder]

If able, add a 1/2 or 5/8 underlayment over the whole floor.

Refasten any loose pine boards.
Knock down any cups or high spots w /sander.
Shim your patch area.
Than you can run new hardwood any direction.

Skiff Builder

 

[wrenchguy]

If able, add a 1/2 or 5/8 underlayment over the whole floor.

Refasten any loose pine boards.
Knock down any cups or high spots w /sander.
Shim your patch area.
Than you can run new hardwood any direction.

Skiff Builder

this, except, not putting underlayment down and running it parallel with the boards pictured u'll have gaps like the boards its fastened to.

 

[rburke65]

You'd be wise to shim the new plywood or replacing all the subfloor.

 

[jkuro]

Use 7/32" underlayment, available at Home Depot, to shim your floor. Your 3/4" ply plus the 7/32" underlayment should get you your 7/8+". Rip shim strips and glue and screw both underlayment and 3/4" plywood into place. Use tar paper or an equivalent between subfloor and new hardwood. Run new hardwood perpendicular to existing subfloor.