FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In
Ask the Experts

Flooring Over Plank Subfloor

Whether or not you need plywood underlayment under engineered wood flooring depends on the condition of the original subfloor.

Issue 286 - Oct/Nov 2019
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

We will be installing engineered wood flooring over an old tongue-and-groove plank subfloor. The subfloor is in good condition, but we are thinking of putting plywood over it before installing the flooring. Is 1⁄4-in.-thick plywood okay, or do we need something thicker? And should we use rosin paper between the plywood and subfloor?

—DAVID via FHB.com

Rudy Kelosky, owner of Wood Floor Designs, Inc., responds: Depending on the condition of the subfloor, you may not need the plywood at all. Solid-board subflooring should be 3⁄4-in. by 51⁄2-in. group 1 dense softwood such as Douglas fir or larch.

Check the current subfloor for flatness, protruding fasteners, and squeaks, and reattach any loose boards. If the board subfloor is in poor condition, use plywood as a clean, flat surface to glue down 1⁄2-in.-thick engineered flooring. If the subflooring is in good shape, nail it down without the plywood, assuming the engineered wood is of good quality and 1⁄2-in. thickness or more.

If the current subfloor has tongue-and-groove hardwood planks, check to see if it is attached directly to the joists or if it’s on top of another subfloor. If it is attached to the joists, you can use the 1⁄4-in. plywood to establish a flat surface and separate the two hardwood surfaces to avoid the expansion and contraction differences between the two hardwoods. If it’s on top of another subfloor, remove the tongue-and-groove hardwood to get down to the lowest subfloor level. Check for squeaks and flatness, and install plywood if needed.

As for the rosin paper, it may help with squeaks between the subfloors, but you are better off addressing the root cause, which is proper installation of subfloor and hardwood. Follow the manufacturer installation recommendations, and inspect the subfloor and fix the squeaks before installing the flooring. It is best to use #15 felt paper as a moisture barrier between the subfloor and hardwood if nailing down, or between the subfloors if gluing.

Drawings: John Hartman

From Fine Homebuilding #286

More about flooring installation

11 Wood-Flooring Problems and Their Solutions – For flawless wood floors, avoid these installation and finishing mistakes.

Save Time With a Prefinished Wood Floor – Factory-finished products mean less work on site, but they demand a more careful installation.

Install Wood Flooring Series: Laying Out Flooring – Making all calculations, adjustments, and layout marks before you lay the first board will get you professional results on your next flooring project.

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters
×

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

New Feature

Fine Homebuilding Forums

Ask questions, offer advice, and share your work

  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

More Ask the Experts

View All
  • Installing Prefinished Cabinet Molding
  • Tall Deck on a Sloped Lot
  • Hard-to-Use Electrical Outlets
  • HVAC for a Slab-on-Grade House
View All

Up Next

Video Shorts

Featured Story

Podcast Episode 684: Masonry Heaters, Whole-House Ventilation, and Porch Flooring

Listeners write in about fireplaces and ask questions about whole-house ventilation, traditional porch flooring, and gutter sealants.

Featured Video

How to Install Cable Rail Around Wood-Post Corners

Use these tips to keep cables tight and straight for a professional-looking deck-railing job.

Related Stories

  • FHB Podcast Segment: Designing and Building an Efficient Slab-On-Grade Home
  • A Modern Texture With Historical Roots
  • The Twister
  • Mastering Floor Design and Construction: Tips from Industry Experts

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

Video

View All Videos
  • FHB Podcast Segment: Designing and Building an Efficient Slab-On-Grade Home
  • FHB Podcast Segment: Sealing a Floor Cavity in a Slab-on-Grade House
  • Podcast 606: Foam Slabs, Gaps in Click Flooring, and Board and Batten Rainscreens
  • Podcast 587: Members-only Aftershow—Basement Flooring
View All

Floors and Coverings

View All Floors and Coverings Articles
  • A Modern Texture With Historical Roots
  • The Twister
  • Mastering Floor Design and Construction: Tips from Industry Experts
View All Floors and Coverings Articles

Fine Homebuilding Magazine

  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers
  • Issue 327 - November 2024
    • Repairing Damaged Walls and Ceilings
    • Plumbing Protection
    • Talking Shop

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 81%

Subscribe

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data