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

Discussion Forum

Discussion Forum

Engineered Hardwood and conductivity over radiant heat

BHT | Posted in General Discussion on April 23, 2011 04:17am

We’re planning replacing the current carpet & Pergo floor finishes in the first floor of our house with engineered hardwood.  This floor has staple-up (with heavy aluminum plates) radiant heat under the 3/4″ plywood subfloor (and over a crawl space).

There seem to be three choices for installing the engineered hardwood:  stapling/nailing it to the subfloor, “floating”, or glued down.

We’ve installed staple-down engineered hardwood in a prior house, and it worked well.  But, we didn’t have to deal with tubes full of water under the subfloor.  I assume that any nails/staples would (or might!) go through the subfloor and endanger the pex tubing.

Floating floors tend to be installed over some sort of cushioning material to avoid noise, but that will add insulation in a spot where we specifically don’t want it (between the radiant heat system and the room).  I also worry that the floor won’t have the “solid” feel that one expects from a wood floor.

Gluing down the floor should give it a more solid feel, and might help with heat conduction, but I’m concerned that the glue will prohibit the flooring from expanding and contracting with temperature changes.

So…how does one balance the pros and cons of the various methods?  What’s the recommended way to install engineered hardwood over a staple-up radiant system?  Does the answer vary depnding on the brand of flooring?  We’re willing to spend a bit more on higher quality flooring if it will make a difference in the finished product.

 

. 

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

Replies

  1. davidmeiland | Apr 24, 2011 07:05am | #1

    The answer is...

    Does the answer vary depnding on the brand of flooring?

    ...yes. Install it as specified by the manufacturer. 

    If you do a floating floor, the padding is a non-issue. It's very thin and has almost no R-value. Make sure it is approved for use over heated floors.

  2. Tim | Apr 25, 2011 05:22pm | #2

    Several comments

    Staple-up radiant floor heat is the least prefered (and least efficient or effective) way to use hot water and a large flat surface for comfort heating. If during this remodel, you have the option (and the know-how, time and money) to put the tubes above the plywood, I would recommentd doing so. Depending on the design of your boiler, being able to lower the supply temperature may greatly improve the efficiency (a condensing boilker is most efficient if the return water temperatures are below 120 deg), it also may cause extra difficulty (for a non-condensing boiler, i.e. cast iron, the lower required temperature may require a mixing valve and piping changes to prevent the unit from condensing on a regular basis).

    All that said, do not put staples or nails in the subfloor. Floating the floor is the prefered method. The "pad" is a small fraction of the insulation of say carpet. Also small compared to 3/4" of plywood. As recommended, check with the specific manufacturer for their recommendations.

  3. [email protected] | Apr 25, 2011 07:06pm | #3

    I wouldn't hesitate to staple it down.

    You aren't at risk of pentrating 3/4 inch subfloor stapling down 1/2 inch flooring with a 1-inch staple.  I have had them come back around on me from deflecting off the plys in the plywood, but haven't ssen them come through the bottom.   

    Figure the height to the top of the staple from the bottom of the subfloor as 3/4-inch, plus 3/16-inch, for 15/16. 

    Now figure penetration of the 1-inch staple at the 45-degree drive angle.  The cosine of 45-degrees is 0.707.  So, 16/16 multiplied by 0.707 equals 11.3/16.  Use 12/16 for the depth of penetration. 

    Then subtract the 12/16 from 15/16, for 3/16. 

    So, shooting the 1-inch 18 or 20-guage staples designed for engineered flooring installation, out of a dedicated engineered hardwood flooring stapler, you will be at least 3/16-inch away from the bottom surface of the subfloor. 

    Your call, on your place.  But, I wouldn't hesitate to staple down and engineered floor in your situation.  Particularly if the heating system you have is the one where the tubing slips into a track in the aluminum.  I think the aluminum is thick enough to deflect the staple at an angle.  Particularly in the thckened section, that holds the tubing. 

    PS  Check on ebay and Craigs list for a good used stapler.  I bought mine off ebay for around $100 dollars with shipping, and it shipped with almost 10,000 staples that the previous owner hadn't used in his install.

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

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

Up Next

Video Shorts

Featured Story

A Practical Perfect Wall

Getting the details right for a wall assembly with the control layers to the exterior and lots of drying potential.

Featured Video

A Modern California Home Wrapped in Rockwool Insulation for Energy Efficiency and Fire Resistance

The designer and builder of the 2018 Fine Homebuilding House detail why they chose mineral-wool batts and high-density boards for all of their insulation needs.

Related Stories

  • Midcentury Home for a Modern Family
  • The New Old Colonial
  • Modern and Minimal in the Woods
  • Bryce Hollingsworth, Dry-Stone Waller

Highlights

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

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

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

Fine Homebuilding Magazine

  • Issue 333 - August/September 2025
    • A Practical Perfect Wall
    • Landscape Lighting Essentials
    • Repairing a Modern Window Sash
  • Issue 332 - July 2025
    • Custom Built-ins With Job-Site Tools
    • Fight House Fires Through Design
    • Making the Move to Multifamily
  • 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

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 70%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

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