https://stream.echo6.co/videos/watch/73593be3-12b7-4d33-a3b6-9291b9a9a8bb This Old House plumbing and heating expert Richard Trethewey shares tips for installing new radiant-heat tubing on top of an old subfloor when there's no access from below. SUBSCRIBE to This Old House: http://bit.ly/SubscribeThisOldHouse Cost: About $10-$15 per square foot, plus mechanical component costs Time: 2-4 days for an average-size room Skill level: Somewhat easy, but connecting the radiant tubing to the boiler must be done by a pro Shopping List for How to Retrofit Radiant Heat: radiant-heat panels used to hold PEX tubing in place in subfloor, 1 5/8-inch drywall screws for fastening down the radiant-heat panels, Tools for How to Retrofit Radiant Heat: drill, for boring holes and driving screws, rubber mallet, used to tap the PEX tubing into the grooves in the radiant-heat panels, Steps: Fasten the plywood-backed radiant-heat panels to the subfloor with 1⅝-in. screws., Stretch a continuous length of PEX tubing back and forth across the floor., Use a rubber mallet to tap the tubing into the grooves of the radiant-heat panels., Run the tubing ends down through the floor to the boiler., Mount the manifold to a wall near the boiler, then connect the tubing ends to the manifold., Run piping from the boiler to the manifold., Install finish flooring over the tubing., About Ask This Old House TV: Homeowners have a virtual truckload of questions for us on smaller projects, and we're ready to answer. Ask This Old House solves the steady stream of home improvement problems faced by our viewers—and we make house calls! Ask This Old House features some familiar faces from This Old House, including Kevin O'Connor, general contractor Tom Silva, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook. Looking for more step by step guidance on how to complete projects around the house? Join This Old House INSIDER to stream over 1,000 episodes commercial-free: https://bit.ly/2GPiYbH Plus, download our FREE app for full-episode streaming to your connected TV, phone or tablet: https://www.thisoldhouse.com/pages/streaming-app Follow This Old House and Ask This Old House: Facebook: http://bit.ly/ThisOldHouseFB Twitter: http://bit.ly/ThisOldHouseTwitter http://bit.ly/AskTOHTwitter Pinterest: http://bit.ly/ThisOldHousePinterest Instagram: http://bit.ly/ThisOldHouseIG http://bit.ly/AskTOHIG For more on This Old House and Ask This Old House, visit us at: http://bit.ly/ThisOldHouseWebsite How to Retrofit Radiant Heat | This Old House https://www.youtube.com/user/thisoldhouse/ Mon, 13 Apr 2026 20:41:24 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://stream.echo6.co https://stream.echo6.co/client/assets/images/icons/icon-512x512.png https://stream.echo6.co/videos/watch/73593be3-12b7-4d33-a3b6-9291b9a9a8bb All rights reserved, unless otherwise specified in the terms specified at https://stream.echo6.co/about and potential licenses granted by each content's rightholder.