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

Redwood Hot Tub Plans

| Posted in General Discussion on December 23, 1998 12:32pm

*
I need help with plans on building a wood hot tub. Does anyone
know where I can access plans ?

I especially would like the formula for determining the angle for the slats of the tub.

Thanks in advance,

Tom

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

Replies

  1. Steve_G | Dec 22, 1998 09:52am | #1

    *
    Tom--try this URL-- http://www.island.net/~butler/
    These folks have a bunch of plans, at least two of them for hot tubs. I have ordered reprints of magazine articles on several of their projects, and they seem very well thought out and executed.
    They use plywood and expoxy instead of redwood, but you could probably adapt the plans to redwood. They seem to be founded in shipbuilding techniques, so it should hold up well in this application.

  2. Tom_Pace | Dec 23, 1998 12:32pm | #2

    *
    I need help with plans on building a wood hot tub. Does anyone
    know where I can access plans ?

    I especially would like the formula for determining the angle for the slats of the tub.

    Thanks in advance,

    Tom

  3. Guest_ | Dec 23, 1998 12:32pm | #3

    *
    Tom: I've built a couple of hot tubs for myself over the years - both fixed and portable (I've got a 120-pound outfit that's gone on camping and snow camping trips). I'm a strong proponent of the taller, smaller diameter redwood-style tubs as opposed to the low profile, reclined seats jacuzzi ones. I find it more comfortable, easier to carry on a converstion with someone when you can look at them (instead of the sky), and easier to give a massage in. But I've never built out of redwood. Rather, I used fiberglass or plastic because it was cheaper, quicker, far less maintenance, and much more energy efficient. Energy efficient because you can insulate the outside of a plastic, fiberglass or epoxy-coated plywood tub but not a coopered redwood tub. The redwood has to breath. So your only insulation is the 1.5 inches of wet wood.

    Look at http://www.island.net/~butler/ but you can do better and avoid the corners. Use 1/8 marine plywood wrapped in a circle, and coated inside with epoxy resin (System Three is good). Use fiberglass tape on the seams and back the seam with another bit of plywood. At this point you've got a very floppy cylinder. Place it on an oversized circular plywood bottom and epoxy in place, reinforcing the bottom seam with fiberglass tape. Then build a stud wall around the outside, 16 inches on center and insulate with fiberglass batting. Wrap in 1/8-1/4 plywood (or T-111 and you're done) and side with shakes or vertical siding. Like building a little, circular house.

    It will still seem a little floppy until you fill it with (2000 pounds of) water. That will essentially nail it to the ground.

    Cheapest heat to operate is a natural gas hot water heater ($119 at Home Depot) and if you can locate it below the tub, it will thermosiphon with the need for a pump. Setting the thermostat of the hot water heater will control the rate of thermosiphon and maintain a steady (+/- 1 F) temperature but will need seasonal adjustment.

    Cheapest heat to install is the element out of an electric hot water heater ($8). Epoxy in a 1-inch female pipe thread fitting and screw in the element. I like to use 240-volt elements at 120 volts. You get 1/4 the power (1000 watts instead of 4000) but the element doesn't get as hot and you can use a normal circuit. (Or plug it into 240 when you are in a hurry). Spiffy, precision thermostat in the 100-105F range aren't cheap ($100-150). I either modify a $20 digital thermometer with alarm to trip a power relay or just put the 1000-watt element on a lamp timer (those things to convince the burgulars that you are still home). Just get a high wattage one and adjust it seasonally for as many hours of operation as needed (e.g. 2 hours/day summer, 9 hours/day winter).

    Epoxy-coated plywood is versatile stuff. I trust my 39 pound sea kayak in the ocean off Alaska and it's a single 1/8" thickness of mahogany plywood encapsulated in 6 oz fibeglass cloth and epoxy resin ($260 of materials).

    A 6-foot diameter tub holds 17 backpackers (max), but no clothes, and there was very little water left when they all got out. My next hot tub will be as described above, but elliptical, 3' x 5' for four adults.

    Happy soaking,
    David

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

Drafting the 2027 IRC

Key proposals for the next edition of the International Residential Code tackle room sizes, stair specs, emergency egress, and deck guards, among other requirements.

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

  • Podcast Episode 695: Saving Bricks, Cut-and-Cobble Insulation, and Waterproofing Foundations
  • FHB Podcast Segment: Waterproofing Below-Grade Foundation Walls
  • Midcentury Home for a Modern Family
  • The New Old Colonial

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