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

Math problem #2

StanFoster | Posted in General Discussion on September 21, 2008 06:43am

I am about to add on to my shop a new room for my helicopter.   The walls are 28 feet apart and 8 feet tall.  If these walls are EXACTLY plumb…that means they will not be parallel.  A vertical line on these walls should point to the center of the earth. How much wider do the top plates have to be over the 28 foot width the bottom plates are?  Its an infinitesimal amount..but one easily figured two ways.

Again…if a line on one wall is perfectly plumb…it will point to the center of the earth.   The other wall if also plumb…will also point to the center of the earth.  The top plates have to be further apart than the bottom plates to achieve this.

Obviously I wont be allowing for this…and also I apparently I have too much time on my hands while my eye is healing!

Stan

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

Replies

  1. geoffhazel | Sep 21, 2008 08:10am | #1

    looking like it as triangles, you have an isosceles triangle at the bottom of the wall with sides the length of the radius of the earth, or 20,925,196.9 feet long. The top is 28 feet. now you extend the legs 8 feet, and connect the top, and the length of the new top is

    20,925,196.9 + 8 / 20,925,196.9 times 28 feet

    (20 925 204.9 / 20 925 196.9) * 28 = 28.0000107 feet

  2. Hudson Valley Carpenter | Sep 21, 2008 08:17am | #2

    Stan,  it's a pleasant contemplation but why do you want a mathmetical answer?  Just imagining and sensing the lines of force is cool enough for me. 

    BTW, what kind of door system are you planning for your hangar?  Have you considering making your own bi-folds?  Goggle "hangar doors" for lots of options.

    1. StanFoster | Sep 21, 2008 02:06pm | #3

      Hudson:  Why do I want a mathematical answer?  Simply because there is one.  I am a numbers guy...though at a HS level...but if I know that say my walls technically will be wider at the top if truly vertical...then curiosity has me wanting to know how much.   I know it will be an infinitesimal amount..but I want to know the answer so I can relate to this amount. 

      I know what a 0.001 feeler gauge thickness feels like...and now that I know its a little more one tenth of that...I can relate to this. 

      Plus its a good exercise in honing my math skills...and the reward is the answer.    I dont know why I am explaining myself.  The question should be..."Why are you explaining why?  ha

       

      Stan

      1. Hudson Valley Carpenter | Sep 21, 2008 05:52pm | #4

        In my experience the more rewarding challenge is to meditate on the structure, whether in the abstract or, during the building process, in full scale...in order to feel myself a part of it. 

        When moments of connection with it happen, the feeling of atunement with the inner Self and the structure, as something derived from the same source, is life altering in it's beauty and simplicity.

         

      2. User avater
        jagwah | Sep 21, 2008 08:10pm | #5

        My initial thought was why, but then a non mathmatical answe would be to frame up the wall leaving the end studs off and the upper plates long. Using your plumb bob at the lower plates ends plumb up to the top plates and mark. Voila! if your plumb string and pencil mark are thin enough and the accurracy of your cut straight enough not to mention the squareness of the shoe of your saw you'll have a good accurately framed-to-the- curvature-of-the-earth-wall. All my framed walls follow the earths curvature.

        Since it's silly Sunday

        Bodes a question...Are there fewer stones along the top of the Great Wall then the bottom? 

         

        1. Danno | Sep 21, 2008 08:30pm | #6

          Wouldn't there be more?--wouldn't the wall be slightly wider (and longer) on top (if it were truly plumb)?

        2. User avater
          Sphere | Sep 21, 2008 09:24pm | #7

          Thats a trick question.

          Like when ya see geese flying in a VEE...one side is always longer than the other..why come is that?

           

           

           

           

           

           

           

           

           

           

           

           

           

           

           

          there's more geese on that side.Spheramid Enterprises Architectural Woodworks

          Repairs, Remodeling, Restorations

           

          They kill Prophets, for Profits.

          http://www.youtube.com/watch?v=Dj_oEx4-Mc4

           

          The world of people goes up and

          down and people go up and down with

          their world; warriors have no business

          following the ups and downs of their

          fellow men.

          1. DougU | Sep 21, 2008 10:18pm | #8

            I told that to my 6 year old son once and he punched my in the stomach!

            No more corney jokes I guess?

            Doug

  3. woodway | Sep 21, 2008 10:24pm | #9

    With those eyes of yours you will never be able to notice, pretend they are parallel and go for it.

  4. pm22 | Sep 21, 2008 11:16pm | #10

    This indeedy is a serious problem. It can be reasonably estimated with aclarity that 99.999% of the houses in the United States are architectually defective and substandard due to this profund deficiency.

    This 0.00001" difference between what is and what it should really be can be easily ascertained with a common micrometer. Any competent machinist can easily help you with this. Just measure your 28' with a Stanly Fat Max >30' size and have your buddy add the addional ten thousandth. [I think you can safely ignore the addional .00000007".]

    It should be noted that the use of plumb bobs [or Roberts] should be used with care due to the untowards possible deflexions caused by the proximity of nearby mountains which are less dense than valleys.

    Also, your cross joists with need an appropriate upward curvature to compensate for the roundness of this particular planet. However carpenters crown their joist so they've got this one right.

    ~Peter

    The two most famous female composers are Jean Sibelius and Camille Saint-Saens.

    1. Dogmeat12 | Sep 22, 2008 12:28am | #11

      "Just measure your 28' with a Stanly Fat Max >30' size and have your buddy add the addional ten thousandth. [I think you can safely ignore the addional .00000007".]"

      There is no way that I would or could ignore that "additional .00000007". I couldn't sleep at night.

       

    2. User avater
      jagwah | Sep 22, 2008 02:13am | #13

      Is all this mute due to elevation. Wouldn't the curvature be greater if like here in Tulsa were at about 600FAS? Or is the diameter you used a mean average?  

       

      1. geoffhazel | Sep 22, 2008 03:24am | #14

        normal elevation makes no difference in the results. You have to add 180 miles to the radius to change the last digit from a 7 to a 2. Even Mt. Everest's elevation doesn't change the last digit.

  5. andyfew322 | Sep 22, 2008 01:10am | #12

    what happened to your eye

     

    yep I change my oil every 3000
    miles or when I get bored...
    which ever comes first

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

Rescuing Old Hardware

Whether it’s already in your house or picked up at a flea market, vintage hardware almost always needs help.

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

  • Keeping It Cottage-Sized
  • Townhouse Transformation
  • Mortar for Old Masonry
  • Grout-Free Shower Panels

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 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
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers

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