Rafter Cutting Calculations - Building & Construction - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools
Display Modes
Old 02-11-2010, 10:34 AM   #1
Why not
 
Join Date: Feb 2010
Location: Houston, Tx
Posts: 49
Rewards Points: 25
Default

Rafter cutting calculations


Anyone know of any good forumlas for estimating how to cut rafters, etc. for roof framing
noahweb is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 02-11-2010, 10:56 AM   #2
General Contractor
 
Join Date: Jun 2009
Location: Stafford, VA
Posts: 534
Rewards Points: 500
Default


Pythagorean Theorem
C (rafter) = the square root of A squared (rise) + b squared (run)
Then subtract 1/2 the width of the ridge board (If the ridge board is of 2x stock subtract 3/4").
Then add the length of the overhang.

Other methods you can research are:

Unit-length method
Step-off method
Rafter tables

Easier method:
Purchase a Construction Master calculator and follow the directions supplied with it. There is also software available that will calculate everything for you and give you a cut list.
ARI001 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 02-11-2010, 01:52 PM   #3
Member
 
jlhaslip's Avatar
 
Join Date: Dec 2009
Location: Edmonton, Alberta
Posts: 5,975
Rewards Points: 708
Default


give us your span, pitch, wall style, ridge beam measurement, rafter size, over-hang, and all the rest of the information.

Roof Framing Calculator Ver. 4.5
__________________
Quote:
Short of cutting off a body part, the worst that can happen in woodworking is manufacturing really nice looking kindling. --- Quoted from lenaitch
jlhaslip is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 02-12-2010, 11:09 PM   #4
Member
 
Join Date: Feb 2010
Location: Oklahoma
Posts: 992
Rewards Points: 506
Default


Quote:
Originally Posted by noahweb View Post
Anyone know of any good forumlas for estimating how to cut rafters, etc. for roof framing
Read Carpentry by Ira Samuel Griffith....as well as the plethora of subsequent text out there in libraries and websites which cover this topic. And, when cutting rafters, don't estimate just calculate.
jlmran is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cutting rafter ties ?? scatkins Building & Construction 23 04-13-2010 04:20 PM
Cutting rafter 66mustang Carpentry 7 03-23-2009 01:48 PM
Cutting a bird's mouth cut in a rafter? darsunt Building & Construction 4 02-20-2009 09:22 AM
Moving Attic Access -- Same Rafter or Different ?? wrldruler Carpentry 1 10-19-2008 07:03 PM
2x100a sub on service main jambud Electrical 17 03-12-2008 10:31 AM




Top of Page | View New Posts