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

 DIY Chatroom Home Improvement Forum Rafter cutting calculations

02-11-2010, 09:34 AM   #1
Why not

Join Date: Feb 2010
Location: Houston, Tx
Posts: 49
Rewards Points: 25

## Rafter cutting calculations

Anyone know of any good forumlas for estimating how to cut rafters, etc. for roof framing

 02-11-2010, 09:56 AM #2 General Contractor   Join Date: Jun 2009 Location: Stafford, VA Posts: 534 Rewards Points: 500 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.

02-11-2010, 12:52 PM   #3
Member

Join Date: Dec 2009
Location: Edmonton, Alberta
Posts: 5,975
Rewards Points: 708

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

02-12-2010, 10:09 PM   #4
Member

Join Date: Feb 2010
Location: Oklahoma
Posts: 992
Rewards Points: 506

Quote:
 Originally Posted by noahweb 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.

 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 OffTrackbacks are Off Pingbacks are Off Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post scatkins Building & Construction 23 04-13-2010 03:20 PM 66mustang Carpentry 7 03-23-2009 12:48 PM darsunt Building & Construction 4 02-20-2009 08:22 AM wrldruler Carpentry 1 10-19-2008 06:03 PM jambud Electrical 17 03-12-2008 09:31 AM

Top of Page | View New Posts