# How to cut common rafters

Contents

- 1 How do you calculate Rafter cuts?
- 2 How do you cut rafters for a shed?
- 3 How do you cut a rafter with a speed square?
- 4 How big should Birdsmouth cut be?
- 5 What size rafters do I need for a 12 foot span?
- 6 How far can a 2×6 Rafter span without support?
- 7 Is 2 2×6 or 1 4×6 stronger?
- 8 Can you span 12 feet with a 2×6?
- 9 How much SPAN does a 2×6 need?
- 10 How far can you span a 2×6 header?
- 11 How far can a triple 2×8 beam span without support?
- 12 How big of a beam do I need to span 20 feet?
- 13 What size beam can span 24 feet?
- 14 How far can a 4X10 beam span without support?
- 15 What size steel beam do I need to span 30 feet?
- 16 What size steel beam do I need to span 12 feet?
- 17 What size beam do I need to span 10 feet?
- 18 What size beam do I need to span 15 feet?
- 19 How far can a 4×6 beam span without support?

## How do you calculate Rafter cuts?

## How do you cut rafters for a shed?

## How do you cut a rafter with a speed square?

## How big should Birdsmouth cut be?

When rafters are gang

**cut**, the saw’s**cutting**capacity helps determine**birdsmouth**dimensions; a 10 1/4-inch**Big**Foot saw is capable of making a 3-inch seat**cut**, which is suitable for a**wide**range of roof pitches and rafter**sizes**.## What size rafters do I need for a 12 foot span?

Max. Live Load 20 lbs/ft2 (956 N/m2)

Maximum Span (ft – in) |
||
---|---|---|

Nominal Size (inches) |
Rafter Spacing, Center to Center, OC (inches) |
Lumber Grade |

2 x 6 | 12 |
15′ – 9” |

16 | 13′ – 8” | |

24 | 11′ – 2” |

## How far can a 2×6 Rafter span without support?

**How Far Can**a 2×6

**Rafter Span**? A 2×6

**rafter can span**14 feet 8 inches when spaced 16 inches apart with No. 1-grade southern pine

**lumber**on a roof with a 3/12 slope or less with a maximum live load of 20 pounds per square foot and a deceased load of 15 psf.

## Is 2 2×6 or 1 4×6 stronger?

A

**4×6**joist is theoretically**stronger**than a doubled**2×6**joist because it’s**1**/**2**” thicker, but the actual strength depends upon the knots and other inherent weaknesses of any particular piece of lumber (#**2**lumber can have some nasty spike knots or large not-so-tight round knots or wane).## Can you span 12 feet with a 2×6?

In general terms, joists spaced 16 inches on center

**can span**1.5 times in**feet**their depth in inches. A 2×8 up to**12 feet**; 2×10 to 15**feet**and 2×12 to 18**feet**.**2×6**joists should only be used on ground-level decks that**do**not require, and will not provide for, any guards.## How much SPAN does a 2×6 need?

How far can a

**2×6**Rafter**span**without support? The table states that 2 X 6 rafters spaced 16 inches on center (o.c) can**span**a maximum distance of 13 feet 5 inches.## How far can you span a 2×6 header?

**Header**size required to support the roof, ceiling and

**one**center bearing floor of a 28-ft. wide building; 30-lb. snow load.

Figure B: Example of Calculating **Header** Size.

Header Size |
Maximum Span |
Number of Trimmers |
---|---|---|

Double 2×6 | 4 ft., 0 in. | One |

Double 2×8 | 5 ft., 0 in. | Two |

## How far can a triple 2×8 beam span without support?

**How far can a triple**2×8

**beam span**? In general terms, joists spaced 16 inches on center

**can span**1.5 times in feet their depth in inches. A 2×8 up to 12 feet; 2×10 to 15 feet and 2×12 to 18 feet.

## How big of a beam do I need to span 20 feet?

For

**20**-foot**spans**, the wood**beam**has to be at least 18 inches in depth.## What size beam can span 24 feet?

For example, for a

**24**foot wide house with a center floor**beam**, the total supported length of the floor joist is**24 feet**. Then you divide this by two to give a supported length of 12**feet**. This is the number you**will**use for supported length.)## How far can a 4X10 beam span without support?

Obviously, the larger the

**beam**, the greater the**distance**it**can span**between posts. A Redwood 4×6**beam should span**no more than 6′ between**supporting**posts.**How far** will a 4×12 **beam span**?

Joist Spans |
||
---|---|---|

Douglas Fir-Larch, Hem-Fir, Spruce-Pine-Fir, Redwood, Cedars, Ponderosa Pine, Red Pine | 4X10 |
5′-10″ |

4X12 | 6′-9″ | |

3-2X6 | 4′-6″ | |

3-2X8 | 5′-9″ |

Mar 25, 2021

## What size steel beam do I need to span 30 feet?

If you have a

**30**-foot**span**, it is important to know just how long a**beam**you will**need**for support. There is a good rule of thumb for this: divide your**span**(in inches) by 20. So, if your**span**is**30 feet**(or 360 inches) you**would**divide that by 20 to come to 18**feet**.## What size steel beam do I need to span 12 feet?

When it comes to residential projects like houses and smaller buildings, you can expect a

**steel beam**to be eight inches wide. This allows it to**span**as much as**12 feet**before you**need**another column.## What size beam do I need to span 10 feet?

A double 2×12

**beam**can**span**12**feet**; a (2) 2×10 can**span 10 feet**and so on.## What size beam do I need to span 15 feet?

For

**15**foot**span**,**size**of continuous**beam**for 2-3 storey residential building, using thumb rule, is about 9″×9″ in which**beam**width is 9″ and**beam**depth is 9″ providing with 2nos of 10mm bar at top, 2nos of 12mm bar at bottom and 2nos of 12mm crank bar of Fe500 with stirrup T8@6″C/C and M20 grade of concrete ratio (1:## How far can a 4×6 beam span without support?

A Redwood

**4×6 beam should span**no more than 6′ between**supporting**posts.