Unit 3 - Roof Trusses

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KEY CONCEPTS

1. Identify tools needed for rolling trusses

2. Identify proper nails and sizes

3. Setting roof trusses

4. Site Safety and Hazards

INSTRUCTIONAL ACTIVITIES

1. Complete Follow Up Worksheet from Unit 2 Framing

2. Identify tools: students discuss use of each tool

3. Identify and discuss different roof designs

4. Discuss hip roof truss components and setting of trusses

5. Discuss hurricane clips

6. Discuss the function of fascia and how it is installed

7. Common roofing hazards and safety issues

8. Summarize Key learning points

ASSESS LEARNING OF KEY CONCEPTS

Students will need to demonstrate knowledge of hip roof design and truss layout, function of hurricane

clips, and function and proper installation of fascia.


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TOOLS USED

A. Pry Bar F. Reciprocating sawB. Cats Paw G. Speed SquareC. Hammer H. LevelD. Circular Saw I. Chalk LineE. Power Miter Saw J. Tape Measure

K. Sledge Hammer K. Trus-Lock (not pictured)

MATERIAL S USED

A. Trusses D. Hurricane clipsB. 8d nail E. 2x6 fasciaC.16d nail F. 16d galvanized nails

G. 1" tico nails

D

CB

E

A

KF

I

JH

G


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Truss ID Truss Type

C24 Common

H24A Cal Hip

H24B Cal Hip

HM24 Hip Master (or Girder Truss)

HR1 Hip Rafter

J 10 J ack

J 12 J ack

J 2 J ack

J 2A J ack

J 4 J ack

J 4A J ack

J 6 J ack

J 8 J ack


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Wood trusses are pre-engineered and shop made. Trusses are typically constructed of 2x4s and 2x6s. Truss members are connected with metal gang-nail plates Roof elements are applied directly to the top chords. Ceiling (drywall) may be applied directly to the bottom chords.


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Steps to setting the shed roof trusses is shown here.


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SETTING ROOF TRUSSES

1. Our truss design is dependent on deciphering the plans that come from the truss manufacturer.Of importance is the location of the girder truss (hip master) that the jack trusses will be attached to.

There is a specific order and place for the trusses so please take the time to understand whereeverything goes. See diagrams on page 7.

2. One key to reading the plans is knowing the numbering system. On page 4 the numbers 5-11-4 on the trusslayout means 5 feet, 11 inches, and4/16 or inches.

3. Place the girder truss (or hip master) in its location and attach the center jack truss to keep the girder trussfrom tipping over. String line the bottom of the girder to keep it and the jack trusses straight.

4. Consult the layout that came from the truss company, but most of the time the layout for the jack trussesstarts from the corners and is every 24" to the center of the truss. This is from each corner, so the plywoodwill have a funny layout when you get to the center.

5. The main trusses are every 24" on center from the girder truss toward the other girder truss.

6. After the trusses are installed, the fascia board that the rain gutter attaches to can be installed. See diagramon page 9. Fascia is attached with galvanized 16d nails. Fascia can be cut on an angle to match the roofslope.

7. Some of the material we will be putting up will be pre-painted. Anything that will have an exposed nailhead needs to be galvanized.

8. After the trusses have been installed, the hurricane clips may be installed. Use the 1" tico nails. Needlenose pliers may be helpful to hold nails in tight places.


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Placement of sub-fascia,

fascia, soffits, and insulationbaffles is shown here.


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SAFETY GUIDELINES FOR ROOF TRUSSES

A.This is a hard hat day!

B. Use safety equipment such as glasses, earplugs, gloves, etc to minimize the risk of injury.

C. Do not wear jewelry at the work site. J ewelry, long hair, and loose fitting clothes can getcaught in saws. Sandals and flip flops are not allowed on the work site.

D. Use caution when lifting and get help with lifting heavy items.

E. Use extreme caution on ladders and scaffolding; work at a height you are comfortable with.

F. Immediately remove nails from used boards.

G. Do not use unfamiliar power tools until you have received proper instruction.

H. Be aware of your surroundings and watch for holes, trip hazards, and other people.


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FOLLOW ALONG WORKSHEETPlease use the area below to take notes about the major subject headings listed.

NEW TOOLS:

TRUSS COMPONENTS:

MAJ OR STEPS IN SETTING ROOF TRUSSES:

ADDITIONAL NOTES:


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FOLL OW UP WORKSHEET:

Fill in the Blank:Please fill in the blank of each question with the corresponding answer from the key below.

1. ____________ help attach the roof to the frame of the house.

2. Galvanized nails are used anywhere there will be an ____________ nail head.

3. A hip roof has __________ surfaces.

4. ____________ are spaced 24" apart center to center.

5. ____________ attaches to the ends of the trusses and is what the rain gutters are attached to.

Identify:Please explain the difference between a girder truss and a jack truss.

Choose one safety precaution particular to this unit that you can implement either on the job site or in yourhome. In the area below describe why this precaution is necessary to ensure safety.

Hurricane clips Exposed Fascia

Roof trusses Four

Documents

Unit 3 - Roof Trusses