Direct Method Presentation This Presentation was prepared by
13 Slides261.50 KB
Direct Method Presentation This Presentation was prepared by John Bridges Of SWSI TAFE Granville college 2004
Developing Bevels using the Direct Method
This Slide Show is to be used to explain the methods of Directly Developing the bevels required for a HIP AND VALLEY ROOF Students are to complete their own drawings as the facilitator progresses through the show
Step 1. Having previously obtained your Plumb Bevel from a Pitch Board Setout. Start 100mm from one end and mark the Plumb Bevel 100mm Edge 1. Face 1. Plumb Bevel Common Rafter ‘T’
Step 2. Transfer the thickness of the timber to parallel the Plumb Bevel Step 3. Mark a line at 90o to the Plumb Line. Edge 2. ‘T’ Face 2. Level Bevel Common Rafter NOTE: This triangle is in proportional to the rise per metre run of the roof The thickness of the piece of timber represents the run or half span of the roof. ‘T’
4. ½ 3. Span Step 4. Mark a line square across the thickness of the timber from the point of the Level Bevel Common Rafter Face 3. Edge Bevel Creeper 4. Edge Bevel Purlin Step 5. Join the end of this line back to the point of the Plumb Bevel Common Rafter to form a Right- angle triangle Edge ‘T’
Step 6. Extend the ½ Span line at 90o to the rise on the opposite side of the Common Rafter Step 7. Transfer the length of the Hypotenuse of the Edge Bevel Creeper and Purlin triangle Edge 5. ip 6 H h . engt n Pla Face L Step 8. Join this intersection point to the top of the Rise 5. Plumb Bevel Hip 6. Level Bevel Hip ‘T’
Step 9. Transfer the Plumb Bevel Hip to the other end of the timber by setting a sliding Bevel to the Plumb bevel Hip. Edge Face
Step 10. As for Step 2 transfer the thickness parrel to the Plumb Bevel and create a Right-angled triangle starting at the intersection of the edge with the thickness. Edge ‘T’ Face ‘T’
Step 11. Mark a line square across the thickness of the timber from the point of the Level Bevel Hip Step 12. Join the end of this line back to the point of the Plumb Bevel Hip to form a Right- angle triangle Edge 7. Face 7. Edge Bevel Hip
Step 13. Select a point along the True Length Common Rafter and mark a line down the face at 90o from the edge Step 14. Mark another line at 90o across the edge Step 15. Transfer the length of this line down onto the True Length Common Rafter and connect back to the intersection on the Plumb Cut Edge Face
The Face Bevel will be formed in the top corner of the triangle where it intersects with the True Length Common Rafter Edge 8. Face 8. Face Bevel Purlin
An alternative practical method to obtain the Face bevel Purlin is to cut through the Plumb and Edge cut for the creeper, then cut off the point square across the edge and face. The shape formed will provide the Face Bevel Purlin in the top corner