1. Ceilings & Basic Roofing
Revision
Created by Michael Martin March 2004 / revised April 2007

2. General Revision Textbook questions & answers Review A4 sheets
Components sketches
All calculation exercises ceilings and roofs

3. Ceiling Frames
Basic set-out of ceiling frame
Members & their function

4. Ceilings continued What is the function of a hanging beam ?
To support the ceiling joists mid-span, must be blocked at ends and a counter beam?
What is the function of the ceiling joists themselves ?
To support the lining material and also act as a tie between opposing rafters

5. Ceilings continued Also support to members
Review your worksheets from this section

6. Flat roofs Generally less than 10º pitch
More often ceiling joists and rafters all in one

7. Skillion roofs Walls at either end at different heights
Two ceiling types, raked and level

8. Lean to roofs Constructed against an other wall or roof Extensions
Carports
Verandas
awnings

9. Simplest method of marking skillion roofs
Scribe the birdsmouth

10. Gable roofs Members and their function Finish’s Calculations
Revise your worksheets for this section

11. Quick Questions What is the function of a purlin?
To give support to the rafters mid span
Where can a strut gain support from?
It either has to transfer it’s load to a load bearing wall or a strutting beam
What is the function of collar ties?
To stop rafters from sagging acting as a tie between opposing rafters above the purlin

12. Set out of common rafters
Can be done with steel square or
By calculation

13. Plumb & level bevel Remember where they are in relation to the roof
P28 of text handout

14. Transfer onto steel square

15. Gable definitions – Review handout
Span – horizontal distance overall the wall plates
Rise – vertical height from the x-y line to where the upper edge of rafters would intersect
½ span or run – plan length of rafter
Centre line length or set out length – the hypotenuse in the triangle, formed by the ½ span and the rise
Roof pitch – expressed in different ways, degrees, pitch ratio etc. see P56 of your handout notes

16. Other roof members – left to right
ridge
Wind bracing
purlin
Collar tie
strut

17. Other struts (this one is a half scissor)
Scissor struts

18. Gable end finishes
Flush gable
Verge overhang ?
Boxed gable ?

19. Extra members for boxed gables ?
With boxed gable ends you have
A bottom chord or tie piece
Also gable studs for fixing of linings
Or for ties to veneer skin

20. Calculations Review you worksheets
Review calculation sheets recently done in class

21. Now you can build this Test next week 5:30 to 7:00
Then class continues after dinner break.