Cover Image
close this bookCarpentry for Vocational Schools - A Teacher's handbook (GTZ, 252 p.)
close this folder13. ROOFING
View the document(introduction...)
View the document13.1. Different roof shapes
View the document13.2. Technical terms of a roof
View the document13.3. Rafter and ridge roof
View the document13.4. Roof truss
View the document13.5. Diagonal roof bracing
View the document13.6. Roofing iron
View the document13.7. Laying of roofing iron
View the document13.8. Finishing a roof

(introduction...)

TOPIC: 13. ROOFING

INTRODUCTION: This topic teaches students the different roof shapes; the names of the parts of a roof; how a roof truss is calculated, made, erected and braced; the proper distance for purlins; roofing iron and different types of roofing fasteners; laying of roofing iron, ridge cap and finishing roof.

This topic is very comprehensive. therefore select carefully the chapters you are able to fit into the yearly programme at the school.

OBJECTIVES:

13.1. Students should be able to distinguish between the different roof shapes and their characteristics.

13.2. Students should be able to name all the parts of a roof.

13.3. To know when a rafter or ridge roof is needed, their technical terms and how they are made.

13.4. Students should know the names of the parts of a roof truss, how the height and the number of diagonal members are calculated, how a truss is made and assembled and how the trusses are erected.

13.5. To know the purpose of braces and how they are fixed correctly.

13.6. Students must know the size of the roofing iron and be able to space the purlin correctly.

13.7. Students must be able to describe how roofing iron is laid and fastened correctly.

13.8. Students should be able to finish a roof by laying the ridge cap, fixing fascia and barge board and hanging the gutter.

METHOD This topic is taught in the classroom first. We prepare photocopies of the drawings of this topic and students glue it in their trade theory book. We also prepare some roof models for better understanding.

13.1. If there are buildings with different

13.2. roof shapes near the school, show them to the students and let them name their parts.

13.3. Prepare the timber for a model of a rafter roof in the scale 1:10 and construct it with the students.

13.4. If we cannot demonstrate the process of making a roof truss on a building project, we can again use our model house and prepare timber for a roof truss In the scale 1:10. Explain how to do this work step by step.

13.5. Prepare some small strips of flat iron and allow students brace the roof of the model house correctly.

13.6. Prepare the timber for the purlins in the scale 1:10 and students place the purlins on top of the trusses and nail them. Show students how purlins are straightened properly.

13.7. Prepare some pieces of flat iron which are to be used as roofing iron for the model house and let students follow the procedure they have learned in the theory lesson.

13.8. Prepare small flat irons to use as ridge cap for the model house and timber in the scale of 1:10 for fascia and barge board. Students can complete the roof now.

NOTE: Because of the size of this section it is advisable that at least two worksheets are prepared for students, to complete in their own time.

The main purpose of any roof construction is to carry the weight of the covering material which prevents rainwater from entering the building and protects the inhabitants from sun and wind.