C&G PowerPoint Raking mouldings

Level 3 Diploma in Site carpentry

© 2013 City and Guilds of London Institute. All rights reserved. 1 of 10

PowerPoint presentation

Setting raking mouldings

Unit 307: Carry out second fixing double doors and mouldings



Overview

• Describe methods used to set out raking mouldings.

• Outline why projections change from horizontal to raking.

• Identify problems where the developed moulding are not used.



Raking mouldings

• When mouldings meet at a mitre and one of the mouldings is horizontal while the other moulding is inclined, the profiles of each will need to be different.

• The moulding that is inclined is called a raking moulding.

• The process of achieving the correct profile through geometry is the same, but reversed depending on whether the horizontal or the raking moulding is given.



Finding the profile of the raking moulding: non-geometrical method

Geometry will give the most accurate profile for reproducing the moulding but non-geometrical means can also be used. This is useful if you only need a short length and it can be made by hand.

1. Use the wall or a block of timber to represent the wall.

2. Mitre the horizontal moulding as usual.

3. Offer up the raking moulding to the mitre.

4. Plot the profile from the horizontal moulding onto the raking moulding.

5. Use these points to mark parallel lines along the raking moulding.

6. Work these lines with hand tools to achieve the required profile.



Developing the true raking profile shape

In this example we are required to mitre a moulding at the lower end of the raking as in pediments around a door. We are given the horizontal profile and need to develop the raking profile.

1. Divide the profile into any number of parts. The more parts, the easier it is to reproduce curves, but it could become confusing. In this case we have seven.

2. Project parallel lines upwards along the raking angle at each point.

3. Project vertical lines upwards from each point.

4. Cast a horizontal line from the raking moulding at point 7.

5. With point 7 as the centre and vertical projections 1 to 7 as radii, describe arcs to cut the inclined mould.

6. From these points draw perpendiculars to the rake.

continued…



Developing the true raking profile shape

7. Use the points where the perpendiculars meet the parallel lines to the inclined moulding to produce the true mould shape.

8. Draw through the intersection point to reveal the finished profile shape.

Reverse the process if you have to develop the horizontal moulding.

The blue outline is the new projected profile.The orange profile is the given raking profile.



Producing the top horizontal profile from the given raking profile

• If the moulding needs to continue above the raking on a horizontal plane, the same principle is used to develop the new profile.

• As can been seen when viewing the two projected profiles, the lower profile becomes more pronounced and exaggerated while the upper profile becomes elongated and substantially bigger.



The orange outline is the new projected profile.The blue profile is the given raking profile.



The blue outline is the new projected profile for the top and bottom horizontal.The orange profile is the given raking profile.



Any questions?

Date post:	21-Jan-2017
Category:	Education
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C&G PowerPoint Raking mouldings

Education