Level 1 Diploma in Plastering

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

PowerPoint

presentation

Application: plumb and dot method of floating coat

Unit 124: Applying floating coats to wall

Level 1 Diploma in Plastering

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

Assessment criteria

1.4 describe the importance of correct technique and

procedure when using tools

1.5 describe different types of floating coats

2.4 use methods to apply floating coats

2.5 use correct techniques when applying floating coats

Level 1 Diploma in Plastering

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

Plumb and dot method

• The plumb and dot method is one of the most

traditional methods of applying floating coats, but

it is still used in high class work and on

long/high walls.

• This can be a very slow and time-consuming

method but it does ensure trueness.

• This method involves forming dots and using a

spirit level to plumb them in. Screeds are formed

from the dots.

• Not to be confused with the term ‘dot and dab’.

Level 1 Diploma in Plastering

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

Wooden laths are first

cut to 75mm in length

and then soaked

Application

Level 1 Diploma in Plastering

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

Application

• Apply a small amount of material in

the top right-hand corner,

approximately 150mm from the

ceiling and wall angle.

• Press lath into the material to a

thickness of around 12mm.

Level 1 Diploma in Plastering

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

Application

• Repeat this process to the top left corner.

• Place laths directly underneath approximately 150mm from the floor.

Level 1 Diploma in Plastering

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

Application

Once all laths have been pressed

into place, a spirit level and straight

edge are used to plumb them.

This is when the correct thickness

is also set.

Level 1 Diploma in Plastering

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

Plumb and dot method

Dots should be

cleaned off and

allowed to stiffen

up.

Ruling off the laths,

screeds can be

formed.

Level 1 Diploma in Plastering

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

Application

Laths can be removed and screeds

rubbed up.

Allow screeds to stiffen up.

Level 1 Diploma in Plastering

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

Application

Starting in the top

corner, fill in between

the screeds, using the

screeds as a guide to

rule off any excess

material

Level 1 Diploma in Plastering

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

Application

Once the whole wall

has been ruled in and

is sufficiently stiff, it can

be rubbed up before a

suitable key is applied

Level 1 Diploma in Plastering

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

Application

On high walls in may not be possible to use a spirit

level and straight edge

In order to set the dots, a plumb bob and gauge laths

would be used

A gauge lath is a piece of timber cut to measure the

protrusion of the dot

Using an identical lath on the lower dot, the plumb bob

should touch in the same point

Level 1 Diploma in Plastering

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

Upper gauge in position

Gauge

Plumb line

Plaster dot

Lath

Level 1 Diploma in Plastering

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

Lower gauge in position

Level 1 Diploma in Plastering

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

Dots being lined in using a plumb line

Level 1 Diploma in Plastering

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

Any questions?