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Level 1 Diploma in Plastering

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Application: broad screed method

Unit 124: Applying floating coats to wall



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



Application

• When floating, it is important to prepare the work

area, tools and equipment before starting work

• This will make it easier for you and will ensure

that the wall is applied in an even manner to

create a flat and even surface



Place the mixed plaster on

a pre- wetted spot board

• If the spot board is too

wet, the plaster will slide

off

• If it’s not wet, the plaster

will start to dry out

Application



Application

Tip: It is a good idea to wash all the mixing

equipment so that you are ready to mix the next

batch!

Water can be poured ready to mix.



Application

When floating, it is good practice to work heel to toe

of the trowel.

Right to left for right-handed plasterers

Left to right for left-handed plasterers

This means that you are always working towards

your last application.



Application

Each trowelful should overlap the last one

slightly and an even amount of pressure should

be used

Try to build up the thickness required in short

strokes



Application

• Start in the top corner of the wall and work down the wall angle

• Ruling from the angle outwards approx. 200mm

• Check with spirit level and fill out where needed



Application

• Now fill out the

opposite angle

• Ruling out from the

angle approx. 200mm

• Check with spirit level



Application

• Apply material along the

ceiling line

• Ruling from the ceiling

angle

• Ruling in line with the

vertical screeds



Application

Apply a final band along the

skirting line approx. 150mm

high.

Now all of the angles

should be straight!!!

Note: Plastering material

should not go down to the

floor!!



Application

The screeds should be left for a short period of

time before being rubbed up and the hollows

filled.

A key can be applied to the bands.

www.youtube.com/watch?v=Mx5SY5ElL9M



Application

The middle section can now be filled in ruling off all the

screeds.

The area should be ruled in every direction, taking off

the excess and filling in the hollows.

www.youtube.com/watch?v=GodQJRnhtT0

www.youtube.com/watch?v=7wz0Q9vK-ME



Application

Once the material starts to

set (‘pull in’), the wall can be

flattened and the hollows filled

in.

Use a float to rub the wall up.

www.youtube.com/watch?v=e-jZYJBwBq4



Application

The wall can now be

given an appropriate key.

Use a devil float and

give a ‘figure of eight’

key



Application

Overall, the floating coat should be approximately

between 8mm and 12mm thick.

British Standard for internal plastering states that

no more of a 3mm deviation in a 1.8m rule is

allowed.



Did you know?

Cracks can appear on the surface (shrinkage).

This is caused by the suction in the background and

the plaster drying out.

The background joints can appear through the

surface (grinning).

This is caused by the plaster being too thinly applied

or variations in suction.



Patching a chase

Plastering after

electricians mainly

consists of filling chases

left from fitting wires to

walls.

The plaster should be

removed back to a solid

area before being filled

with bonding coat plaster

and ruled in flush with the

existing plaster.



Patching a chase

Once the plaster has set, it should be cut back

so that when the finish is applied, it will blend

in with the existing one and not leave a ridge.



Any questions?

Date post:	18-Feb-2017
Category:	Education
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