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Lesson 4 Levelling a Ceiling

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Levelling a Ceiling

Learning Outcomes

Recognise a Datum Line Describe how to level a ceiling Identify a levelling cradle, and its uses

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Question Discuss among your group and write down your

answers for the following questions1. What is the point of levelling a ceiling ? 2. On what kind of work would it be beneficial to

perform this particular task?You have five minutes for this task Answers1. To provide a true level surface for running in -

situ moulds on2. Every time you are running a mould an in-situ

mould

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Levelling a Ceiling

A Datum line is a level line

Snap a level datum line around the room about 225 mm from the ceiling.

If the room contains a beam, snap the line below the soffit of the beam.

Select a point on the ceiling about 150 mm in from the wall that looks as if it is the lowest point of the ceiling.

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Levelling a Ceiling

At this point, place a dot with a lath or piece of plasterboard bed on.

Hold a square onto the floated wall and the dot. Tap the dot in or pull it out until the square sits squarely on the wall and the dot

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Levelling a Ceiling Having positioned the first

dot, a mark is made on the square in line with the datum point.

Further dots can be positioned on the ceiling and lined up with the marks on the square and the wall

Screeds can now be formed between the outside dots and the intermediate dots.

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Levelling a Ceiling

The ceiling can then be floated and ruled in to a true, flat surface

Devil and consolidate the floated surface and put on a finishing coat when the material has set.

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Levelling a Ceiling Concrete beams or

plasterboard beams are floated to increase the fire rating (especially with plasterboard beams that are encasing a steel structure), also to improve the straight lines of the beams themselves.

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Levelling a Ceiling

The floating of a beam is not too dissimilar to floating a ceiling.

The beads can be squared in from a floated ceiling (as described earlier) by holding the square flat onto the ceiling and marking the square, where it touches the bead, at one end of the beam.

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Levelling a Ceiling

As long as the ceiling is true and flat, the square can be held along the length of the bead at regular spacing, so that there is equal distance between the angle bead and the ceiling.

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Question You have been sent on a job, the job involves levelling a ceiling which has two beam running across , you notice that the ceiling is at different height between the beamsHow can this be achieved without using a datum line or a laser level?

Beam Beam

Ceiling at different heights

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Levelling a Ceiling

Beam

Spirit Level

Levelling Cradle

A Levelling Cradle is used when the ceiling has to be levelled around a beam.

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Levelling a Ceiling

Beam Beam

Levelling Cradle

Spirit Level

Bonding Compound

Plasterboard Dots

Chalk Line

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Recap What is a datum line Answer A Datum line is a level line How do you level a ceiling Answer By using a series of dots and screeds set from a

datum line What is a levelling cradle Answer A Levelling Cradle is used when the ceiling has to

be levelled around a beam.