building construction 3 - Lecture 7

1. PLASTERING AND DRY LINING
Building Construction III
Spring 2012
Dr.Hikmat Hammad
Lecture 7

2. Dry lining
• It is covering the wall surfaces by plasterboard,
strawboard, fiberboard, plywood or similar sheet
materials.
• This method reduces the construction time,
simplifies the work and improve the quality of the
finishing.
• By dry lining insulation and fire resistance values
of a wall can be improved by incorporating
suitable materials.
• A lot of defects which might happen in plastering
can be eliminated by dry lining.

3. • Most common method is using plasterboard
as lining material.
• Plasterboard consist of an aerated gypsum
core sandwiched between two strong paper
liners.
• Most plasterboards have one surface ivory
and the other gray colored paper.
• Only gray color surface is suitable for the
application of board plasters.
• The other surface is ready for direct
decoration.

4. • There are different sized plasterboards
available:
• Wallboard: it has several standard sizes but the
most popular size is 240*120 cm. thickness 9.5
or 12.7 mm. there are both sides ivory colored or
one side ivory other side gray color types.
• Plank: it has a size 240*60 cm with thickness 19
mm. surface finish is same as wallboard. It is
mainly intended for fire protection of structural
elements, and lining for doors and partition walls
where sound insulation and fire protection is
rather important.

5. • Lath: it has a size 120*40.6 cm with thickness
9.5 mm and 12.7 mm. with shorter length and
narrow width it is used in places of difficult
access such as ceilings.
• Baseboard: it has a size 120*91.4 cm with
thickness 9.5 mm. and it is alternative to lath in
ceiling lining works.

6. Method of applications
• Lining walls with plasterboard is made in
three ways:
– Fixing on timber battens
– Fixing on metal channels
– Plasterboard bonding

7. Fixing on timber battens
• In this method timber battens of 40*20 mm are
fixed vertically on wall with 40-5- cm spacing
suitable to the type of plasterboard.
• Plasterboards are fixed on the battens by
galvanized steel nails with suitable lengths
according to the board used at 15 cm spacing.
• The joints between the boards and external and
internal corners are specially treated with joining
tape and filler.

10. Fixing on metal channels
• In this method plasterboards are fixed to
galvanized steel or aluminum channels by
self-tapping screws at about 30 cm
centers.
• Metal channels can be fixed on surface of
brick or block walls by plaster dabs or nails
or they can be the elements of stud
partition walls

12. Plasterboard bonding
• Bitumen imp fiberboards pads are fixed to
the background with adhesive. After the
pads are aligned and firmly secured
bonding or board finishing gypsum plaster
are trowelled on between them.
• The boards are firmly placed over the
dabs. It is supported until the plaster sets.
• The joints are again treated to make the
two sides level.