55 / 68
5
3
CONSTRUCTION WORLD APRIL 2017 SASFA director John Barnard says that the successful training programmes undertaken by SASFA have been key in the promotion and growth of light steel frame building (LSFB) in Southern Africa. “Education is the foundation for getting the advantages of a new method understood as well as for protecting and enhancing quality of building through the growth phases and beyond,” says Barnard. The latest to come on board is the SANDF to whom, on their request, SASFA presented a 5-day training course for LSFB contractors at the Old Fort Rd Military Base in Durban. The intention of the course was to qualify their foremen and artisans in LSFB, in preparation for a building project comprising five three-storey blocks of flats and offices. The students of Regional Works Unit KwaZulu-Natal – under the command of Capt S. Mashigo – who enrolled for the course included, amongst others, plumbers, electricians, and project managers. Col E Jacobs coordinated arrangements for the course from the SANDF’s side, while the SASFA members who supplied support for the course and made it possible were Saint-Gobain, Martin and Associates, and Simpson Strong-tie. Bosch Tools illustrated its wide range of equipment suitable for use in the LSFB industry. BABCOCK 1/2While grinning may be unsightly, it is
unlikely to lead to further cracking. The
choice is to live with it, or to remove and
replace the plaster. Application of an
undercoat or a spatterdash coat before
plastering will help to avoid grinning.
Expansion
This includes swelling, softening, layer
cracking and spalling of the plaster. It
is usually caused by the inclusion of
Plaster popping as a result of expansion of ash bricks.
Debonding of plaster is often noticed as a hollow sound when the surface
is tapped. Pictured: debonding from an off-shutter concrete surface.
proprietary gypsum-based products in the
mix. Under moist conditions, the sulphate
from the gypsum reacts with the portland
cement paste and forms compounds of
increased volume which disrupt the plaster.
The only remedy for expansion-induced
disruption due to gypsum in the mix is to
remove and replace the plaster.
Popping
Popouts are conical fragments that break
out of the surface of the plaster leaving
holes that vary in size. These are caused
by the presence of contaminant particles in
the mix which, reacting with the moisture
in the mix, expand and cause cavities in the
plaster.
Contaminants are usually seeds, other
organic material, or particles of dead burnt
lime. Once the cause of the popout has
been removed, the hole can be filled with a
proprietary filler and painted over.