Civil Engineering Reference
In-Depth Information
The carrying capacity of the wall is dependent on the dimensions of the studs and
wall plates as well as the strength grade of the timber. Your engineer or building
consultant can establish the timber specifications. The details of the timber to be used in
the walls will be specified in the timber specifications that form part of your building
permit.
Using non-structural timber legally
It is possible to use the new non-structural timber legally to reduce costs in a number of
ways. Timber is graded relative to its load capacity. These days, most timber framed walls
in Australia are built from Radiata Pine. The most common strength grading of radiata
pine is MGP which stands for 'Machine Grade Pine.' What was previously referred to as
F5 pine is now MGP10 and F7 is now often referred to as MGP12 pine The higher the
reference numbers the greater the strength of the timber. When constructing your house,
it is important that you use the correct grade of material as specified in the timber
specification section of the building permit. The lowest grade of timber is non-structural.
This timber can often be purchased at a significantly lower price than other grades of
materials. The use of this material is not only financially beneficial but also ecologically
responsible. MGP10 pine is the most popular material used in conventional building and
so it stands to reason that the demands on this product are most likely the driving force
behind the felling of pine plantations. The more non-structural material that can be used,
the better use we are making of all the timber milled. If no one were to use the non-
structural material it would have to be destroyed.
There are many applications in the construction of a house that do not require
structural timber. When the roof of a house is built using roof trusses, all of the weight of
the roof is transferred to the external walls. With this type of construction, any internal
walls are basically installed as partitions and with some exceptions do not form a
structural part of the construction, as they do not carry any load. In these situations the
use of non-structural timber is appropriate. If you want to take advantage of the cost
saving and ecological benefits of using non-structural timber, be sure to advise your
engineer and/or building consultant. Standard practice is to specify stress-graded timber.
If you do not advise them otherwise this is what will happen.
The process of constructing walls
The task of establishing wall lengths and their positions within a house can be very
difficult if gone about in the wrong way. The excitement of the moment often overtakes
owner-builders who set about building their first wall as soon as possible. Building walls
as individual units is fraught with traps to catch the unsuspecting so PLEASE take note of
this section. On more than one occasion owner-builders have built their walls one at a
time and then found they simply do not fit together.
One of the processes in constructing timber framed walls is the marking of the wall
plates to indicate the position the studs are to be fitted. The wall plates are the horizontal
timbers at the top and bottom of a timber framed wall. This wall plate marking includes
the studs at the sides of openings such as doors. To calculate the required width of the
opening for a door you will need to know the width of the door to be fitted and the
