G'day and welcome back to Buildsum, and this is presentation 24 on the series on the timber framing code or
AS1684 and in this one that we're going to look at our lintels
So the rules for our lintels 6.2.3 and 6.3.6 and
The table we're going to use is Table 17
So 6.2.3 openings openings
shall be framed with jamb studs and lintels or heads or
Ring beams. We're required Jack studs shall be the same size spacing and orientation as the common studs
alternatively Jack studs may be made up by horizontal nail lamination a
minimum clearance of 15mm shall be provided between the underside of the lintel ring beam or
lintel ring beam trimmer and the top of the window frame or door frame
Continuous lintels may be located directly below the top plate
Where the breadth of the lintel is not the full depth of the wall frame all studs shall be housed around the lintel as
Shown four Jack studs alternatively a continuous ring beam may be used without a top plate
Above providing it is designed as a standalone member without
secondary contribution of a top plate
6.3.6 says that top plate shall be
Provided above lintels ribbon plates may be provided above ring beams
adequate
Bearing of lintels and ring beams shall be provided
as required by the notes to the span tables given in the supplements actual openings
May be up to 70mm greater than the maximum spans given in the span tables
So
6.3.6.2 says the size of lintels in load-bearing walls shall be determined
from span tables 17 and 18 of the supplements
For a single story or up a story of a two-story construction or from tables span tables should be tables
47 or 48
of the supplements for the lower story of a two-story construction for sheet and tolerance respectively so
As I said before we're gonna use Table 17
Here's Table 17
And you can see the information you need you need to know the roof load widths ours was 1800
So we're gonna use the 3 meter column
Well, sorry use the 3000 column now rafter trough spacing is 600
So I'm gonna use a 600 column
And then we're going to know what the maximum width of
Our lintel is a maximum span of our lintels is so we need to get back to our
Door and windows schedule to find that maximum width you'll remember this
From the studs at the sides of openings so our first one 1800 wide
So let's go and have a look at 1800. I've giving it away
So 3000 roof load widths
600 s[acing and we'll go down I could use
Go back I could use 2 /90 x 45 but
1/120 x -35
is gonna be far more efficient, so I'm gonna say I'm gonna use one 120 x 35 for my
Lintel over that first window
So put that in there and anywhere else we've got 1800 we can put it in there as well
so 120 x 35 in there
Let's go back to the next one sorry
The next one down was 1200
So we can come down
Remembering our columns
So a 90 x 35 will do up to 1400 so we can use
That in there, so we need is 90 x 35 for a next one
So 90 x 35 for 1200, 1200 there
anything up to
1400 well is it yep anything up to 1400
So a 1350 we can use it
90 x 35 there 90 x 35 there and there
So next one down
1650
So we could use
1700 so that's
1650
could use
2 / 95 x 35
But I suspect
You can't go up to a 90 x 45 because it drops the end of 1500
So the next one up that we have to use to be more efficient. Let's go back to our 120 x 35
Could use 2 /90 x 45
But a 120 x 35 here me more efficient, so we'll use that one
So 120 x 35 in their first 1650, and now we're going to go up to our 1850
So again
Using our columns we could use first one
Comes available this is 2200 there
We could use 2 /120 x 35
However, I feel that maybe a little bit of overkill
So let's look at the next one when I name can't use that oh, we could use that
It could use a 1900 we could use that one there
The 120 x 45, but I've pretty sure the 140 x 35 will have a more
smaller sectional size
And it will be a more efficient member to use so we're going to use a 140 x 35 for our
1850 openings so there you go, we've got the lintels for our our building