Are you tired of society you want to move to the bush
imagine designing and building your own cabin yourself
i can't really help you build your own cabin but i can help you to engineer it in today's
video i'm going to show you how you can engineer a cabin yourself in an easy way if you're not an
engineer the safest way to do that is by engaging a qualified structural engineer
you and only you are responsible for the decisions that you make having said that let's get started
i'm doing this video on my ipad therefore i'll screen record all the steps i may speed that up
a little bit and i'll be making comments on the important points this is the cabin we're going to
engineer together it's a timber framed home supported on joists bearers and posts
this is the front elevation finished ceiling will be 2.4 meters high side elevation the ground floor
plan it's approximately eleven by five meters two bedrooms one kitchen one bathroom and a veranda
before we get started with the design i'll quickly show you the structural elements that
we're going to design together so we're going to size floor joists which are horizontal members
used in framing to span in between bearers or walls and support the floor and walls above
a floor bearer supports the joists and are attached to the columns
now if we scroll down the
lintels lintel is a type of beam that spans openings such as doors and windows
rafter is a sloped beam used to carry the roof loads and the veranda beam is a roof beam that
picks up the rafters in a deck so now that we're familiarized with all the structural members
the first step to get the design started is to determine the wind classification for your site
this is a lightweight structure you don't want the wind to blow your home away that's why you
need to design the members accordingly there are a couple of ways you can determine the wind class
so first one is through as1170.2 second one is as4055 however since i'm trying to do this video
as straightforward and easy to understand as possible we're just gonna use live site design
guide and you can find it online easily so step number one is finding the wing region
since we we are in brisbane therefore region b
step number two is the terrain category and this describes the surface roughness around your side
so have a look at your site on google maps draw a 500 meters radius circumference around the house
and if the area is very exposed with no obstructions it is category 1. if there is
open water surfaces category 1.5 category 2 if there are some some obstructions
category 3 if you are in a suburban area and 2.5 is something in between three and two
so for our example i will choose terrain category 2.5
step number three is the shielding factor the wind speed is influenced by any obstruction
of similar size to the structure so full shielding is if the house is surrounded by at least two rows
of house usually disease in suburban developments partial shielding is where there are at least
2.5 houses trees or sheds per hectare and no shielding where there are no permanent
obstructions or less than 2.5 per hectare so let's suppose our cabin is surrounded by heaps of trees
which provide full shielding obviously i'm not going to lock the trees to build the cabin
so step number four is the topography effect and we're going to say that our site is flat
and the cabin is at mid third therefore t0 and finally we can determine the wind classification
using this table so it is region b um terrain category 2.5
topographic class t0 and full shielding therefore we have a n2 class
you will see a head that we need this wind classification to choose or design tables
next we're going to do the structural layout of our cabin starting from top to bottom we're going
to draw the roof framing which will be comprised of lintels where there are windows and doors
roof beams to the veranda and rafters spanning from wall to wall and from wall to roof being
l1 l2 l3 are the lintels rb1 is a roof beam and rr1 is a roof rafter
the lintels span in between jamb studs inside the wall and the roof beams span
in between hardwood timber posts which run from the footings all the way up to the roof
the floor framing will be comprised of bearers joists and timber posts
i've decided to break the spans by using more posts but you can adapt the layout
to suit your scenario it doesn't have to have all these posts
um so db1 stands for deck beam fb1 for floor beam fj1 are floor joists for the bathroom
where we have a set down and since you were since we're running the joists on top of the floor beams
i'll make fj1 at least 50 millimeters shallower than fj2 so we have the wet area set down
fj2 is a floor joists for the general areas
dj one are the deck joists tp1 is a 100 by 100 hardwood timber post and where fj1 runs
outside the bathroom area you will have to pack the floor to achieve the floor height
now we're going to start sizing the structural elements for this task i'll be using the tables
of the as1684 supplements for n2 wind class stress grade mgp12 starting with rafters we'll
have them spaced at 900 centers continuous span with the largest with the largest span of 3600
and we're using metal sheet for the roof of a mass of 20 kilos per meter squared
so if we look at the table this will give us a size of 120 by 35 mg p12 rafters
now for the lintels we need to know the span of each lentil
which is the opening size we need to know the roof load width and the rafter spacing having
these values we can find the size of the lintel for its maximum span on this table
so for instance l1 is only 900 long roof load width is 1800 and we get the size of
90 by 35 mgp 12. lintel 2 for example is 2100 long roof load width two four five zero
and looking at the table we will find the size 140 by 35 mgp 12. just a quick observation you
won't always find the exact numbers on the table so you gotta adjust these values to your scenario
l3 spans three meters and has the same roof load width of two four five zero from the table
we get 190 by 35 mgp 12. i'm gonna erase this
horrendous handwriting here and let's jump to the roof beam table
the roof beam spans approximately 3 700 and the roof load width is only 650 millimeters
so for a metal sheet roof of 20 kilos per meter squared of mass we get 140 by 45 mgp 12 roof beam
that's all for today folks in part 2 we're going to size the floor framing
wall framing bracing and look at the flames i hope you enjoyed the video let me know if you like such
videos or you wanted different topics also if you liked it share the channels with your friends
don't forget to like and subscribe to the channel thanks for watching and i'll see you next time