G'day and welcome back to Buildsum and as you can see today we're out on the site and what I want to show you
In this video is the process of constructing
What we call the subfloor frame
The floor frame itself and then putting down the flooring and this one's going to be what we call a platform floor system
so
as you can see here we've dug or excavated a strip footing around the perimeter of the building and
in the inside of the building we've got
holes for Blob footings and
We'll pour concrete in there shortly the next step would then be to place into the strip footing our reinforcement
Top and bottom of the footing just to strengthen that up
The blob footings don't require any reinforcement. They just sit there as a bulk concrete so
So we've done all the excavation so we can pour the footing
And it is there and you can see that it finishes below the ground level generally about a course
or 86mm or so
And what that does is when we put the brickwork up
We can then backfill over the top of the footing just so it's not seen
Okay, so that's our strip footing around the outside and our blob footings inside and once the concrete's set
Long enough now generally a week minimum
Then we can put up our dwarf wall, so our dwarf wall
Runs around the perimeter, and it's a funny coloured looking brick there hang on let me fix that
so the the wharf wall runs around the perimeter of the building site and
It has vents built-in for ventilation
and
it's just a single skin of Brickwork runs around the outside also has a
Hole there for our sub floor access door at a later date
now to reinforce the dwarf wall and
To also give us somebody bearers we have engaged piers
So these are connected to the dwarf wall with ties
Just wire ties or morse size they call them so that it can't separate and as the name suggests there engaged
to the dwarf wall okay there just the stack of bricks on top of each other
They're spaced so that they line up with where the bearers are going to sit
and
Generally evenly spaced the whole way around
There is an extra one here which is just there because that wall sitting there by itself because it's ends
So that's just there to reinforce that
So that's our dwarf walls with our Engaged Piers
We also have to have our isolated Piers
So these ones sitting out here by themselves
isolated or sleeper piers
Okay, and they're going to pick up the bearer when it runs through
So they're spaced the same distance as engage piers all determined by how far our bearer is going to span
Okay, engaged piers attached to the dwarf wall
Isolated piers out here in the middle. So that's our sub floor
frame if you like
I'll say yep subfloor. So what we need to do now couple of things have to put on top of our Brickwork
Firstly is the DPC or the Damp proof course
So nowadays. They generally use a plastic or polyethylene type Membrane commonly called Snakeskin because it's got a scaly looking effect on it
And while there does stops the moisture coming up through our brickwork and getting into our timber which then stops the timber from rotting
Also, the ventilation will help if any moisture does come up
or if the grounds wet here
Ventilation will help that dry out dry out
And that will stop that timber from rotting as well
The other thing that we have to take into consideration of their timbers
We need to have at least 400mm from the ground line to the underside of our bearer
that's got a couple of reasons 1. so we don't get moisture transfer and
2. it also it lets us get in underneath and crawl around and have a look for termites and stuff later on
I'll show you that shortly so the first thing we've put down is their Damp-proof course
All the way around make sure they overlap wherever you join them or at the Corners
So there's no way that any moisture is going to come up through the brickwork into the timber on
Top of the Damp proof course we have our ant capping
So it's simply a pressed metal generally galvanized
cap which has a
Turndown at the side, so it overhangs the Pier or the little dwarf wall has a turndown on the sides
And what that does is the termites just stops them from coming up
They can work their way up through the voids in the mortar and the bricks
And they call it if the cap wasn't here, just go straight through up here in there a timber
And you'd never know that were there by putting the cap there they can't eat their way through the cap
So what like you have to do is they come out to the outside of the cap underneath it
they then start to build mud tunnels, or they build them up from the ground and
They actually have to build mud tunnels out all the way around the cap and then into our timber
I've seen pictures of that. I've seen it happen
it does happen, but what it does is of course they've had to come outside of the pier
We can actually see them and with regular inspection, then we can stop them
So none of our termite systems that we have all hundred-percent stop termites
They only bring them out into an area where we can pick them up with regular inspections
So go have your ant cap, so there's full caps
for our isolated piers theres
half caps
for our engaged piers, and there's continuous lengths that go around for our dwarf wall and
they are all joined where they need to be joined with
well back in the bad days, old days they used to solder them
Nowadays there are caulking agents or like adhesives that a termite
Certified so you can use those and pop rivets to join the snt cap together
So now that we've got all that done. We are ready for our
Timber or our timber members the first one is going to be our bearer
So the bearers generally run the length of the longest dimension of the building so in this case this building is actually
Equal distance both ways, but we've picked around it this way, and we generally run at the longest dimension
And even though this is in shorter. We don't really want to turn around and run on this way
We'll just keep going the same way
You can join your bearers so obviously here. We've had to lap them. That's buy letting them run past each other
Over the pier and if we had to join say this one here we could butt joint them together
Just butting the two ends together and put making sure that's over and engaged pier
and then of course if your going to butt joint them it's not a bad idea to nail them together and
Some people slap a gang nail on both sides just to stop them from spreading apart
So they're our bearers, so the next member is our joists
Now because this is a platform floor
we have double joists on all our external walls and looks like
Forgotten one there's that me
throw that one in
so we're gonna have double joists on all our external walls and
Again if we're going to join our choice. We can
lap them past each other over a bearer or
if we need them to be in a straight line, we need to actually but them together again over the bearer and
Same again with the bearer you can always whack a gang nail or nail them together stop them spreading apart
generally speaking with our
Joists, they're spaced to suit our flooring so generally nowadays 600 or 450mm apart
If you're going to have a load-bearing wall in the internal part of the house
Then you need to make sure you have a joist underneath that wall
Okay, obviously the external walls are all going to be load bearings so they've got 2 joist under them
But for an internal load bearing wall it only needs
It only needs the one joist. I'll show that again in in a minute
And if it's a non load-bearing wall, you don't need any joist under it. I'll show that again as well in a minute
So there's our joists
You can then put down your flooring
Again this comes in sheet sizes 3.6 x 0.9 or 2.4 x 1.2
Depending on what you're using and because it's a platform floor it goes down before the walls are put up it runs all the way
underneath where the Walls going to go
And that's why it's a platform for it all gives us a beautiful platform to build the rest of the house on
And then the walls go up and as you can see here
Come back in
As you can see here our external wall
has double joist under it a
load-bearing
internal wall needs to have a single joist under it and
a
Internal non load-bearing wall can just sit in the middle of the flooring it's not required to have anything under it
So there you go there is a platform floor