Wednesday, June 18, 2014

Brick Veneer Platform Floor Section Part 3

To see what happened before this go to Brick Veneer Platform Floor Section Part 2

Now we need to get the Bricklayer in to run a couple of courses of brickwork until it is about a course below the bottom plate.

Vermin wire is run from the bottom plate and bedded into the brickwork so that Vermin can't get up into the wall cavity from the floor space.

The Brick veneer is tied to the timber frame every 4th course using veneer ties. 

The ties are nailed to every stud slightly above the brick and then bent down so it can be bedded into the mortar. This will ensure that any moisture or water that runs down the back of the brick will stay against the brick until it hits the flashing and exits via the weephole.

The brickwork should be laid to a ‘bond’ so that it finishes around 10mm below the ‘Drop Off’. 

Below the window the brickwork should finish 2 courses down to allow for the sill bricks and the flashing that is attached to the window should be embedded into the brickwork as well.

With the brickwork complete the eave frame can be built. There are a few different styles of eave that you could have, the one shown here is a Boxed or Level Eave.

The finished eave should finish around 10mm above the brickwork to allow for the timber frame to settle overtime. 

A quad or similar moulding is used to cover the gap and still allow for the movement.

With the outside finished the work inside can really start. Internal linings such as Plasterboard can be installed. 

Plasterboard can also be used on the ceiling and the intersection covered with a cornice moulding again made from Plasterboard.

Architrave is used to cover the gap between the window jamb and the wall and a Skirting mould use to cover the connection between the wall and the floor.

Brick Veneer Platform Floor Section Part 2

To see what happened before this go to 'Brick Veneer Platform Floor Section Part 1'

The timber frame which is the load bearing skin of the wall is constructed next. This can be constructed onsite or more commonly nowadays constructed at a frame and truss factory and delivered to site.
To see more on this process watch these videos:

The walls are stood, plumbed, braced and tied down ready for the roof.

Again there are several options at this stage. Trusses are a common method of constructing the roof.
To see more on Trusses watch this videos ‘Truss roof erection’
Or you could go with the option of the cut on site option.
To see more on this process watch these videos:

Once the roof is on then the Fascia can be installed. The Fascia was traditionally timber and is still available in lengths of finger jointed pre-primed pine however a metal fascia is now more common as it is quicker and easier to install and does not require painting.

 Now that the Fascia is on the Roof covering can be placed, again there are options at this stage namely a Metal roof,‘Colourbond’, or Tiles. Both methods require the installation of battens for fixing the covering to the roof. 

With tile roofs the first batten is different to the rest. It is called a Bellcast batten and it sits taller than the others to kick the first tile up so it sits at the same angle as the rest of the tiles.

A layer of sarking or sisalation can also be installed at this point. This is not mandatory but something that I prefer. The sarking provides a backup layer in-case water is blown through the joins in the tiles or can be combined with an insulation layer under a metal roof to lessen the noise of rain.

Once the roof is on the building can really kick off work can go ahead regardless of the weather can work can be happening inside and out. The Windows and External Door Jambs can be installed at this point so they are ready for the bricklayer.

The next step is to get the termite protection installed and get the bricklayer underway while the plumbing and electrical rough in can be commenced.

To see what happens next go to 'Brick Veneer Platform Floor Section Part 3'

Brick Veneer Platform Floor Section Part 1

This method of construction incorporates a raised platform floor so we need to start with the a Footing system. The system will consist of a Strip Footing running around the perimeter of the building and a grid of Blob Footings through the centre of the building.

The Strip Footing reinforced generally with 2 layers of Trench Mesh, detailed in the plans and specifications. 

While the Blob footing just mass concrete poured into an excavation.

Both the Strip and Blob Footing should be finished level with a rough finish to allow the mortar to adhere to it. They should also finish approximately 1 course of brickwork below the ground so they can be covered up when the landscaping is done.

Next the Dwarf Wall is constructed on top of the Strip Footing. The Dwarf wall is a single skin of brickwork which is built up to the level of the underside of the bearers.

Ventilation is built in to the Dwarf Wall to allow air flow to occur in the sub-floor space. These vents should be placed roughly every metre.

The Dwarf wall is reinforced with Engaged Piers which also act as the bearing point for the Bearers.

On top of the Blob Footing is a Isolated Pier, also known as a Sleeper Pier. The Isolated Pier supports the Bearers through the middle of the building and therefore the spacing of the Isolated Pier is equal to the maximum span of the Bearers and the Joists.

Now we are ready to place our first timber member. Because the brickwork is porous (will adsorb moisture) and we don’t want the timber frame getting wet we need to separate the Brickwork from the timber. This is done using a DPC ( Damp Proof Course) or DPM ( Damp Proof Membrane). Nowadays embossed black polyethylene plastic (Plascousre)  is most commonly used although you can also use products like Alcor and Lead.

Then comes the Termite protection in the form of Ant Capping. A continuous length on the Dwarf Wall, a Half Cap on the Engaged Pier and a Full Cap on the Isolated Pier. These used to be joined together with solder however nowadays there is a special adhesive that can be used. Termite Proof Silicone

Now it is time for our first timber member the Bearer. The Bearer is the lowest timber member in the building. It is set 40mm from the inside of the Dwarf wall centred on the Engaged Pier. The Bearer usually runs along the length of the house. Traditionally the Bearer is not fastened down it relies on the weight of the building to hold them in place however nowadays in high wind areas they can be held down with Builders strap embedded into the Engaged Pier or Threaded Rod cast into the Footing.

The Bearer must be a minimum of 400mm off the ground to within 2m from the Dwarf wall from there is may slope up to a minimum of 150mm  from the underside of the bearer at the wall. This is to allow for good ventilation and good access under the building for inspections.

The Joists are next. They are spaced to suit the flooring that is going to go on top, commonly 450mm centre to centre (c/c) or 600 c/c. They are laid at 90 degrees to the Bearer. Double joists are required under the external load bearing walls where the wall runs parallel to the joists. When you have a platform floor like the one I will show here these joist can sit side by side. See ‘Platform Floor System’ for more information.

With a Platform Floor Sheet Flooring is generally used, ‘Structaflor’ is a common brand. The flooring should be installed in accordance with the manufacturers recommendations. Sheet Flooring is not designed to be exposed to the elements and should be protected is they will be exposed for an extended period.

To see what happens next go to 'Brick Veneer Platform Floor Section Part 2'