A second layer of dimensional lumber is always fastened to the top plates of the erected.
Roof wall plate position.
Put the rafters into position and then drill a hole through the top of the rafter in line with the middle of the wall plate see red arrow above.
This marks the plumb cut at the inside of the house wall for the notch called a bird s mouth to seat the rafter one the wall plate.
Definition of roof slope.
Where trussed rafter roofs are not subject to uplift a minimum of two 4 5mm x 100mm galvanized round wire nails skew nailed one on each side of the trussed rafter or truss clips fixed in accordance with the manufacturer s instructions are acceptable.
In order to get the right amount of 2 by 6 lumber to use as your roof joists you will need to measure the top wall plate.
Roof slope is the amount of change in height as a ration of horizontal distance traveled usually expressed as inches of rise per foot of horizontal run or cm of rise per m of horizontal run.
Step 1 measure top wall plate.
Add 2 by 4 lumber to a 2 by 4 stud wall or 2 by 6 lumber for a 2 by 6 stud wall.
Measure and mark the top plate of the walls on either side of your structure running in line with the proposed roof s ridge every 24 inches.
Fixings used to connect the roof structure to the wall plate should be specified according to the roof construction and exposure of the site.
This means that from the center of one joist to the center of another there is 16 inches.
38 x 100mm or in accordance with local practice.
Start from the same end on both walls so that the sets of marks are parallel.
Then knock a 6 nail down through the hole and securely into the wall plate.
The roof joists will need to be spaced at 16 inches on center.
When the measurement is equal the plates are square.
The ceiling joists are attached to the top plate and tie the walls of a structure or a room together and supports the ceiling lining of the structure or room.
Normally a roof span is the same as the building width between the outer edges of the wall top plates.
Also sidespike 4 ovals into either side of the rafter again into the top of the wall plate blue arrow above.
Holding the square in the same position as before mark down to the side of the tongue.
If the new stud is too short it will not support the plate and roof.
Step 2 stand the first truss on the end of the wall flush with the outside end of the wall.
Upper wall plate top plate or ceiling plate upper wall plate which is fastened along the top of the wall studs before the wall is lifted into position and on which the platform of the next story or the ceiling and roof assembly rest and are attached.
Matching the exact length of the studs is vital.
Another way when the roof is too large for that or there are not four corners is to use the 3 4 5 method shown here to make sure the corners are at a perfect 90 degrees.
Use the same type lumber as the rotted studs.
Note the square is turned over.
To provide strength and even spacing a hanging beam is nailed to the top of the ceiling joists not shown.
They should be fixed firmly to the brick or blockwork underneath.
Add the length of the overhang beyond this mark and mark it.
