Truss Roofs Flashcards
How far from the gable wall is the first truss positioned?
50 – 60 mm
What checks should you make on the wall plate before erecting the trusses?
Check for level, parallel, square & firmly fixed.
How are the truss clips attached?
30 – 40mm twist nails.
How are the longitudinal braces lengthened?
Must lap over at least 2 trusses.
How is the wall plate lengthened?
Half-lap joint, length 1 ½ times the width of the timber.
How are the diagonal braces lengthened?
Must lap over at least 2 trusses.
At what angle should the diagonal braces be positioned?
As near to 45 degrees as possible.
What is the purpose of the restraint straps?
Wind protection, to tie the timber to the brickwork.
At what centres are the restraint straps positioned?
Maximum of 2m centres.
How are the restraint straps secured in place?
Fixed to the timber with 30mm twist nails and to the brickwork with screws and plugs.
Why does the roof require ventilating?
To keep the moisture content below 18 percent and prevent rot and corrosion.
State three different styles of eaves finishing?
Flush eaves, open eaves, closed eaves or sprocket eaves
What type of eaves finishing slows down the rainwater on steep pitched roofs?
Sprocket eaves.
What part of the roof is the guttering attached too?
The fascia board.
What is the name of the part of the roof where the gable ladder is attached?
Verge
Where would you find a barge board on a roof?
At the Verge.
Name the roof member where the inclined surfaces meet at an internal corner?
Valley
Name the roof member where the inclined surfaces meet at an external corner?
Hip
How are the restraint straps installed up the gable wall?
fixed at 2m centres supported on a noggin between trusses and angled bend overhanging into the cavity.
When erecting truss roofs what PPE should you be wearing?
Safety boots, hi-vis, hardhat and maybe gloves.
What part of the building regulations covers roof construction?
Part A
What visual safety checks would you carryout on your circular saw before using it to cut the braces to length?
Check the body of tool for damage, check battery connections, check guard operates correctly, check cable for damage.
What health and safety regulations are complying with when installing truss rafter roofs.
HASWA, PUWER, WAHR, PPE reg, Manual handling regs, COSHH
Your nail gun becomes jammed what action should you take?
Remove the battery and gas canister first, then using the appropriate tools release the jam.
