ITC-SA Erection of a gable to gable roof

Part 4 of the ITC-SA Roof Erection Training DVD
Wall plate attachment 0:05
Marking position of trusses on the wall plate 0:31
Positioning 1st truss on wall plate 0:42
Plumbing trusses with a spirit level & temporary bracing(attachment and member size) 1:10
Positioning of truss at gable wall & temporary bracing of the first three erected trusses at the gable wall 1:40
Installing the 1st truss at the other end of the building & temporary bracing of these trusses 2:04
Attachment of string line to the apex of the trusses at each end of the building in order to line up the trusses 2:23
Erection of the intermediate trusses between the two ends of the building at the positions marked on the wall plate & lining up the apexes of the trusses with the string line and skew nailing the heel of the trusses to the wall plate 2:44
Sighting the apex of each truss to see if it is plumb & attachment of battens at the apex of the truss & attachment of runners on the bottom chord to hold the trusses in position 3:06
Lifting trusses in place ( actual site example) 3:30
Straightening the truss chords using a string line and spacer block. 3:44
Levelling of trusses using wedges 4:33
Installation & splicing of permanent rafter bracing 4:59
Temporary attachment of rafter bracing to the wall plate 6:07
Truss checked for plumb and straightness and the attachment of the rafter brace 6:22
Permanent fixing of rafter brace to the wall plate 7:07
Installation of the shelf brace 7:51
Installation of bracing frames 9:17
Attachment of hoop iron & wire ties at the heel of the truss 11:08
Installation of the apex, tiling and plaster batten 11:40
Calculation example to work out batten spacing & marking the batten positions on the top chord of the truss & trimming the overhang 13:08
Splicing of battens & positioning of splices 14:57
Battens cut to length at gable wall 15:17
Attachment of plastic underlay prior to the attachment of battens to the top chord, securing, positioning and lapping of the plastic underlayment 15:27
Using chalk line to mark position of battens on plastic underlayment & the attachment of the battens over the plastic underlayment 16:05
Installing web runners & web cross bracing 16:23
Colour coded bracing illustration 17:21
Web stiffener and T-bracing installation 17:42
Installing bottom chord runners & bottom chord cross bracing 18:33
Installing purlins & procedure for erecting trusses for a sheeted roof 19:39
Calculation example to work out purlin spacing 20:05
Installation of top chord bracing for a sheeted roof 21:00
Installation of bracing frames for a sheeted roof 21:32
Roof inspection sign off sheet & placement of roof tiles 21:45

[@waibiivan837]

Good but how can I know that this house needs this measurement/size of roofing

[@mvuyisenisofunwa1888]

How to attach Rafters to the wall plate?
How to attach wallplate to the wall which fastners to be used?