Hello Bunnings
I am researching a project that I am going to undertake shortly. I am wanting to attach a timber pergola to a house. The pergola will be
have width of approx. 5.4m x depth of 2m
a) A H3 ledger board of 190mm x 45mm x 5,4m will be attached to the house with appropriate bolts.
b) Two (or more if required) H4 posts will be concreted into the ground and will have a final height of 2.4m.
c) A main H3 beam will be attached to these two posts (or more), I am thinking 240mm x 45mm x 5.4m.
d) The posts do not necessarily have to be positioned at the ends of the 5.4m main beam. They can be positioned in for some overhang of the main beam.
e) 140mm x 45mm H3 rafters will be attached across the ledger board to the main beam.
f) H3 purlins 70mm x 35mm will be attached across the rafters.
g) A lightweight polycarbonate roofing will be installed.
h). The pergola will have a 5 degree pitch.
It’s a little confusing trying to decipher span tables. For this project I have 3 questions
1. What size posts should I use?
2. How many posts should I use. (I note two above ? need an additional post).
3. Is a 240mm x 45mm x 5.4m main beam suitable for attachment to two posts (or more required).
Hoping you can advise.
Regards John
