How to build a Garden Pergola
You will need:
- 4 x Upright Laminated Posts (140mm x 140mm x 3.0m)
- 4 x Joist Beams (48mm x 228mm x 5.1m)
- 16 x Stringer Beams (48mm x 148mm x 6.0m)
- 2 x Clamps
- 16 x Lag Bolts (3inch)
Step 1: Install upright posts
Once you’ve decided on a suitable flat area for your garden pergola, mark your 4 post holes. It’s best to dig with a post-hole digger or two-person auger. Your holes should be 64cm (24in) deep and 23cm (9in) wide. Throw some gravel into your holes to prevent your poles from rotting in wet weather and then place your upright posts into the holes. Use a spirit level to make sure your uprights are level and plumb and then nail in some temporary 2×4 planks to act as braces, holding your uprights in place. Mix some fast-drying cement and pour it into your holes, then leave it to set for 24 hours.
Step 2: Bolt in Joist Beams
Once your pergola posts have set overnight cut your joist beams to span the posts. If you’d like to add some flair, now’s the time – you can cut the ends of your joist beams at an angle or a pattern of your choice. Use clamps to your joist beams in place and drill your holes right through the joist beams and upright posts, then hammer your 3 inch lag bolts into the holes you drilled.
Step 3: Attaching Stringers
Cut the stringers to a length long enough to span and overhang the joist beams. Again, you can cut an angle or a pattern at the end of your stringers for decoration. Plan the even spacing of your stringers and mark this out with a pencil. Use 3 inch galvanised deck screws and toenail your stringers into the joist beams.
Congratulations! Enjoy your new garden pergola.