You will need
- A length of wooden board
- A strong bungee cord with metal (not plastic) hooks
- A drill and a wood bit (approx. 3/16" or 5mm)
- Thick foam material and glue (optional)
The board needs to be strong and stiff - an offcut of floorboard is ideal. It should be about 8-10" (20-25cm) wider than your ladder - my board measures 22" x 5" (56cm x 13cm) and my ladder is 14.5" (37cm) wide. The bungee needs to be a little longer than the board when measured unstretched between the curves of the hooks at each end - I used a 24" (61cm) bungee. If in doubt, cut the board long and then shorten it if necessary to suit your bungee.
Step 1: Drilling the Holes
Step 2: Adding Foam (optional)
Step 3: Fitting the Spreader Board
Check that the bungee is tight enough to hold the board firmly, but it shouldn't be stretched so tightly that the board can't "flip" - see next stage. If the bungee seems loose you could try tying a knot (or two) in it. If it is so tight that it was hard to get the second hook into its hole then you may need to saw a bit off the length of the board.
Step 4: The Spreader Board in Use
There is one thing you need to watch out for when lowering an extension ladder with a spreader board fitted to it - always leave at least one rung of the top section clear until you have the ladder on the ground and can remove the board. If you forget and drop the top section fully with the ladder held vertically, in the normal way, there is every chance that the board will be pushed off as it comes into contact with the section below it, and hit you on the head. Guess how I found that out.