By using steel and concrete you can increase you post spacing to extreme lengths.
This whole is 3'x3 (36"x36") and takes 3 guys about an hour to dig one hole. (picture below)
After the digging is complete the city will inspected the whole for compliance with specifications on permit. Then the concrete pour will be order and the steel posts set. (picture below)
Once the steel has been set the concrete patio slab can be poured around the posts. Below is the finished product of the Alumawood build.
A patio this size would need aluminum posts every 6 to 8 feet but with the steel and footing the post spacing was able to span 20 feet. This took a a patio that would need 7-8 posts and made it possible with only 3.
This post is to show what is possible. The one thing to remember is that this make the job much more labor intensive and costs more in material. On this patio it was several thousands more to have the steel framing done. It is great but in the end you get what you pay for... hope this was helpful.
