Best way to add 'posts' to my existing deck to put a pergola on top?

I have an eight foot wide by 24 foot long deck off the back of the house with a simply three foot rail. The 6 x 6 inch posts that go in the ground are also the base for the rail.... however, now I would love to add a pergola top to the deck. Whats the best way to attach 5 foot posts to add the height to the existing posts? Can it be done without tearing out all the old ones that are 3 feet in the ground and concreted? I don't want to rebuild the deck

  1 answer
  • Jlnatty Jlnatty on Feb 23, 2018
    You're right. The problem is whether the existing footings for the existing posts would be adequate to support the additional weight of added post length plus the weight load of the pergola framing and "roof." An additional issue is whether the underdecking (deck framing) would be strong enough to carry that additional weight load as well. I would guess - no, they're not. Do you know any structural engineers who will give you free advice? If not, I would ask around and hire one to scope out whether your project is feasible and what you might be able to do short of tearing everything out and starting all over again to get a deck with a pergola on top. Good luck, Bill.