Deck Foundation

Old 03-18-09, 03:57 PM
Thread Starter
Join Date: Mar 2009
Posts: 1
Received 0 Votes on 0 Posts
Deck Foundation

Please help.

I am currently designing and planning to build a "yoga inspired" deck at my home. No railing. No stairs. No additional levels.

My home is pretty low to the ground (about 4 inches from the ground to the bottom of a door on one end and about 6 inches on the other). I know cannot and should not just place the deck frame on the ground, but adding posts and beams underneath the joists seems impossible without digging a huge hole in my back yard.

Is there a tried and true method any of you have used for building an extremely low deck? I'm comfortable with every other aspect of building this deck except for the most important part. The foundation.

Taking any and all advice.
Old 03-24-09, 06:54 AM
awesomedell's Avatar
Join Date: Mar 2003
Location: USA
Posts: 2,425
Received 0 Votes on 0 Posts
From what I understand from your post it sounds like you house is just sitting on a slab foundation. Assuming that is the case, I would say you have two choices, either one is going to require some degree of digging. And you didn't specify how large this new deck is to be so this is going to be very general advice here.

A: You could dig some holes at necessary spacing and set some 4"x4" posts, which since they will not need to be very tall you could potentially get multiple lengths of post from 8 footers or 12s. You'd want them set a min of say 36" in the ground depending on the frost level in your area.

B: This would probably be my preferred method, is I would go out there and do a bit of excavating and lay yourself a concrete patio that the finish level is sufficient to allow for a 2"x6" frame to sit on it & then set your deck boards on that. Make sure the slab is approriately sloped to insure water runs away from the house.

Hope that helps and post back if you have additional questions.
Old 03-25-09, 05:22 PM
Join Date: Mar 2000
Location: Arlington, WA
Posts: 9,238
Received 1 Vote on 1 Post

Like awesomedell, I'm assuming that your house is sitting on a slab, given the heights from grade to the thresholds that you are dealing with. Some places just aren't good for installing decks, and your's seems to be one of them. My suggestion is to pour a concrete patio and be done with it. (THAT came from a contractor who installs decks!!)

Where I'm at, a concrete slab costs about 1/3 of what a deck does. To do what you are thinking about will mean that you are pouring the slab, AND THEN adding the cost of the deck on top of it. Granted, no posts, no footings, and very little framing, but that deck surface is STILL going to cost more than the slab itself.

Thread Tools
Search this Thread
Ask a Question
Question Title: