Hey folks, I'm new to the forum, looking forward to getting involved!
I'm planning a deck over much of my very small (and fairly level) backyard, the vast majority of which is currently concrete patio. The goal is to make the deck as close to grade as possible, basically floating over the patio and lawn. There will be a few spots where I'll need to pour footings in what is currently lawn, but most of the deck will be sitting on poured concrete. Do I need to pour footings where it comes in contact with the concrete as well, or can the deck framing just sit directly on the concrete slab?
It would help if you provided a bit more info about your location, in particular state. What might work in Arizona might not be suitable in Michigan. In addition, how thick is the cement pad? Do you plan to anchor the deck to the pad?
In other words the more details you provide, the more likely others will have a better idea of the issues and be able to offer proper advice that is appropriate to your needs.
Good Luck!
This message has been edited. Last edited by: Simply Me,
Sorry, the deck will be located in St. Louis, Missouri. I'm honestly not sure as I sit here right now just how thick the concrete pad is, but it is at least a few inches. I had planned on anchoring the deck to the concrete.
The deck will be largely free-standing -- even if it is affixed to the side of the house somewhere along the way, that would be more for convenience than for structural support, as there are only a couple of areas where the deck would come into contact with the house. Most of it will butt up against a wood privacy fence, although I don't intend to anchor it to the fence posts, because I didn't put the fence in and I'm not sure how they're anchored.
Since you live in St Louis, Missouri, and since you plan to build a fairly substantial deck which I expect you wish to have for many years. I'd recommend that you might consider not anchoring it to the patio but rather sink appropriate piers into the ground to the proper depth below frost in your area. Then build your deck anchoring it to these piers. Over time frost may cause the patio to break up and having the deck anchored to will create a major task to fix the problem properly. If you only plan to live there a few years short cuts may become someone elses' headache or yours if things change don't go as planned. It is a matter of choice.
A free standing deck will eliminate the chance of water getting in under the siding and rotting out the house. Any concrete pad moves a small amount with frost and rising water tables. Never have the top of a deck even with the bottom of the door. It will allow water to get in under the door and rot out the inside flooring.
joecaption
Posts: 11264 | Location: Halieford VA | Registered: Jan 31, 2004
The house itself is elevated, with about half of the foundation underground, and half exposed -- and the foundation is stacked limestone, per my understanding. With that in mind, the door is actually elevated off of the ground by 3 or four feet and does not come into direct contact with the back door -- we have a small existing deck that is basically a small (large enough for a couple of people to stand on, and that's about it) deck, with some steps that go down to the concrete patio. As I envision it, the deck we're constructing will be at the level of the bottom step, so that instead of stepping down on to the concrete, that last step will be onto the deck. The closer it can hug the ground, the better.
Knowing now that you have an existing deck from the house which you plan to use and add to makes it easier to grasp your plan. However, being close to the ground is not always the best. It limits being able to get under it to deal with problems should they develop. Consider changing your plans and elevating your new deck a foot or 2 to allow you access below it and fewer steps down from the original deck. Also as others have suggested make each deck free standing supporting their load on proper piers and not attaching it to the house to prevent problems.
