Any advice on this little deck extension?

Hey guys, newbie here. Just found this site and there seems to be a wealth of info here, so I thought you guys could point me in the right direction. We have a deck and a patio in our backyard separated by a 12'x20' space of mud thanks to my 2 boxers. The deck has 3 steps that lead to said muddy area, and I was thinking it would be nice if I could take the bottom step, and turn that into a second level of the deck and run it into the edge of the patio. The problem is, this level would be about 2 inches off the ground. I thought maybe I could dig down a few inches, but that didn't really seem correct. I did some research and understand the basics of how a deck is framed, but I couldn't find anything that covers a deck so close to the ground. Does anyone have any info on how something like this could be accomplished? I took a few pics hoping it would help explain what I'm trying to describe.

Hmm, code doesn't seem to be working for me, pics can be found here...
http://s141.photobucket.com/albums/r59/Topshelf147/Deck/

Thanks in advance

 

Topshelf,

Welcome to DoItYourself.com and the Deck forum.

I couldn't get the photos to come up, but that's not a problem.

Don't use the lowest step as the level for the deck extension, UNLESS there's a good reason to. Build the extension at the same level as the existing, or one step down. You'll need space below the deck to get the girder in and the joists on top of that. Then add steps to the concrete slab.

 

The minimumdistance from grade to the top of a deck would be 6 3/4". This would be 2x6 joists and 1 1/4" decking. You would need several grade beams and have very little room for grading to avoid ponding below the deck. Why not continue that beautiful paver patio until it meets the deck?

 

Thanks guys. I would prefer that the new section be level or slightly below the patio. I really wouldn't want to have to step up to the new section from the patio. It's really an unused section of the yard that I plan on dropping a free standing screen room for this summer. I spent some more time looking around tonight and found the key word "ground level deck" which seems to be what I'm looking for, so I had an idea. Hopefully you can tell me if it's a good one. lol I was thinking about removing the three steps that come off of the deck, then installing a ground level deck that butts up to both the patio and the existing deck. I have to measure the patio height tomorrow, but I think it's around 7-8", which would work out with what I saw on the net and what Rockpro says about the 6 3/4" deck height. Once that is complete, I could then frame out some simple steps between the two levels of the deck. Only concern is that without putting a level down yet, it appears that the patio has a slight grade away from the house (which makes sense), while the deck appears level. So I would end up with a larger gap between the deck and patio towards the house. Not sure if that's a major concern.

Also, it's not a paver patio. It's a poured slab with a paver edging. I thought about going with a paver setup in that space instead of the deck as I could tie it in with the look, but I was hoping to do this myself, and as somewhat of a perfectionist, it would take me months to complete the pavers. Plus I would have 2 insane dogs running through the area while I was working on it. And lastly it seems there's quite a bit of maintenance with those pavers as the ones in the front of the house always seem to have weeds growing through them somewhere.

Any thoughts on the ground level deck idea?

 

It seems as if you have two choices. Either match the slope of the patio and make it up on the steps to the deck or keep the deck level and have a small height differential at the patio. Judging by the pics, the slope appears very slight and I would match the slope of the patio.

You will have to check with you local codes regarding footings and spans for the floor joists.

the basic idea is to pour a concrete beam flush with the grade. It will have three or four columns excavated under it the the required depth and rebar in the columns tying them to the beam. Anchor bolts attach a 2x4 on the flat to the beam. This will keep all wood members above grade and the lowest possible profile on which to build

 

The quickest, easiest, least expensive, and longest lasting solution would be to extend the concrete patio over to the existing deck. (You are hearing that from a deck contractor!) Gound level decks are doable, but the wood is going to rot. Concrete won't rot.

Assuming that your patio was installed properly, yes, it slopes slightly away from the house. Not much -- an inch every 8' to 10', so the water will drain off of it.

If you really want to deck the area, excavate the dirt out of it so that you have enough clearance from the bottom of the deck boards to the dirt for your joists, your girders, and some short posts so that you can level the deck framing.

 

Sorry, but I must disagree with the excavation idea. You are constructing a pond under the deck as there is no way for rain water to run off. You will end up with insects galore. Mosquitos, in particular, will just love it.

 

In addition to the excavating, you would have to install a drainage system so that you aren't creating the pond under the deck.

Regardless of how much dirt is removed or how much is left, Topshelf is going to have to install some sort of drainage system if he chooses to deck that area rather than concrete it.

Cost difference -- if I were bidding the 3 options --

A concrete slab would be about $6/sq.ft., a deck at or one step down fron the existing would be about $18 to $19/sq.ft., and at the level of the existing patio a deck would be about $40/sq.ft.

 

First off, thanks so much for all the responses. I really appreciate the help.

Secondly, WOW!!! This is way more complicated than I thought it was going to be. It's been raining hard here all night and morning and it does appear some sort of drainage would be a good idea for that area as there is quite a bit of water puddling up at the moment. But I have to admit I'm a little surprised at the complexity of this building project. If I install some drainage, is there a reason I couldn't just get away with doing something like this?

http://www.diyfinds.com/building_a_ground_level_deck.html

It seems pretty basic and appears to be a sound way of building such a low level deck. Basically instead of using posts, they just mount the beams into the brackets and frame from there. I'm not trying to argue with you guys as I came here looking for advice, I'm just a bit curious as to why I would need to pour concrete beams. It does make sense that it would create the lowest height for me as I think it through though. The excavating idea is what someone told me, but after seeing the water puddle up, I'm not really liking that idea at all.

I honestly thought this was just going to be a simple little deck extension. I should have know better. lol

 

The illustrated method would work for you if your local codes permit it. Check for required depth of footings. The double 2x6 girders that were used appear to have a free span of about 8'. That seems too far in my mind considering the loading but I haven't checked my span charts. Your local building department can supply you with the information regarding spans.


The concept behind the concrete beam is that you don't need to construct a wooden girder. The joists bear directly on the beam. It is also easier to mount the joists this way instead of working with joist hangers at grade level.
Of course, there is a little more work involved in pouring the beam instead of just the footings but it really isn't that much more.

As for drainage, if you already have standing water at this spot, it needs to be dealt with before building the deck. You probably can't raise the grade near the house too much so you will have to lower the grade at the far end or put in some type of catchment system that will permit gravity to drain the area.You only have to get the water out from under the deck. Where it goes after that is another matter.

 

Thanks Rockpro. You wouldn't happen to know where I can see a pic of one of these poured concrete beam setups, would you? I'm trying to get an idea of how it would work and a photo would make it a lot easier. I tried a google search, but I keep coming up with bridge beams. I used the deck builder on Lowe's site and it had me digging 21 footings for what I'm thinking about doing. All 4 corners will be cut at 45 degree angles to match the existing design which seemed to add a few extra footings. So maybe that beam idea isn't really much more work. I'm assuming I wouldn't be doing the concrete for the beams myself as it sounds like it's going to be a lot of concrete to pour. I haven't even started researching drainage options yet, but I get the feeling this is going to be more than I was expecting as well. haha