question about free standing deck next to house

[Brian Tymchak]

I need to replace a small 3' x 3' deck on the back of our house. So, I'm taking the opportunity to stretch it out a little bit to span across the double-patio door with a little bit extra. In the end it will be 3' wide x 8' long. It's really just a platform to step down a couple steps to our patio. The patio door out to this deck is on a cantilever over the foundation wall, so code does not allow me to attach the deck to the house. I need to build a free-standing deck. Which is good news in that I don't need a permit and I also have pretty much free reign on the design, but bad news in that I have 2 additional piers to install.

I've read a bit about free-standing deck design and I've seen in a couple of write-ups that within 5' of the house foundation, piers need to extend 8' down :eek: because the soil was disturbed when the foundation was dug. I'm not about to dig 4 8' deep holes for piers for a measily 24 sq ft deck. The effort just seems way out of proportion for the result.. Our house is 14 years old. Is that enough time to consider the soil stable enough around the foundation to only put piers down to the frost line? (32" or 38" in our area).

Thanks for any advice,
Brian

[Lee Schierer]

I need to replace a small 3' x 3' deck on the back of our house. So, I'm taking the opportunity to stretch it out a little bit to span across the double-patio door with a little bit extra. In the end it will be 3' wide x 8' long. It's really just a platform to step down a couple steps to our patio. The patio door out to this deck is on a cantilever over the foundation wall, so code does not allow me to attach the deck to the house. I need to build a free-standing deck. Which is good news in that I don't need a permit and I also have pretty much free reign on the design, but bad news in that I have 2 additional piers to install.

I've read a bit about free-standing deck design and I've seen in a couple of write-ups that within 5' of the house foundation, piers need to extend 8' down :eek: because the soil was disturbed when the foundation was dug. I'm not about to dig 4 8' deep holes for piers for a measily 24 sq ft deck. The effort just seems way out of proportion for the result.. Our house is 14 years old. Is that enough time to consider the soil stable enough around the foundation to only put piers down to the frost line? (32" or 38" in our area).

Thanks for any advice,
Brian


Dig a shallower hole and use a "Big Foot" at the bottom of this hole.240363

[ray hampton]

If the temperature of the soil around the piling and under the deck are the same temperature as the rest of your house inside , will the piling depth still need to be below the frost-line ?

[Jim Koepke]

will the piling depth still need to be below the frost-line ?

If you have freezing under the base of the piling, you will have heaving. Unfortunately each piling will heave independently of the other. If they were synchronized, there wouldn't be any worry.

The big foot is a good idea. Also make sure the top of your cement in the post hole isn't "mushroomed" at the top. Water can get under and cause it to lift when the water freezes.

jtk

[Jason Roehl]

Here's what you need (no affiliation, just an example):

http://www.empirepiers.com/

With everything else, you run the risk of the deck sinking in a few years.

[Brian Tymchak]

Thanks for the info guys!

Lee, Jim, thanks for the Bigfoot suggestion. I'm leaning this way now, although I not looking forward to digging 20" wide holes. Too close to the house to get an auger in there, at least for the first set of piers.

Ray, I just assumed that all the ground outside the foundation wall would freeze. The first set of piers will be about 3' from the foundation wall, the 2nd set about 5' from the wall. I know that the ground freezes where the 2nd set of piers will be as the patio just about 18" away heaves every winter.

Jason, thanks for the info on the Empire piers. I've never heard of that product before. Unfortunately, I can't find (via Google) anyone around Columbus that advertises they are a dealer/installer, so that I could call and see if that's a fit (price-wise) for me.

[Jason Steward]

You can always just lay down 4X8 treated and build on top of that, no problem with frost heaving because its not anchored to the house or in the ground. Gives good air flow for the deck. I would use geotextile with gravel on top. We use geotextile we get from the farmers coop that is for around feed lot grain/hay dispensers, Much more durable, and weeds aint getting through it.