Frost Depth - Foundation for play house

[Erik A]

Now Ive gone and done it!!! I thought it would be cool to build a play house for my great niece (3 years old). I talked about it and printed her a picture (attached). I figured a year or two, maybe sooner to build it, she probably would not even care yet!

Big mistake!!

Every day she tells mom about the house uncle Erik is building her! She sees sheds and pump houses on the way to town, and tells her mom how her house is going to be, today she decided it needs a lock for the door so she can keep people out!

So ... my question is -

What to build this thing on? I intend on a 6X8 foot print for the structure and I could put it on
A. timbers or railroad ties
B. piers - Can you set the piers maybe 4-6" in the ground with no freeze issues?
C. 4x4 treated set in concrete - may not be easy to dig very far, the ground is full of boulders!
C. foundation (maybe a little overkill). and same boulder issue!

It is located in Oregon at 4000' so building code is 24" foundation depth for freeze. I have been away from dealing with freezing for many years. Also, I dont want to make it open underneath, I worry that will just attract critters (they are in rattle snake area! although far and few between)




 

getting rid of some surface rocks


 

[thecfarm]

I built the wife a Women Cave,12X20. I set that on cement blocks and the frost has not bothered it. BUT I do live on a sight hill. Water drains away from me. No help to you, because it's open under it.

[firefighter ontheside]

For something like that I would dig down about a foot and pour some pads.  There's still potential for frost to affect it, but not a lot.  I assume its very sandy there and doesn't hold a lot of water.

[florida]

Don't cast your pearls before swine by which I mean that a 3-year-old will have no appreciation for the large, fancy playhouse you're thinking about. First, she's small so make it small, 4' X 4' is plenty. The roof can be a simple shed and should fit her so keep in about 54" tall on the high side. Kids like things cozy. Build it small and easy and she can be playing in it next weekend. She'll be a teenager by the time you finish your sketch.   I've built lots of these and never had a kid yet that spent much time in one. 2 years from now it'll be a mower shed. For that matter, she'd be just as happy with a refrigerator box.

[Tacotodd]

She's definitely going to outgrow it fairly quickly, so don't make it "to code" unless you just have to, and don't make it rot proof if you don't have to. It's likely just going to be needing to be bulldozed over before to long. By the time that she no longer appreciates it would be long lasting enough. Just something to think about.

[farmfromkansas]

I have been thinking of a play house for my granddaughter, 2 yo, and think I will put 4-4x4's in the ground, and build the thing a couple feet off the ground, and add 2 more 4x4's and build a little deck on the front, maybe 4' wide by the width of the playhouse.  The steps up to the deck should be short, and could add a little slipper slide on the end for her to get down from the porch. Thinking a couple tiny windows, and a walk in door.   Like the idea of getting it off the ground, to keep the snakes and such out.  Mice and rats could still move in if you don't make the door fit tight.