Treehouses?

[jyl]

This winter I want to build a treehouse for the kids.

Any experience, advice, tips, inspirational pics, resources, etc?

I am particulary wondering about what luck I might have in avoiding interaction with the authorities. The location selected is in some evergreens at the edge of our property, which is a ivy slope overlooking the sidewalk and road. The treehouse will be nestled in among the overhanging trees and ivy, closest point about 7-8' from the property line (sidewalk). The platform will be about 6' above nearest ground level, and about 12' above sidewalk level. I'll get the platform up, put up some temporary railings, paint it all dull brown to blend in, and get some ivy started up on it. Then think about adding a playhouse on the platform later. It won't pass code for a "deck" or a "house" or any other structure I've looked up in the Portland City regs. Partly due to the minimum setback being 10'.

[Tobra]

try popular mechanics or some diy website for plans. As a kid I learned you don't want to use nails if the ladder to get up is secured to tree trunk. I like rope ladders and trap doors. Can make one with rope and 2x4 cut to appropriate length. Don't have platform attached to more than one tree if they are smaller, which would seem obvious to me, but...

hope you like working in the rain, pitch the roof if you have one(which I would recommend, tar paper or cheapo composition shingles on plywood deck. extend roofat least 12-18 inches past walls. Try painting the sides camo of the appropriate shades, break up outline(chunks of sponge work good for this). Paint all sides that would be visible. Stand on ground and look up to get idea for pattern on bottom and where roof sticks out on sides. A deer blind might fit your purposes, may find plans for one of those on some hunter/fisher site

[Hugh R]

I built this one for my kids about twn years ago. I used steel studs and put a rolled asphalt roof on it. It's 8x12 feet with a deck. Its ship lap lumber and matches the house. The floor of the house "floats" in that it sits on pieced of wood screwed into the tree, so that it stays level. I bought a book (don't know where it is) at a bookstore that gave me some good ideas. Make it tall enough that you can stand in it.

[911boost]

+1 on buying a book. As a kid my dad and I built one, even had cedar siding. It was the type built around a very large tree (think hole in the center with the tree running up it). It had a trap door and rope ladder. Secure the rope ladder the ground and tree house, makes it easier to climb up.

[M.D. Holloway]

Hugh - great job! Wish I had that when I was young. Would serve as a great fort. And as a teen, as a great great spot to get stoned and laid! And as an adult, a great place to hide from the Wife!

Wish we had a tree...

[Hugh R]

[QUOTE=LubeMaster77;3570078]Hugh - great job! Wish I had that when I was young. Would serve as a great fort. And as a teen, as a great great spot to get stoned and laid! And as an adult, a great place to hide from the Wife!
QUOTE]


Lube, its been used for all three purposes!

Wish we had a tree...


This is about 5% of my back yard in the suburbs of Los Angeles.

[Tobra]

You can build it on stilts, have known several people who have done this. One was basically a two story storage shed, 1st floor was for lawnmowers and stuff, 2nd was for kids. My brother-in-law just built one for his kid, don't know how much six big posts like that go for. My uncle made an A-frame elevated fort like that for his kids. Got four telephone poles and a friend with a crane to set up the frame, built fort on that frame.

[jyl]

I do have a book, very useful. One thing I'm confused/uncertain about is anchoring into the trees.

I gather I should drill and screw a big (3/4" to 1" diam) lag bolt 6" to 8" into the tree, then secure the joist in a way that allows for trunk growth and tree movement, with the load perpendicular to the bolt shaft. I am also under the impression that you want as few holes in the tree as possible, my tentative design will use just one bolt per tree, using two trees about 8 feet apart. Is that all there is to it? Or is there some other trick/tip needed to avoid damage to the tree?

Will support one end of the platform with the trees, the other end w/ 4" x 4" posts set in concrete.

Hugh, what is the dimension of your joists? 2" x 6"? Adequate, or would you use 2" x 8"?

I think I need to overbuild this so that if I do attract the attention of the authorities, at least they won't be able to call the structure unsound.

Guess I need to look at some spanning tables.

[911Rob]

Originally Posted by jyl

This winter I want to build a treehouse for the kids.

One of my few unrealized dreams!

I'd always wanted to build my kids a tree fort and never did.

[Tobra]

If one side is secured to a post and the other to a tree, it will not be long before it is tilting toward the post as the tree grows.

[jyl]

Yeah, my kids are getting older - 11 and 8 y/o - and I really need to do these things before they outgrow the pleasures of a tree fort (and camping trips, and traveling to other countries w/ mom and dad, etc.) And when they do get older, if they turn the fort into a hangout with their friends, well I'd rather have them hanging out in my trees, even if doing something I might not quite approve of, than doing those things on some street corner. So the treehouse is going to be built to accomodate "big kids" . . .

[Hugh R]

I think I used 2"x 6" in retrospect I'd have gone larger, but its at most a six foot span. It hasn't sagged in ten years. Bolt into the tree through a piece of short 2" x 4" with the frame of the tree house bolted to the top of the short 2 x 4. Another thing you could do is use four posts and build around the tree and not attach to it.

[jyl]

Can I get a check from you engineer types?

I am supporting two corners of the treehouse platform with lag screws into separate trees, and two corners with posts set in concrete.

The largest lag screw I can find is 1/2" diameter, ungraded.

My math is that the cross-section area of the unthreaded part of the lag screw (where the load will be) is 3.1416 x ( 0.25 in ^2 )= 0.196 sq in. I read that low-alloy steel has a shear strength of 45,000-50,000 lbs/sq in. Since these are ungraded zinc-plated steel screws from Home Depot, I assume shear strength only 30,000 lbs/sq in. I get that each screw should support, in shear, appx 8,800 lbs.

The maximum weight on the platform (including the platform, house, and as many adults as will be able to fit in the house, will be about 4,400 lbs.

So I am thinking 1/2" diam lag screw will be enough metal.

The screw will penetrate 6" into the tree trunk. The load will be perpendicular to the screw shank. I will add a second, similar lag screw about 6 feet higher on the trunk and run a steel cable to the platform, as a back-up support. I don't know how to calculate the holding power of a screw in wood, so am just "assuming" it will not pull out.

Critiques, corrections, warnings? Thanks.

[David McLaughlin]

This summer, I picked up a book at The Home Depot about just this subject. It's put out by Black and Decker. They go through most of the worries and talk about attaching to the tree, building on stilts, etc. They even have several plans.

http://search.barnesandnoble.com/booksearch/isbninquiry.asp?ISBN=9781589232877

[Nostril Cheese]

Originally Posted by jyl

Can I get a check from you engineer types?

I am supporting two corners of the treehouse platform with lag screws into separate trees, and two corners with posts set in concrete.

The largest lag screw I can find is 1/2" diameter, ungraded.

My math is that the cross-section area of the unthreaded part of the lag screw (where the load will be) is 3.1416 x ( 0.25 in ^2 )= 0.196 sq in. I read that low-alloy steel has a shear strength of 45,000-50,000 lbs/sq in. Since these are ungraded zinc-plated steel screws from Home Depot, I assume shear strength only 30,000 lbs/sq in. I get that each screw should support, in shear, appx 8,800 lbs.

The maximum weight on the platform (including the platform, house, and as many adults as will be able to fit in the house, will be about 4,400 lbs.

So I am thinking 1/2" diam lag screw will be enough metal.

The screw will penetrate 6" into the tree trunk. The load will be perpendicular to the screw shank. I will add a second, similar lag screw about 6 feet higher on the trunk and run a steel cable to the platform, as a back-up support. I don't know how to calculate the holding power of a screw in wood, so am just "assuming" it will not pull out.

Critiques, corrections, warnings? Thanks.

dude, it's a treehouse. Just a couple of boards and nails.

How are you going to get 4,400lbs up into a treehouse?

1/2" lags will be more than adequate. Almost overkill. I'd be more worried about splitting the tree with that size.

[sammyg2]

I built this one years ago.





no wait, now that I think about it someone else built it

[jyl]

Originally Posted by Nostril Cheese

dude, it's a treehouse. Just a couple of boards and nails.

How are you going to get 4,400lbs up into a treehouse?

1/2" lags will be more than adequate. Almost overkill. I'd be more worried about splitting the tree with that size.

True - though I might have to defend it to a building inspector if I am unlucky.

[bivenator]

A building inspector for a treehouse. Over regulation at its finest.
Being that close to the street would afford a good lookout for future kid shenanigans. Wish I had a treehouse.

[jyl]

Originally Posted by bivenator

A building inspector for a treehouse. Over regulation at its finest.
Being that close to the street would afford a good lookout for future kid shenanigans. Wish I had a treehouse.

I totally agree w/ the over-regulation thing. Still, given the location of the treehouse platform vs the sidewalk, I can see someone giving me a hard time on grounds of safety to pedestrians. So I'm overbuilding the heck out of it - main support beams are 2x12s, etc - so that no-one can reasonably say it is at risk of falling into the sidewalk.

[Nostril Cheese]

why not use steel?