First, I'm so pleased to see that this group is still active :-)

Some years ago, I built a small tree house in the woods between 3 trees growing close together. Well, it's more of a platform really (or flet as it was called in those parts, for you real nerds). It is about 6' off the ground and reached via a rope ladder with 2x2" wooden rungs. The ladder is anchored at the ground but is still a little wobbly.

A few years after that, but still several years ago, I had some spare treated lumber and I added the joists for a second level about 8 above the first level. Just recently, after having some deck repair done, I happened to have enough extra deck boards to complete that second level floor.

For now, I have my 6' step ladder out there for access, but I want to build a smaller ladder out of wood to reach the second level. At this height above the ground, I don't want anything wobbly, but I still want it to be fun for the kids (who are much older now) and me (even though I'm older too).

I am envisioning using a couple of 2x4s at a slight angle as the side-rails of the ladder, spaced pretty close together (about 9" between the boards), and then using something for the rungs. That's where I want to solicit your advice. :-)

I don't want to spend a lot of money, I want it to be as easy to make as possible, and I want it to be able to support a full grown man (who may grow some more sideways). Let's say 225 lbs. - that gives me some growing room ;-) The cheapest, would be to just use 2x2s for the rungs, but I feel if I just screwed them in, they would soon fail from my weight. Ideally, I would cut notches for each 2x2, but I don't relish cutting all those notches since the only tool I have to do that right now is a jig saw, and the cuts probably wouldn't be very well done. Then I thought about using some kind of round (like a 1.5" or 1.25" dowel or rail). I could easily cut the right sized hole in the side rails, slide in the round, and use a couple of screws to prevent the round rungs from swiveling. Unfortunately, I can't find such a thing that is pressure treated at the local stores, and I worry that what they have would soon rot and decay outside (though they do have oak at a higher price point, which might last a little longer). They I thought maybe I could use 1" pvc pipe (OD about 1.25") instead of a wooden dowel - it wouldn't rot, but I'm afraid that it would not be strong enough. Finally, maybe just using pressure treated 1x4 (or event some small leftover decking boards that I still have), attached directly with 2 or 3 screws on each end (no notches) would be strong enough - though I'm not sure about the sheer strength of deck screws or if having more of them effectively improves sheer strength of the assembly (are nails better?). Any advice or other ideas appreciated.

Thanks :-)

-J