Ships Ladder

Charlie Spitzack walks us through how to build a Ships Ladder for your Treehouse! Nelson Treehouse and Supply uses Ships Ladders in just about every treehouse they build! We want to teach you how to Do It Yourself!

This is an Intermediate level carpentry project! We suggest you have some basic carpentry knowledge before starting this project.

We like to place our stair treads about 12" apart. This means we are going to have to cut a series of pockets with a router. In order to prep for the router, we rip down both 2" x 12" stringers so they have a clean, 90 degree edge. Next, determine the pitch of your ships ladder. We chose 18 degrees for this example. Then set our stringers out on sawhorses, so they were creating a mirror image of each other. Now you have a clean edge to base all your measurements off of.

Doug fir comes with a factory cut 1/4" round over, you can see here that does not fit in our pocket. Therefore we will use the palm router with 3/8" round over to cut for fit. You will also need to rip down the backside of the 2" x 6" x 12" to the same degree you cut into the bottom of your ships ladder (18 degrees). We put a stop on the chop saw to quickly cut all stair treads to the same length.

Using your speed square and a tape measure, mark out all stair tread locations. Remember, your tread angle is going to be the same angle you cut at the bottom of the 2" x 12" stringer. (18 degrees). It is important to know the location of each tread before you begin to cut your pockets with a router.

The bearing on top of your 3/4" straight bit comes into play here. Remember to set your bit to the right depth, so it doesn't cut entirely through the 2" x 12" stringer. Using a scrap piece of wood, cut a jig to the width and depth of your stair tread. The bearing will run along this jig and cut the same shape every-time. Using clamps will ensure the jig does not shift mid cut. Continue to cut out all the pockets on one side of the ships ladder. Remember, you're going to have to mirror the angle of the jig when cutting pockets on the opposite side.

Using the 1 1/2" forstner bit, cut holes at each end of your railing. Using a worm drive skillsaw, plunge cut between the two holes, and finish with a pull saw. Then repeat for every stretch of railing.

Using the worm drive, pull saw, and jig saw, cut the top design out of the ships ladder.

Using the palm router and 3/8" round over bit with bearing on bottom soften up the edges. You don't want to be grabbing onto any sharp edges! Leave the backside square.

The pull saw sometimes leaves nasty marks that can be quickly chiseled away. Also, take the time to sand EVERYTHING before putting the ships ladder together. Sanding now will save time later.

We will be using 1/4" by 4" lag screws, these need to be pre-drilled. Drill two pilot holes in each pocket.

That feeling of accomplishment will be felt now. Finally it's time to screw the ships ladder together! Apply wood glue to pockets, and screw the 1/4" x 4" lags through the pilot holes and into the stair treads. Put the bottom and top stair tread in first, then just slide all the other treads into place and screw them down.

Set to dry for 24 hours in a warm climate. Don't forget to pat yourself on the back!

Check us out at: Nelson Treehouse and Supply & Be In A Tree
You can also purchase ships ladder plans here!