Wednesday, November 06, 2013

Glorified Ladder

Recently, I had the opportunity to take on a fairly straight forward but fun design and woodworking project. A couple of friends had some open space overhead in one of their bedrooms with a vaulted ceiling. The space is small but works well for storage. The problem was that there was no means of access, other than pulling yourself up there on the supporting beams. Not ideal in any way.

The room was also too small, as was the overhead space, to warrant a full staircase. The idea was naturally to put a ladder in. There was already an angled wall in the bedroom that logically lead up to the space. This wall was the back side of the cellar stairway, which was in the front hallway.

I took a look at the space and thought that a fixed ladder would do the trick and could also be removed if necessary. There were space limitations both in width, where my friends though that they may want to add some shelving along the bordering wall, and also in depth as we needed to clear the nearby doorway. I took some measurements and then started to think about designs.

What I came up with was a glorified 10' long by 2' wide ladder made from 2x8" fir. The stair treads would be 2x8" and would be inset 1/4" into the rails, also made of the same 2x8" fir. The pitch of the angled wall that the ladder would mount against, the back wall of the basement staircase, was steep. It was 55 degrees in fact. That put it right in the danger zone of too steep for stairs but not quite steep enough for a ladder. The difference between the two that we care about is in how you climb or more, descend. Stairs you walk up and then walk down, both facing in the direction that you are moving. A ladder however, you climb up with all fours and descend the same way, simply in reverse. The plan was to be able to very carefully descend these like traditional stairs, which was why I opted for the 2x8" vs. 2x6". Either would have supported the load of a single person just fine, especially given that the unit mounted against a wall so didn't really support much of any load.

In terms of construction, this was a job that made lots of sawdust and wood-chips. All of the wood had to be milled to give it finish quality and get it to common dimensions. That meant thickness planing all of it. Two garbage barrels of wood shavings later they were set. Then I rounded all of the edges off with the router, making loads more chips. Next I laid the spacing out on the rails for each of the steps and then went to work on designing and building a jig that would allow me to mill the recesses in the rails for the ends of the steps. By insetting them slightly the overlap would carry the load, reducing the strain on the hardware used to physically secure the steps to the rails. I planned to use a pair of countersunk 3.5" deck screws on each side of each step mounted through the outside of the rail along with wood glue on the joint. I chose 1/4" depth as I didn't want to remove too much material from the rails, weakening them. The jig worked fine and I cut the recesses with my router and a 1/2" straight bit set at 1/4" depth. Lots more wood chips though.

The hardest part was actually lining it all up and putting it together, which eventually required some help from Cathy. Finally though I got it together and ready to go. My idea for mounting the unit was to have the ladder a bit longer than the wall that it leaned against such that it stuck up above the floor of the storage space. This would allow me to put some hardware in place to affix the ladder in a free floating fashion at the top. It could also have a quick and easy means of disconnecting it in case you wanted to pull it out.

The hardware design I came up with centered around 3' length of 3/4" black steel pipe/nipple (which means it was threaded on both ends). My plan was to lag bolt pieces of 1.5" angle iron to the floor and have them cantilever out to the outside center of the ladder. I drilled holes in the angle iron beforehand through which I could run the pipe. With the ladder in place, I lined it all up and bored the holes in the ladder rail through which the pipe would run. I put it all together and then lag bolted the angle iron to the floor with a pair of 5/16" lag bolts. I finished it off by screwing end caps onto each end of the nipple, which would keep the pipe in place but could be easily removed. The ladder was able to free float against the wall and also had about 9" of left/right movement if you so desired to reposition it.

The last thing I added was a railing. This was a simple unit made from more 3/4" black steel pipe and fittings. In this case it consisted of two 16" nipples, one 5' nipple, four 90 degree elbows, two close nipples and two closet flanges. I then screwed the railing to the outside rail and that completed the project.

In the end, the pitch wasn't as bad as I was afraid it might be. In fact, the basement staircase we have at our place in Maine is way worse. You certainly want to pay attention but you can comfortably descend them like normal stairs. Success. More importantly, Ben and Rebecca liked them, which is the best part of doing projects like this.

1 comment:

Michele said...