DIY plans for dock steps?

[JJMc]

I am looking for plans, would prefer a lightweight plywood frame (1/4") with dimensional lumber treads (or composite). If we can build small boats with 1/4" plywood, steps should be possible...
TIA

[Suijin]

Is this a moveable step for getting from the dock to the boat? Is it something you plan on keeping on the boat when it's not in use? How many steps?

1/4" plywood is not going to have enough strength for the frame at all. If I wanted something to be sturdy and last I'd make it out of at least 1/2", probably 5/8". That would be strong enough for the steps as well if reinforced properly with dimensional lumber.

[JJMc]

Thanks. Yes, portable steps (that I can screw to the dock).
If it's possible to build a 20' sailboat with 1/4" plywood, dock steps should be no problem. I plan to use dimensional lumber for the treads.

[TheOffice]

I'd get precut risers from a home improvement store and go from there.

[Lepke]

The steps need to be strong enough for not only a person, but anything they might carry. I'd be surprised if 1/4" will hold up. My dock steps are made like a stairway. Notched 2x12s. Any wood should be sealed before painting if it's continually in the sun and weather.

[JPA Cate]

Originally Posted by Lepke

The steps need to be strong enough for not only a person, but anything they might carry. I'd be surprised if 1/4" will hold up. My dock steps are made like a stairway. Notched 2x12s. Any wood should be sealed before painting if it's continually in the sun and weather.

Agreed. Think about whoever's the biggest, heaviest that will use the steps, and the weight of batteries. As for attachment to dock, consider through bolting, and sealing the holes with epoxy, then caulking when you install, rather than just screwing down into the wood, moisture will get in and soon rot the timber.

Ann

[jimbunyard]

Don't know how long they'd last, but they'd be plenty strong...pilot holes. glue and a finish will work wonders...

[JJMc]

Jim, it looks like you just drew those. Thanks! I'm going to use 7 1/2" risers and adjust the rest. Much appreciated.

By the way, no paint as it's just an invitation to peeling one day. Thompson's Water Seal and a stain, which is easy to renew.

[Lake-Effect]

I would either bang some steps together using pressure treated deck lumber (2x6, 2x8, risers) -fastest-, or, if the goal was for something lightweight but durable, I would use at least 1/2" plywood in a sort of box-like construction.

I probably wouldn't use Thompsons as the primary finish, but it's better than nothing, as long as you apply annually. If I made the plywood version, I would either use deck Cetol, outdoor urethane, or maybe even a coat of runny epoxy and a couple coats of urethane or spar varnish. All depending on what I've got in stock already.

It's the sort of thing I would doodle up in an old notebook, based on stairs and other things that I've built before. Pretty much like Jim just did.

btw it would get you halfway there to tell us how high, wide, etc you need.

[Jdege]

Originally Posted by JJMc

Thanks. Yes, portable steps (that I can screw to the dock).
If it's possible to build a 20' sailboat with 1/4" plywood, dock steps should be no problem. I plan to use dimensional lumber for the treads.

The panels in a sailboat have curves..

Steps are generally flat.

Curved plywood is stiff, flat plywood is not.

You might be able to get sufficient stiffness out of 1/4" ply by adding a camber to the stairs, but then stepping on them will create significant tension on the stringers, and you'll need something to keep the risers from spreading apart, destroying the camber.

The obvious design for a set of stairs is for a notched stringer on each side with treads between them that are stiff enough on their own, or are backed by dimensional lumber to provide the necessary stiffness.

But suppose you tied your two stringers together with four 2x2s, to hold them in position, backed by rods of allthread, to keep them from spreading apart under load. Then used 1/4 ply as treads, cut a bit long so they had a bit of camber in them when locked into the stringers. The result might be considerably lighter than the traditional.

Alternatively, you could make the treads light and stiff by making them from torsion boxes - two thin pieces of ply separated by spacers, glued together.

[valhalla360]

Big problem with using plywood is it delaminates unless you get high grade marine plywood (very expensive) or you do an excellent job fiber-glassing and sealing it with epoxy (cost and time consuming)

It is possible but not practical structurally. If you have enough evenly spaced supports under each step, it can be done but it won't be much lighter and it will be much more complicated to build.

Since you say it's going to be screwed to the dock, I assume it will stay for the season so weight isn't a big issue. A couple of precut stringers with 2x4's for treads would be about the cheapest option. I've got one with the RV I made that way that's 3yrs old and shows no sign of rot. Probably won't last for decades but it's also cheap and easy to replace any boards that start to rot. If you want it to last forever, get pressure treated wood (the stringers usually already are).

[LeeV]

Originally Posted by jimbunyard

Don't know how long they'd last, but they'd be plenty strong...pilot holes. glue and a finish will work wonders...

Ok, Jim; we need a garage at my house! ;=)

[CaptTom]

Just to complicate things, are you considering storage inside the step unit? It would be a perfect "dock box" for odds and ends you want to keep around, but not on board.

As for the best design, it would all depend on the height and width needed. That would drive the size of material needed for the treads.

One tip: instead of stringers, for 2-3 steps you can just stack progressively shorter 2x8s horizontally on each side, with the treads between them. This is easier than cutting risers, and gives you a solid side wall.

[Cheechako]

If you can keep the 1/4" flat enough it could work for the vertical parts. It's in compression not tension so keeping it "in column" is what you need. But by the time you add a few cleats to make it rigid/flat etc, you are adding weight anyway. If you are screwing it to the dock, why make it lightweight ? I'd use 1/2" or more and make it easy to fabricate.
Then again, at today's lumber prices etc, I'd just buy a set of fiberglass steps. You'll need to finish it with paint or etc too. Exterior ply has the same glue as marine ply, so you dont need marine ply.

[S/V Alchemy]

Originally Posted by JJMc

Thanks. Yes, portable steps (that I can screw to the dock).
If it's possible to build a 20' sailboat with 1/4" plywood, dock steps should be no problem. I plan to use dimensional lumber for the treads.

I guess you weight 40 kilos, then. If not, your premise is faulty. You could build it from lumber and use 1/4" to sheath it, but not as a structural element. If you need it lighter, you could probably build it with countersunk screws into 1/2" over a basic box frame, and then put a series of small hole saw holes in it.