Lag screws or thru bolt?

Good afternoon, Laby. It is decorative, in the sense it'll never pump water. I anticipate the owner will want the propeller to rotate tho, and because of that, he'll have to climb the ladder on occasion to adjust, maintain, etc., the bearings, blades, etc. Plus, it'll be located in a rather tourist area, and you never can tell about them. Lastly, dumb or drunk teenagers can't be ruled out. Therefore, I need the ladder to be as safe as possible. Thx.

Good afternoon, techno. You make a very good point; I definitely will not be using lag screws. Since there're 31 rung rods, the threading of both ends might represent a significant labor expense. I like your idea of 1" washers if I stay with wood rails.

The ladder will be on ~6º slope from vertical. If the rail width gets wider by 1" for every 1 ft of vertical, the bottom rung would be 48" wide, while the very top one would be 14" wide. This seems like a logical requirement for a portable ladder, but not for a fixed ladder. Hopefully, this will not be a problem.

I'm going to have to check with the local building official about the safety cage. I'm hoping the requirement stems from the occupational safety code, which might not apply to a ladder that is not used in an occupation. Thx.

If the ladder will not be used for climbing, but only be decorative, lag bolts are OK. A lag bolt driven into the end grain of the rungs is a very weak connection. Ditto for nails. Look at the construction of a wooden step ladder. The rungs are dadoed into the rails and a long rod, threaded at both ends holds everything together. At 34 ft, I would seriously consider using steel tubing for the ladder, especially if it has to support a person's weight.

Good afternoon, ronseto. I think you're right. I'm going to change the design to welded steel tubing. Thx.

If it looks like a ladder, and acts like a ladder, it IS a ladder.

If you want something that looks like a wooden ladder, use a wooden ladder.

Alaco Ladder Company in Chino (San Bernardino County), the only U.S. outfit that still sells them.
The San Francisco Fire dept builds it's own custom wooden ladders. ALL other fire departments that use wooden ladders buy them from Alaco Ladder Co. There is no better ladder available to you. If you do not want that expense, consider removing the lowest eight feet of ladder, so it can not be climbed. I hope this gives you some additional options to work with.

Good morning, bob c. Thx for your thoughtful insite. I will definitely include the Alaco Ladder Co. as an option; and remove the bottom 8' to discourage or prevent unintended climbers.

If it looks like a ladder, and acts like a ladder, it IS a ladder.

Except on naval ships, where if it looks like stairs, it's a ladder.

As a boatbuilder and a carpenter, I would advise never to LAG BOLT anything into wood that will be exposed to weather---wood deteriorates, ever so slowly, yet it does go south---with an all thread connection, or a through bolt connection, you can add, or increase the size of the washers on both sides of the compression joint, and you can also go back and re-tension or compress, whichever, as needed--in hot and cold climates, I often have to go back and loosen or tighten structures or joints so they will remain active--just a thot-- remember also---do your homework on types of fittings (galvanized, stainless, bronze, versus the type of wood being used)---I.E.---no galvanized with redwood---it reacts, and causes staining , and will result in a wood rot/ fastener condition -C-Mac

Good morning C-Mac. Thx for your wise and experienced input. I think if the client wants a custom wooden ladder, I will dado the rungs in, and place a tension rod below them.

I suppose redwood would be the way to go for longevity of the wood, and use stainless steel metal hardware. For this option, I wonder which would be better, SS all-thread, or if rods which a local machine shop threads the ends, which type of SS offer better machining qualities? Would you happen to know?

I have dado'ed solid wood ladders together before, for houses that need a lot of maintenace on the roof, while using old growth, recycled douglas fir, vertical grained---I use a product from a company in Washington, called Dr. Rot(you can Google it up)---it is a 2-part penetrating epoxy, with a viscosity similar to diesel fuel---I wick it into the end grain and let it dry before gluing everything together---I also coat the entire structure with this same epoxy, as it makes a perfect base for other topcoats---The last one we did has lasted 20 years, with no rot. Stainless steel is the way to go-check with ships' chandlery's, unless you have a large metals place near-by to either pick-up or have shipped.---Go to a marine store and get the scoop on types of stainless for your application----Look at the catalog, on-line, for Defender industries, and see what stock is available , off the shelf---custom threading may cost a mint---let us hear----C-mac

Good morning C-Mac. That epoxy coating is certainly something to keep in mind. Thx for the suggestions.

A few more thoughts:

As mentioned above dadoeing is the strongest. It is a little more work to create. To make it easier secure in place a pair of 1 x 4 supports against each rail in between each rung supporting the rung above and resting on the rung below. If the 1x4s are all cut at the same time from a jig they will make for parallel and even rungs without any effort. Secure the rungs with galvanized 3.5 in lag bolts from each side. The machine bolt attachment to the structure will eliminate allmost all of the lateral load on the lag bolts and the blocks will eliminate any vertical load on the lag bolts. This will be the strongest in wood construction, have the lowest maintenance for the longest time and be the least expensive to build.

Steel tubing unless stainless will be a maintenance nightmare after a few years of rust. In order to prevent the rust you will spend all year chipping, scraping, brushing and repainting. To avoid this use stainless steel or aluminum. Tubing is also uncomfortable to stand on for long periods

A 34 ft ladder is a tall ladder. If you have bolted the ladder flush against the structure, then there will be no place to wrap or hook ones fingers around the rails or rungs. This will be a strenuous and tiresome climb holding on by the squeezing of ones fingers which is much more tiring than wrapping or hooking your fingers around rungs and which therefore may be prone to slipping off. This would be exacerbated by needing to stay put on a portion of the ladder to do any required maintenance. It would be silly to have to bring another ladder to maintain this ladder because you couldn't hang on. You can cure this issue by placing 2 x 4 spacers between the rails and the structure where you through bolt the ladder to the structure. This will also solve my next point below.

If the ladder is flush against the structure with a 60 degree slant then you will have to provide drainage as water will collect and sit on the wood increasing the rate of decay.

If you use wood, use pressure treated lumber.

I had not seen your last post and rethinking ornamental:

White oak is a more expensive but more durable alternative to both redwood and treated lumber (prettier as well). White oak is a very oily wood that holds up extremely well to the weather. White oak was used extensively on old wooden ships.

Any kind of screws, even stainless, will corrode and leave an ugly black stain below the screw after a few years. If you want to upscale your ladder; drill, glue and dowell the rungs with white oak dowells.

I would use blocks instead of dadoeing because of the cost savings. Dadoeing is not really a field job, but a custom wood fabricator. Keeping all the rungs parallel and evenly spaced works very well with a 1x4 block, mass produced on a jig and can be easily done with a chop saw in the field and the dowell holes easily drilled with the blocks in palce.

For the through bolts on the rails, countersink and then put in plugs to protect the finish.

Good morning sail4evr. Thx for your post. I realize the savings of your suggestion. With this design, I guess the thru bolt under each rung could be eliminated.

For the custom steel ladder option, I was going to use 3x2x3/16 structural steel tubing welded all around to each rail. After it rusts, it could be mistaken for wood; from a distance. With the rungs installed with the 3" sides horizontal, it would provide a large bearing surface for the climber; and therefore avoid the foot pain a rung of circular cross section would give. But this design would be heavy, and labor ($) intensive for the client.

The rails would be also of the 3x2 tubing, allowing the advantages above, while still providing a reasonable rail one could easily grasp. This is because, while the rails will be bolted flush against the structure, the flushness or interference will only be where the rails pass over a 2x6 cross member, which would be easily reached over by the climber. Additionally, there is no foreseeable reason the climber would need to stop at any place other than the top; for maintenance or adjustment of the windmill works. If need be, the spacers you mention could be incorporated into the final product.

Actually, the slope of the ladder is only 6º from Vertical.

I guess in order of quality, the best wood would be white oak, then redwood, and last pressure treated lumber?

"For the custom steel ladder option, I was going to use 3x2x3/16 structural steel tubing welded all around to each rail."

Why use steel? Aluminum would be lighter and non-rusting. Navy ships use aluminum ladders everywhere, some longer than 34'. Their rails are usually a 3"x1 1/2" channel or rect tube. The rungs are extruded aluminum treads 12" long, bolted or welded to the rails. I know there are companies that make them for the Navy, but I don't have a name handy. I will do a search on the web.

Make sure you provide at least 6" between the ladder rungs and the structure to allow for toe clearance.

The good thing about a metal ladder is, you have something to hook a safety belt unto.

Another possibility for a ladder would be a single wood beam with climbing spikes driven in to opposite sides (telephone pole style).

I'm guessing the 6º slope is to match the slope of the windmills legs?

Good morning ronseto. You make an excellent suggestion. I have Reynold's Aluminum's "Structural Aluminum Design" book, but altho it has square tubing, it has no rectangular tubing. Maybe because the book was printed in 1967. I found the modern equivalent on Amazon, but it doesn't let me look inside to see if it has rectangular tubing. In the meantime, I found on the internet a 1.5 x 3 x 0.125 6063-T5 rectangular tubing, which might be perfect for my application. I need to confirm that 6063-T5 is ok for welding, and what about the welding ruining the temper? Would the fabricator have to send it somewhere for tempering? What about the finish? If it were Alclad, wouldn't the welding ruin the finish, and then corrosion would start?

On the toe clearance, there is only one rung out of the 25, that has no toe clearance. Hopefully, this would be ok.

I wonder if a mandated safety belt would eliminate the cage requirement.

I'm no climber, but if I were, I'd want two rails; rather than the telephone pole style spikes.

Yes, the 6º comes from the slope of the windmill structure.

I would avoid structural steel tubing. It may look like wood as it begins to rust but then it will look like sh_t when it rusts further. No one will want to put their hands on it as the rust is flaking off. At some point it will not be safe to climb and I would think the lifespan is less than white oak or treated lumber.

What I don't like about redwood is that it is a soft wood and walking on the corners or edges will round it off.

White oak is more expensive.

Treated lumber is poisonous and may not be allowed in your area. Life is a compromise.

Even stainless comes in so many grades and the impurities that are left in ss to reduce costs will allow tarnishng and rusting after a year or two unless you know you are getting a grade that does not tarnish. For example I have a 25 year old boat with stainless stanchions. Without maintenance the stainless looks like new. I recently bought stainless rope to replace my lifelines and after 6 months it is starting to rust. Of course a quick pass with metal polish restores it but my older stainless is totally maintenance free.

As ronseto said, the aluminum might be able to solve most of the issues raised so far, by powder coating the ladder in a color to match the wood, or perhaps a contrasting wood color. Powder coating if done correctly is a lifelong finish.

Aluminum is a good option but the welder is going to get you for $1,000 at least just for welding.

A rough carpenter would cost you $200 to do it in wood plus the materials.

That 6" for toes is good. I have no idea what the budget is.

Good morning again sail4evr. Again, you make a good point. I was thinking of designing an aluminum ladder in the event the client doesn't want to use steel. At that time I could advise him of the expected cost, if he weren't already aware of it. Since this ladder would be so high, for safety reasons I have almost eliminated any consideration of using wood. I don't want to hear a lawyer knocking on my door some day.

Good morning bob c. That is a nice considertion, powder coating in a wood-like color. I will include it if I design an aluminum ladder. Thx.

Good morning sail4evr. I anticipate that the owner will only climb this decorative windmill once or twice, to adjust the thing so it won't tear itself up during a strong windstorm; after that, no one will ever climb it again. Therefore, I don't see the hand on the rust as a problem, or the safety thereof. I'm thinking that since this is a dry climate, with no seawater for hundreds of miles, the time it would take to rust it to a non-safe condition would be far beyond his lifetime or the design lifetime of the structure. The relative permanence and rigidity of a steel ladder is appealing. Thx for your note.

Hello flyinghigh,

The steel will last a long time in Ariz. Unless it is by a swimming pool(chlorine etc.).

Don't let it rust but put on a dark brown primer and then a lighter brown paint. While the paint is still wet use a woodgraining tool (looks like a old time blotter) to give it a grain.

But unless you use a good and heavy primer the first Haboob (for those who have never experienced it http://en.wikipedia.org/wiki/Haboob) will take it down to bare metal.

Removing the first 8 ft is a good idea, you could even make a portable section to lock in place that could be stored elsewhere. The government tries to protect their chattel where Darwin should preside so cover your posterior.

Best whishes and take some pictures and post them

Brad

Good morning Brad. That is a good suggestion. I will make it an option for the client. Altho I wasn't aware of the name Haboob, I have experienced a number of those in this area, having lived in Az most of my life.

Yes, I have already removed the ~9' closest to the ground. I think the client will see the obvious need to protect he and I in the event a drunken teenager wants to impress his girlfriend, or some one with suicide tendencies wants to end it all. I will leave it to him to keep a 10' ladder at his maintenance place for the rare occasion he will have to climb the windmill.

If this project ever comes to fruition, I will take pics and post them for all to see.

In Walt Disney World, they have a hotel complex called Port Orleans. It is made to look like an old 1900 era port area. As a focal point there is an old (looking) water wheel, that has an amazing amount of detail, including a drive system that could drive the machines that might have been found in a shipbuilding facility of that period. They even have a partially built ship in the dining room, hung from the ceiling.

Port Orleans. Food, fairly good. Sleeping accommodations, good. Attention to details, and water wheel construction, great.

All of you that like to see old working machines, At least have lunch there.

Good morning Bob. I assume that is in Florida. I will definitely make it a point to visit that restaurant the next time I'm down there. That reminds me of the Thomas Edison museum in Detroit, which I thoroughly enjoyed a few years back.

flying,

If the ladder will only be used rarely or occasionally, why mount a ladder to begin with. A couple of brackets mounted high to secure and stabilize a portable ladder should do it. Not having a mounted ladder also serves to deter unknown persons, like kids (or cats...in pursuit of birds or safety?), from ascending the decorative windmill.

Just a (cheap) thought...

Good morning, CowAnon. You make an excellent point. I will make this option known to the client.

hello;may i ask what it would be used for?would there be alot of movement?even drilling holes first either for leg bolts or threaded bolts,i would use a metal sleeve to help guard against the wood splitting,i hope this helps,

Good morning blackhorse. Thx for your comment. Originally, I was trying to design a ladder for a tall decorative windmill, to be used as a tourist attraction at a nearby town. Because of various suggestions and discussion on this list, I changed to a welded steel ladder. But it looks like all the work I put in on this project was for nothing, because the "client" does not return my phone calls. I guess I should've asked for an earnest money check up front. ;^(

don't worry about wasting anyones time---it is all good fodder, and gives us all a chance to intermingle and throw out ideas----who knows what all this data will used for in the future?---thanks for the "idea"----C-mac

Not a problem, the mind is like a muscle if not exercised it becomes flaccid. Thinking of solutions to issues outside of the daily grind keeps us nimble.

My guess is his funding just got reallocated and he is embarrassed. I used the SWAG factor

Brad