Call me frugal, heck even call me cheap. But I would not climb up on that ladder until spending several hours contemplating my set up. I first asked myself if the ladder/scaffold collapsed or if I fell off it, would it hurt as much or more than the huge kidney stone that I suffered? See picture posted earlier in this same thread. Would the incident be more potentially lethal than the 9mm piece of calcium oxalate? The answers were "Yes" to both questions, hence I took every precaution.
Following were the potential dangers.
1) The ladder collapsing.
2) The scaffold collapsing.
3) The top of the ladder sliding sideways on the wall.
4) The ladder falling backwards.
5) The ladder feet sliding off the scaffold platform.
6) The ladder feet pushing on the scaffold causing it to slide away from the wall.
7) The ladder feet pushing on the scaffold causing it to tip and fall away from the wall.
8) I fell off the ladder.
Now let's consider each peril.
1) The ladder collapsing.
My 20-ft aluminum extension ladder was in good shape with no corrosion, no weakness. It is rated for 225 lbs, quite a bit more than my weight. Check.
By the way, one of my friends who was on the obese side at 250lbs broke a rung of his rotted wooden ladder. Thank goodness it was only a short ladder he used to hang Xmas lights on the roof overhang of his single-story house, and he only hobbled for a week or two.
2) The scaffold collapsing.
This was the first time I rented a scaffold. I didn't know its weight rating, but this was a professional grade the same as home builders used. The blue end sections are 1-5/8" steel tubes.
Its weakest component would be the horizontal aluminum platform, but it was far sturdier than the ladder, being rated for two workers standing on one plank (500lbs load).
3) The top of the ladder sliding horizontally (sideways) on the wall.
This was a real danger in this situation. My lot is on a high point with a commanding view of the surround, and subject to a lot of strong winds. Though I would not work on a windy day, a sudden wind gust could easily blow me and the ladder skidding sideways. This was prevented by two long ropes tied to the top of the ladder with the other ends of the ropes secured to the deck railings on opposite sides of the deck. Picture the ropes as forming an inverted V with the apex 25 ft high and the base about 100 ft apart, and the ladder at the center of this inverted V. The ropes were rated at 100 lbs, and this should be sufficient.
4) The ladder falling backwards.
This is seen most often in commercials showing a guy clutching the ladder as both fall backwards away from the wall. I seriously doubt that many real-life accidents were like this. If one sets up the ladder too close to the wall, one will not feel safe at all the moment he climbs up. The angle must be enough so that one can lean forward towards the ladder to prevent falling backwards if neither of his hands could grab the ladder. Too much leaning would cause the next danger however, when the ladder feet skid away from the wall.
5) The ladder feet sliding off the scaffold platform.
The ladder feet sliding away from the wall is the most frequently occuring accident. This is not at all surprising, as it is easy to over-lean the ladder in order to feel safe from falling backwards.
One can spend the time to read the following analysis involving friction coefficients between the ladder feet and its supporting base:
http://www.triodyne.com/SAFETY~1/SB_V12N1.pdf.
Or one can just obey this following OSHA and industrial practice. The ladder feet should be placed 1 ft from the wall for each 4 ft of height, or each 4 ft of ladder length. If you want to split hair, the first condition means the ladder is 14 deg off vertical, and the second means 14.5 deg.
In my case, I took no chances and built a wooden base with a slot for the ladder feet to sit into. The ladder feet and its base were then STRAPPED to the scaffold platform supporting the ladder. A 500-lb strap was employed. This is way overkill considering the required force that is described next. Check.
Another significant reason to not have the ladder feet resting on the scaffold plank was that I did not trust the plank laminated wood deck. The rental units were old and the wood got soft. I wanted to transfer the ladder load to the two plank aluminum side rails with the ladder base. Note that this arrangement does not show up well in the photo.
6) The ladder feet pushing on the scaffold causing it to slide away from the wall.
Ignoring the weight of the ladder at the moment, and just think of a 200-lb person on top of the ladder (my weight is less than that). What is the sliding force at the ladder feet? At the recommended leaning angle of 14 deg, application of "sum of forces and sum of moments being zero" principles yields a sliding force of 50 lbs. Can this cause the scaffold to skid?
The 2-level scaffold altogether weighted 400 lbs (4 planks, 4 end sections, 4 cross braces). Add to that our ladder load of 200 lbs. I didn't know the friction coefficient between the open-ended frame tubes and my deck, but I knew that the scaffold tubular feet left O-shaped indentations on the wood deck. There was no way a 50-lbs force could drag this entire 600-lb structure across the deck.
And by the way, I wonder if any idiot would put caster wheels on the scaffold feet in an application like this. Heh, heh, heh...
7) The scaffold tipping backwards from the wall.
Is this is the scenario imagined by Calmloki, or is it case 6? Heh, heh, heh... As I said, I envisioned all these scary scenarios myself to make sure they wouldn't happen. Heh, heh, heh...
Can the above side force of 50lbs applied at the top of the scaffold cause it to tip over? Let's see.
The height-to-width profile of the scaffold is 2 to 1. The ensemble center of mass couldn't be too far from its geometric center, so that the lever arm ratio of the tipping force to scaffold weight is now 4 to 1. The force ratio is 50 lbs to 400 lbs or 1 to 8. So, no tip over. Check.
But, but, but, to be sure, I used 2 ropes to tie the mid-point of the ladder to the chimney. Pretensioning of the ropes took away much of the aforementioned 50-lb skid force, thus helping all items 4, 5, 6 and 7. More than that, another significant effect of the mid ropes was to apply a mild tension to the ladder, keeping it from feeling "bouncy". Though the ladder rating was quite adequate given manufacturer's liabilities and all that, a long extension ladder always bounces. This has extreme psychological effects, let me tell ya. That brings us to the last point.
8) Me falling off the ladder.
Despite all the precautions, there was a lot of apprehension when I was on that ladder. Throughout the entire "experiment", the whole structure was solid.
The shakiness of the ladder was due to my "PIO" (Pilot Induced Oscillations) more than anything else. I was afraid I might get a heart attack and fell off. What if I slipped or lost grip of the ladder, despite always hugging the ladder with one arm while the other hand was holding the brush? So, I had a safety belt that I clipped onto a ladder rung at waist height when I reached the working height.
I was fully convinced that the whole structure was quite study and safe. I also took extreme precaution. The photo was made of only one setup. The chimney was wide enough that my arm reaches could not cover its width, despite alternating the brush between left and right hands. So at each ladder height, I had to shift the ladder position to left and right. Then, I retracted the ladder extension to lower its height. Rinse and repeat. Each setup required unknotting then refastening all the ropes and clamps. No short cuts were taken to set up the ladder at each position. That's why it took a long day to hand brush that chimney. And that was just the chimney facade and not even its sides. However, I won't bore you with the set up for rest of the house.
Another note: In the photo, the top of the ladder as shown is the same height as the smoke alarm that I had to replace the battery once. However, the smoke alarm is over the loft area, which is about the same height as the scaffold top. So, I had to bring the ladder up to the loft and extend it just as far. Though the scaffold was quite stable, it did not offer the psychological comfort of the larger loft, even though it offered just a good a base. There was still the danger of the ladder top skidding sideway sending me tumbling to the living space 25ft below. So, I had to use guy ropes to secure the ladder in a similar manner.
Now, if the spot lights over the living space burn out, I would not be able to use my 20-ft ladder by itself. I would need a scaffold/ladder to change them, or get one of the super long light-bulb-changer-on-a-poles.
Conclusions: Despite all the precaution, calculations, and common sense, it is difficult to overcome the fear of height. I have less acrophobia than most people, but when up on that ladder, it felt scarier than one should rationally be. The reason was that the scaffold was set up on the deck that was more than 6ft above the ground which continues to slope down (it is the side of a hill). When I was up there, I could see more of the highway that was 1/4 mile away, and I could hear faraway birds chirping. But it was not something you enjoyed on a ladder. I always know I can never be a mountain climber.
Think about it! Anyone can dance on a stepstool 2 ft off the ground. Raise it to 20 ft, and most would need something to grab or they would fall. It's all in your head, folks. Now, how did the carpenters build my home? I never thought of asking them, but I will the next chance I see them.
Quote:
Originally Posted by calmloki
Hey there death wish! Bet you would have felt silly as the ladder pushed the top of the scaffold out from the house, leaving you flat up against the ladder and chimney for a moment before the ladder rotated around the guy rope...
... what part of AZ?
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I hope that I address your concern with the above post.
This is in the eastern part of the state, the region called the Mogollon Rim (see Wikipedia), with elevations of 6000-7000 ft. The nearest incorporated town is Showlow. A bit more to the east and closer to New Mexico is a place I like but couldn't afford called Greer with elevation from 8000-9000 ft. I saw your recent thread of a tour through AZ, but you miss this part. It's green and "wet" (for AZ that is), but of course you have plenty of that in Oregon.
Quote:
Originally Posted by REWahoo
NW-Bound, a couple more home maintenance projects similar to your scaffold and ladder job and the "RV" below will be perfect for you:
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No thanks! Even for a guy like me, that RV has no headroom. Where are the bathroom, kitchen, toilet? Save that for Dracula!
Quote:
Originally Posted by CuppaJoe
... figured you were on a trip (maybe to Paris)
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That would be nice! However, I wanted to see my wallet re-inflate a bit more. Saving money on this staining job also helps.
Quote:
Originally Posted by FIREdreamer
Holy cr@p NW-bound, you could not pay me enough money to climb on that ladder!
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Obviously, $4K would not be enough for you! I am hoping the amount I saved will be even more, as this hand-stained coat should last longer than a mere "glazing" a painter would spray.
Quote:
Originally Posted by freebird5825
I hope this was a 1 shot deal for you, and you concluded the following:
1. Never again  ... |
No, perhaps not the same way. One can always make improvements.
I saw that Lowe's has a 32-ft extension ladder that allows me to go up to the top in one fell swoop. The fear factor is not reduced however, and might be even worse. Such a long ladder may be even more "springy" when you are at its center, I wonder.
Or how about 3 levels of scaffold, hence allowing a shorter ladder? At 4 levels of scaffold, I would need no ladder. Perhaps this foursome stack was the way the carpenters did it. The scaffold stacking can be done by one guy, in fact I built up the 2 levels myself. However, one may lose his balance by acrophobia, or end up dropping a scaffold component. I can visualize a scaffold piece bouncing off the deck and crashing through the glass doors.
To go higher, I would need a helper, but my wife only felt comfortable going up to the 1st level. To stack the Nth level, you need to bring its components up to the N-1 level, then stand on this lower N-1 level to stack it. The only difference from erecting the first level on the ground is acrophobia.
I've got a few years to ponder the next setup. Come on! This is nothing compared to tall buildings.
Quote:
Originally Posted by Westernskies
Look like we need to nominate you for the Extended Reach Ladder Hall of Fame. Here are some of your fellow Hall of Famers; from the International Division:
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Eh, I have seen these photos before.
Quote:
Originally Posted by Meadbh
I hereby nominate NW-Bound for the 2009 Darwin Awards!
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Gee! No thanks for your vote of "no confidence". I wish I could invite you up my ladder after you have read my scaffold analysis to convince yourself that all would be well, as it indeed turned out. One must conquer his/her fear, just as with investment. Buy, buy, buy, I said time and time again late last year and earlier this year. By the way, congrats on your Au purchases a few months ago.
. Back to more practice....
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