63A: Scaffold Addendum

After posting the last post I realized I hadn’t shown any close-ups of the scaffold, so you could see all the parts.

Here’s an annotated pic showing how the upper end goes together.

The base of the legs sit about 8’ out from the building, so it will take a lot of effort to push the scaffold away from the wall enough for it to fall over. Each leg is made from two 12’ long 2x4’s, overlapped in the center. In this pic the overlap is about 6’ long, so total leg length is 18’.

I also didn’t talk about how I get the scaffolds raised and lowered. To do that I attach my block and tackle to one of the purlins in the roof. Then it’s easy to hoist them up vertical.
To lay them down, just reverse the procedure. When laying them down, it helps if you get in between the legs, and lift the base of the scaffold a little off the ground and set the bottom brace on top of your butt. Don’t worry, all the weight is being held by the block and tackle. Then as you lower away on the block and tackle, just walk backwards slowly. That will keep the top of the scaffold from rubbing against the wall as it comes down.

From a safety perspective, while lowering the scaffold, realize that all the diagonal braces in the scaffold are several feet away from your body, so while it is lowering, if the block and tackle fails for any reason, you are not in a position to get hit by anything on the scaffold as it falls.

63: Home Made Scaffolds

During this project I have spent a lot of time building, using and then taking apart scaffolds. You have already seen pics of some of them here in the blog. While they did the job they were intended for; they also had disadvantages that would prevent them from being used on other phases of the project. Example: I built scaffolds to allow me to install the 2x8 fascia on the ends of each truss. Unfortunately, that they were directly connected to my outside walls prevented me being able to use them when installing housewrap and siding.

So, I am now in my 3rd generation of scaffold building. Each new generation brings a clearer picture of what will work better. Some may argue, why didn’t I just go ahead and buy a 2nd extension ladder and two “ladder jacks” in the beginning.

At one time I did consider hanging my walkboard from ladder jacks mounted on extension ladders. I only had one 20 foot extension ladder, and it is rated only for 225 lbs (a medium duty ladder). I also didn’t like how the ladder bottom just sits on the ground. I wanted something that I could more firmly affix to the ground. And finally, my gable is 25 feet high and I didn’t think I could get enough extension on a 20 ft ladder to be able to reach the gable when it comes time to housewrap and side it. In case you didn’t know, on a 20 ft extension ladder the max working height is only about 16 to 17 feet. So, long story short, ladder jacks and extension ladders weren’t the way for me to go.

How to move the walkboard up and down by myself, was another big problem. The walkboard is I estimate 80 lbs in weight. There’s no way I could or would try to carry one end of the walkboard up a ladder and then try to set it in the ladder jack. That’s a bad fall just waiting to happen (and then that walkboard comes crashing down on top of you).

I didn’t want to rent or buy scaffolds, too expensive, and time consuming to rig up and down.
So, I had to come up with something I could build myself out of readily available materials. But, most important of all, that they had to be safe. To me safe means stable (it doesn’t wiggle when I walk around on it); solid (no noticeable deflections in any members when I am working on it); portable (easy to move); easily adjustable (in height), reasonably lightweight (so I can move it around by myself).

So, here’s what I came up with. Let’s call then lean-too scaffolds. They are built out of 2x4’s, with critical connection points done with ½” bolts (plenty of shear strength). They lean up against the wall, but they are not connected to the wall. The legs are flaired out at the bottom, six or seven feet apart, so they won’t tip over easily. And finally, there are steel L-angles attached to the bottom of each leg. I drive rebar stakes through a hole in each L-angle 10-12 inches into the soil. This way the bottom of each leg is firmly held in place. The scaffold isn’t going anywhere.

There’s a vertical member (2x4, 12 ft long) that hangs from (bolted to) the upper cross piece. It hangs maybe 4” from my exterior house wall, so I have room to get my siding in there to attach. Where ever I need to place the walkboard I can connect a horizontal brace and then set the walkboard on it. To raise (or lower) the walkboard I just attach my block and tackle to the upper cross arm, lift it up to the height needed, then attach a new horizontal arm.

So far, this system has worked well. I’ve used the walkboard at three different elevations; I still have one more “raising” to do. At the final elevation, the walkboard will be pretty much up flush against the bottom of the upper cross arm.

So, the plan is to side the building, moving the walkboard up as necessary to keep the work at a comfortable height (about mid-thigh to the top of my head). Once I get to the gable top, I will start painting the siding and lower the walkboard as necessary until painting is finished. Then, it’s on to the north wall.

One final tip: When the walkboard was 4’ and 8’ above the ground I was pretty comfortable being on it with no other fall protection equipment. Now, that my feet are 12 feet above the ground I have a ½” rope that is stretched tight from one gable end to the other. Everytime I move around up there I’m holding on to that rope for extra stability. It’s probably not “enough” in the way of fall protection, but enough would be both difficult and dangerous to rig up; not to mention, quite expensive. So, this will have to do.

Pic one is a “shorty” version of the lean-too scaffold I tried to test it’s usefulness. Pic two is the full size version with walkboard at 8’ elevation. Pic three is at 12’ elevation. Notice the cross members are now diagonal mounted. This makes the scaffold much more rigid and stable in use.
Disclaimer: While I think this design is safe for ME to use; I don’t extend that recommendation to anyone else. Build and use a homebuilt design like this at your own risk.