Sunday, August 28, 2011

Up on the roof

When we had our house painted - last January, for reasons I won't go into here - we had all the seams in the vertical siding caulked up.  (Vertical siding is a PITA.  Yet another lesson learned only after buying a house with that particular "feature".  But I digress.... )  When the spring came, though, and the siding dried back out, a lot of the seams popped open, which looked ugly and was going to let water into places I didn't want it.   So a major project to complete before the rains return is to recaulk and repaint all the seams that opened up.

Most of that effort involves only paint, a brush, and a ladder of one sort or another, but there is one wall over a fairly steeply pitched roof which took a bit more care.

That roof is shingled with Hardishake (another product that sounds a lot better than it actually works out to be, sadly, and another lesson learned only after buying a house using it, but again I digress.  Oh, and the picture shows day two of the effort.   I have already been up there to recaulk the seams, but yet again I digress.)  Hardishake is slippery and fragile, so climbing on that slope without safety gear seemed like a bad idea.  The above picture shows the roof with that gear in place.  Here's what it looked like to my wife, from the ground, while I was working up there:

That's about a 10 foot fall off the roof onto concrete - if it happens - and I really wanted to avoid that particular fate.  Alas I am not a professional climber of any kind and my gear is pretty limited.  I have two good - but not locking - carabiners, some cheap rope, some nylon webbing, and I bought a climbing harness specifically for this job.  That's it.

The rest of this writeup is for Chief Alex, who wanted to see pictures of what inanity I was doing to keep myself from being his next 911 response.  The rest of you may wander off or read on as you see fit now that you've seen the above pictures.

First, I anchored my safety rig to the house, around a half inch threaded rod that is exposed and goes through multiple redwood beams before being held in with nuts & washers.  Two independent webbing anchors (orange and yellow in the picture below) are tied with doubled webbing on either side of the beam.  Each terminates in a loop tied with something similar to, but not actually, a figure 8 knot and several safety knots.  Through those two loops I tied in my safety ropes.  I had only one, but it is 100' long, so I doubled it, and tied a figure 8 knot - the world's ugliest, I admit - with a loop that went through the loops in the webbing, and then a safety not or two and then tape.  Here's the resulting mess:

The webbing anchors look like this up close:

It's not obvious - our house is an architectural oddity - but the beam and threaded rod seen above are about eight feet above a flat roof, so I can easily get there to do the setup.  Then the lines go up and over onto the roof you cannot see from those pictures, and trail down on the shingled side as seen in the first picture above.  A pad is put over the corner of the roof just above the beam to protect the ropes.  Next I put on my climbing harness and clipped in like this:

Note that each rope is paired, and that each pair ends in a figure 8 knot with a loop and a safety knot.  The white and green tape seen above was for me to track which was which if needed, and each loop is really a pair of loops, so it's all redundant.  The carabiners clip each of the loops to the harness independently.

The goal was that for nearly all the time I was working any one thing could fail and nothing bad would happen.  If I lost a webbing anchor, I had a spare.  If I lost a single rope, it was doubled to the harness.  If I lost both ropes in a pair, I had a spare pair to catch me.

As the second picture shows, the risk was that I could slip, fall, and slide off the roof.  What I needed was something to stop my slide if that happened, rather than catch my full weight on a vertical drop.  The rig I arranged managed to do exactly that, and gave me an extra bit of leverage to move around on the roof with.

A challenge was that I had 15 feet of wall I am painting, and I had to move up or down the length of the wall as I worked on it.  I managed that with the dual, paired lines.  When needed I could move uphill a bit, unclip one of the lines, tie a temporary knot with a loop in it, and clip back in on that loop as well as the end loop.  That let me keep the rope short so that if I fell I would only slide a foot or two before stopping.  And, of course, I could work the other way, starting at the top with two shorter, temporary attachment points, work, then lengthen the ropes one at a time, always being clipped in to one or the other while doing so, then moving down the roof and working some more.

The biggest risk - I think - is that I was using non-locking carabiners, and that when I unclipped from one line to reset the length I was left on a single carabiner.  At all other times I think everything was at least doubled up.  Well, I suppose the harness itself counts as a single point of failure, but it's built to take some strain.

Anyway, the work on the sloped roof is done now except for putting a ladder up to sweep the debris down with a broom.  No more walking on fragile shingles.  I already had to glue a bunch back together as a result of this excursion and numerous others that have been done by painters, roofers, Internet connection installers, and exterminators over the years.

Thanks to Chief Alex for his training when I was part of the VFD - even if I only remember a fraction of it now - so that I could setup a system that let me get this job done with confidence and some measure of safety.  He would have done it very differently, I know, but given what I had to work with I think I did OK.

Lots more projects remain to be done before the rains get here, but I don't think anything will require this sort of rig again.