Astro Photography

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Replacing the old roll off roof

   When I first built the observatory a few years ago (~2003) I wasn't sure how well everything was going to function, so I used less than premium material to construct the roll off roof...well it worked just fine and sure made an "evening under the stars" much easier and tons more fun...but I now have to pay the price for skimping on the material...finally one of the main structural members failed and now it's easier to build another vice repair (Aug 2006)...Oh well, I wanted to raise it a couple inches anyway...

   Below are some pictures of how this one was done...there are lots of styles and methods to building "roll offs" but this was what I chose...with some basic tools, it's fairly easy to do...When I started the new roof, I could hardly believe that I could still see most of the original full size cross sectional drawing of the first roof on my work bench (I only laid out the drawing from the center line to one side because it's symmetrical) and therefor was able to recreate it vice reinventing it...Hope this sparks some ideas!

   Well, it's October 2013 now...and yep, the second roof has failed. Both the 1st and 2nd versions were only painted on the outside exposed to the weather. The 3rd version is constructed nearly the same as before but with some changes for the better I hope. I built it with the same design and then inserted new pixs (2013) at the point where things started to differ.


 

The Start

   Really hard to believe that I could still find enough of the original drawing on this bench to reconstruct the curvature of the original...this is the full size "half" template used to make most all the parts                           

Laying out the first part

  This is half of the cross sectional view of the roof...to get the other side all that is necessary is to flip the template over and line up the center line and the bottom cut line...these parts are 3/4" plywood

N/S ends and intermediates

  There are the 4 main "ribs" North, South, and two interior ribs...the roof will roll on a track running North/South

Routing slots for the interior ribs in the side rails

  The side rails are 2x10's and require a slot for the interior "ribs" to fit into to make a strong joint...everything will be glued and screwed together during final assembly

Installing doublers

  The North/South members require doublers instead of routed slots...again 3/4" plywood

Installing the wheels

  The wheels run in steel track already on the observatory from the original construction...these wheels are the 7" solid rubber lawnmower type with ball bearing centers...two on each side rail held in place with 1/2" x 4 1/2" long bolts, flat washers and lock nuts

Main members ready for trial fit

  Here are the 2 side rails and N/S ends ready for trial fit

Putting it together

  Now it's starting to look like something...no glue yet

Most of the main members

  Most everything but the actual polycarbon roofing panel supports (1 1/2" x 1 3/4" strips to fit in the cutouts) have been fastened together

Yeah, that'll work

  Most of the fasteners so far are 3" long course thread deck type screws (with weather proof coating)...the original roof was completed right here and lifted to the top of the observatory (weighted 140 lbs)...as I took this picture, tropical storm Ernesto was starting to fill the sky with clouds/rain (Aug 31, '06) therefore, I will have to take it apart so it will not get soaked before any protective coating are applied...

Yet a 3rd new roof in October 2013

Fast forward to October, 2013...My second roof lasted about as long as the first and is crumbling (wood rot). This version is built nearly the same (I removed the unpainted wood after this picture), but what is different is I used pressure treated wood and then covered all exposed surfaces with aluminum trim stock, shaped to fit.All construction prior to this step is the same as the previous roof.

Another view

I raised it up onto my flat deck roof and installed the trim stock there as a precaution against dinging the trim stock during the hoisting up procedure. You can't hide a ding in this thin metal. I caulked all joints with white silicon rubber before I put it in the tracks.

In the tracks finally!

This is the second major change...galvanized sheet metal roofing vice polycarbonate. I removed the extra roof supports because when I looked up how many fasteners to use on the sheet metal, I discovered I didn't need the extra support. This is the first row of "5V raised sheet metal galvanized" roofing. I pre-measured and cut one side to center up the material. This is the most important row as it determines how the rest will lay out. There is a bed of silicon caulk all around the perimeter of the roofing

The second row on

The sheetmetal is held down with 1" long x#10 self drilling metal to wood coated screws with neoprene coated washers.

All finished

Still have to crimp the edges down a bit for a drip edge and round the sharp corners...and yeah...remove the old monster!

Another view

It was a bright sunny day when I installed this sheet metal and I had to wear dark sun glasses because of the glare off the shiny surface. I think after it weathers abit, I'll coat it with that white trailer roof coating material...that is also supposed to reflect about 40% of the heat.

Side view

Not sure how the cost compares to the previous version...the metal roofing is actually cheaper, but the trim stock isn't cheap at all...probably totals a bit more but hopefully will last longer.

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