Refurbishing Grotto depot: Part 1 – On Cedar Roofing –

I built the Grotto, Washington depot a long, long time ago.  I think I found out about Grotto by looking at a postwar track diagram and coming into the possession of a print by the late Al Mitchell (a very, very good man who died much too soon). Al’s print was of a rather sad looking little depot sometime after the cement plant shut down. A  few windows were boarded up with plywood and the trim was in rough shape or missing altogether.  In short it looked like a building that begged to be modelled.  (There’s just such a  Robert Johnston shot over on the GN-NP Joint Archive linked to here: As I’d done Scenic depot in a similar neglected fashion Grotto seemed like a good next step. In short order  a model was constructed and given a coat of white paint with green trimmed window of acetate or packaging – whatever was to hand. The completed styrene components are shown below.

Grotto Depot before paint IMG_0401

In the years since then the model suffered a series of unfortunate incidents. First up was a trip to central Washington where the roof suffered lasting harm in the high summer heat. After that the depot was subjected to a lot mistreatment at my own hands, used as stand in for any planning cause that used the very standard 24’X24′ footprint of the depot.  When planning Grotto the module, the depot was of course a perfect stand-in, only on closer inspection did I realize the amount of work that lay ahead. As a result most of the rest of this post reads like a tale of what not to do…

For all of its defects the depot follows typical rugged milk carton construction – the structure walls forming a socket for the removable roof which has its own set of internal gables. As first constructed the model roof used a layering of styrene followed by contact cement, thin thin vellum or tissue, PVA and finally shingles cut from paper bag strips, slit, chalked and stained with acrylic inks. As one can imagine , even using the thinnest of materials you get a lot of stack-up. The contact cement in particular caused a lot of grief. On subsequent roofing projects I tried creating a recess to hold most of the stack within  the barge boards but when this idea failed on roofs with open rafter tails I changed over to painted masking tape. I figured that I wanted to do more than just make shingles and with masking tape you make a streaky brown-grey mess, cut it into strips and lay it down either on the roof substrate or in my case on an indexed plexiglass sheet, the lot then being unstuck as a group and repositioned on the roof proper. Then you’re done.

The problem with masking tape, apart from the possibility of de-lamination, is that while thin on application, subsequent handling causes the cut line along the gable ends to recede into a slight bulge. You can see what I am talking about in the photo of the Skykomish A-frame. In this case I’d gone to the trouble of recessing the contact cement and the vellum the tape shingles attached to only to have the shingles bulge to almost two scale inches at the lap which is double what they were starting out. In the case of the A frame I’m not as worried as it has much thicker barn shakes and not the decent cedar seen on a railway depot. For depots we need a better solution.


What to do… To be honest I still am not entirely sure but I had a small amount of experience modelling asphalt shingles as single .005″ styrene panels and so I figured why not try my hand at styrene cedar roofing. In styrene shingle panels I’m at least back to having a stable, more archival process. Unfortunately it doesn’t really do the job. The gable edge is half as thick of course but there isn’t the look of one shingle on top of the other, of the heave that shingles get after about a season. It is also tremendously demanding work scribing a large panel for rows and then scribing the whole lot randomly for individual shingles. Every scribe that starts too early or finishes too late makes the end result less presentable.

In the end I’ve opted for individual shingle strips. They’re small and finicky but being the same material as the roof substrate greatly simplifies glueing them down. They’re also  lapped, giving that little bit of dimension. Although I haven’t done it to the depot yet, the combined thickness of the shingles along the gable edge can be reduced with a good sharp no. 2 barrette file to something a little closer to scale.

Before shingling could start I had to make a new roof substrate. For Grotto I used .030″ material scribed around the perimeter to represent the sofit boards. I couldn’t use scribed siding  since on the prototype the boards parallel the walls. Ten thou thick  barge boards were applied on the edge and then I tried something a little different in applying the small barge board trim. Instead of wiggling little bits of .005X.010 strip around in the air,  a gauge was made and then wide strips of .005 were fed around the roof perimeter. When things were solid I trimmed the excess with a sharp knife. I use this dodge in other realms but this was the first time I’d done it on a styrene roof. It works but it is a bit wasteful.

IMG_0883 copy

The shingle strips were made from .005″ sheet taped to a piece of ply with one edge against a stop strip and then scribed using a square. An hour or two later I cut the strips out to a height a touch less than twice the exposure. I used a partial starter strip of the same .005″ material but used half height material and then filed/ sanded a small taper to the top of it after installing. From there the shingling was just a lot of caliper and straight edge work until I got close to the top and then started from the other side and worked my way up. Doing so allows the wayward modeller a chance to even out any errors in the last 7 or 8 rows of shingles.

The photo below shows the shingles left long. To trim them I used a bit of shim placed between the barge board trim and the knife blade.

IMG_0885 copy

I wasn’t entirely sure what to use for the flashing but in the photo it looks like  I’ve opted for a bit of sanded down .005″ styrene. A notch has been filed for the old chimney which means I’ll be using it or one the same size. Aside from chipped paint and missing plaster “mortar” I don’t think it looks too bad. The size and shape look faithful to the prototype. Certainly looks better than that gap along the gable wall. I’ll need to investigate why the roof isn’t sitting down fully before too long.

IMG_0886 copy



3 thoughts on “Refurbishing Grotto depot: Part 1 – On Cedar Roofing –

    • Thanks,

      The short answer is that I probably won’t be. That is difficult to absorb internally as I am a big supporter of local meets but I came to the end of the road with rivet counting some time ago. While I recognise that the local geography is somewhat different than RPM in the continental sense my aversion to the latter only grows stronger with the days and for all of the reasons I’ve listed before. North American prototype modellers are spoiled rotten and talk a lot (complain) but are rarely capable of doing their own work. Until that changes I’ve got better things to do.


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