I have been building models to live outside for over 17 years, but I am still a student when it comes to buidlign a durable, fine scale model. My first layout was on the coast in northern California, with salt air, and over 50" of rain each year. For the last 10 years, I have been building my layout in San Diego, with relatively no rain, but intense sun and heat. I want to share some of my successes and failures.

Roof Materials

The most vulnerable part of any building is the roof. This is true in the real world, and is equally true in the model world. I think that sun and ultra-violet rays are the most destructive part of the outdoor environment, with heat and rain adding to the mix. Assuming you use an adequate material for the substructure, the actual roofing material takes the beating.

The first buildings I built, I modeled roll roofing, using wet and dry sand paper for the material. I wanted a slight tooth to the surface to look like the grit on real roll roofing. I have used contact cement and silicone sealant to adhere the paper to the substructure. I then painted the roof with a good exterior latex, because I wanted a particular color scheme (inspired by the Southern Pacific). Most wet and dry sandpaper is black, and could be used as is. The paper gets brittle over time, and cracks at the seams. The adhesive fails and the edges fo the paper lift, making it more vulnerable to the effects of the weather. I discovered that I needed to use edge molding of 1/8" x 1/8" brass angle. This seals the edges of the roof.

This building, a little section house, is one of my oldest buildings, about 15 years. The roof has been repaired once already, and the edge moldings added. You can see that the seam at the peak has cracked open. The seams between the sheets are beginning to lift as the adhesive fails. I think I used commercial contact cement. I didn't put glue on the edge of the lower sheet, so the upper sheet isn't really glued down very well right at the overlap.

This building, the sand house, is about the same age as the first. The seam edges are lifting, and the bottom edge has begun to fall apart as little sections get brittle and break away.

This is the roof of my water tank. It was replaced over a decade ago, and I used silicone sealant to glued each piece in place. The edges have held up better, since they are actually glued down.

The next type of roof I tried was a real wood shingle roof. I chose some very tight grain, all heart, old growth redwood, and made shingle bolts. I then split the individual shingles off of the bolt, and tapered them with a chisel. This is a very time consuming process! Some people have used commercial doll house shingles, but I have found that the grain of the wood is not up to the task. Most doll houses don't live outside. I glued my shingles down to the substructure with ACC. I first tried a yellow wood glue, Titebond II, but that was too slow for me. Titebond isn't really water proof, and needs to be cured under clamp pressure to be the most water resistant.

This roof, on another small section house, is about 14 years old. A few years ago I repaired it. Some of the shingles had split and fallen off, and a few had eroded to become paper thin. I just fit new shingles into the spaces, and glued them in. If you look at the larger picture, you can see that the lower edges are beginning to fail, with the individual shingles splitting apart. I love what happens to redwood as it ages. The colors come up naturally with no work on my part. However, this is a very labor intensive roof system, and I haven't used it on any other buildings.

The next kind of roof I modeled was a standard three tab asphalt shingle, which is a very typical roof material. I had heavy paper laser cut to resemble strips fo shingles with the slots cut out between the tabs. I glued this to the roof structure with Titebond II, and then painted it with exterior latex paint. I used this on the first large industry building on my railroad. It is now called Southside Aloe Works.

This is a section which has held up well for over 10 years. I used edge trim angle, which is standard for me now. This really helps protect the edges. I used a dry brush technique to streak on a little white paint so that the entire roof has a little color variety. Time has added further color variations.

However, most of this roof has failed quite spectacularly in the last two years. This building lives under a tree on the south side of the house. I'm not sure what has caused this, but it looks like the paint failed, and the individual tab edges began to delaminate. There may be some kind of sap that comes from the water dripping off of the tree which has accelerated the process, and added the colors. Eventually this roof will have to be replaced entirely.

Last year I found a contract laser cutter to make me new shingles using a gasket material, which holds up better to moisture. I re-roofed this building using the new material. This is the result after 6 months outside. Some of the individual tabs have curled a little, but the basic roof is holding up well.