Here Phil builds a barn roof that has seen better days. The slates have been replaced at some point with corrugated iron and even this has rusted away or simply fallen off leaving the wooden supports exposed to the weather.
I'm using the Skytrex derelict barn as the basis for my model, but you could do this on any building in any scale.
Roof trusses are cut from 1mm by 3mm basswood strip. A cardboard template cut to match the end walls (40-degree slope either side for this building) helps assembly with wood glue. The top beams are cut from the same wood as the trusses and glued between them with thick superglue. 1mm square strips of balsa provide further support. Wobbly construction suits the scene, fortunately.
All the woodwork is coloured with EDM Models Weathered WoodStain. This turns the wood a nice silver but can run if applied heavily. As it happens, the effect is quite nice, so I'm not worried about it but still apply several thin coats, letting each one dry so I can judge the effect.
The model looks pretty complete with its woodwork in place, but many photos show that slate roofs were regularly replaced with corrugated iron, which then rusted away.
Since both sides of the iron sheet will be visible, it needs to be thin. For a OO model, some kitchen foil is cut to 24 by 10mm and then pressed onto the plastic corrugated roof leftover from a Wills kit. You could use corrugated plastic sheet if you prefer, my method is quite fragile and time-consuming.
The back of each sheet is primed and then washed over with some rust colour paint. Then they are stuck in place with UHU and the process repeated. Prototype photos show a virulent orange colour, but I've gone for a more subtle shade. A finishing touch would be a few dabs of yellow ochre or green weathering powders to simulate moss.
Looking to build a derelict signal box? Adapting your card kit can be a very enjoyable process, as we demonstrate in our article here with a Metcalfe LNWR signal box.
If you'd like to learn more about brush painting, watch our video here where you can brush up on your wood effect painting methods with Howard Smith.
Need more advice? Take a look at the BRM Techniques page for all our latest guides and advice articles.