Roofs: when and how to detail?

[whitman500]

I've seen in some of the discussions about detailing buildings that you should consider detailing roofs either as a gravel roof (with ballast) or a tar paper roof (with sandpaper painted black). The question I have is are there any general rules about when each type of roof would be used versus a simple, painted roof of smooth wood planks. I'm beginning to construct buildings for my layout and am trying to decide which roof detailing methods to use on which buildings and wanted to know if certain building types were more likely to have one then the other.

[Javern]

I've never seen a roof of just wood planks, wouldn't it leak? You could hav a tin roof, shingles. I think the majority of roofs around are tar n gravel

[Bikerdad]

The detailing on roofs is very dependent, on timeframe, the nature of the building and location.

A 1930's Delta sharecropper's shanty roof won't have anything on the roof except maybe a chimney. A 21st century light industrial rooftop will probably have air conditioner(s), access panels or stairs, plumbing vents, maybe even satellite dishes. The shanty will be tarpaper or tin, the industrial roof will be flat and tarred, maybe with gravel. A 50's vintage mountain retreat is probably going to be slate, maybe asphalt shingles, steeply sloped with a chimney and plumbing vents coming through the roof.

Depending on your era, you can get a lot of info on roofs from photographs. Of course, if you're doing modern, just find someplace where you can look down on the sort of roofs you want to model and see for yourself.

[orsonroy]

Definitely look to period photos for your roof treatments. They're all over, but sorta hard to dig up. Online, more and more universities are starting to upload photo collections, so they're a good place to start (check the University of Indiana and Duke University for FANTASTIC collections). The Library of Congress has almost 100,000 (!) images online, so don't neglect that overwhelming source.

[bogp40]

Whatever roof style/ detail you use, here's a few modeling tips. For tar and gravel- the most common flat roof-Wet or dry sandpaper contact cemented to the styrene will last many years without lifting or curling. For extremely large flat roofs you may need to add additional backing to the styrene roof material. Of coarse the wall angle are used for most kits. There's so many options available w/ the chimneys, various pipes and vents, roof hatches to stairwells, ventilation from turbine vents to A/C units. For added detail don't forget drainage scuppers and downspouts. A small styrene shaped block w/ a #12 or #10 copper wire makes a great downspout, Washes of pullman green and touch of weathering make the most realistic copper. Looking a many pics and just studying roofs is all you need. Add what you think would be appripriate for the era and use. Bob K.

[cwclark]

I build roofing material from different things...for a tin roof, i'll use sheet "tin roof " by evergreen styrene plastic and paint it light gray and silver...for tar roof i'll use a couple of ply's of toilet tissue glued over the original plastic roof from the building kit, painted black or i'll use sandpaper glued down and painted black...and if i really want detail i'll make a shingle roof from cigarette rolling papers individually cut into the shape of the shingle and glued to the roof then, paint them in grays or tans...Chuck

[revandy]

New England roofs especially old victorian homes and small mill buildings with pitched roofs had slate roofs, flat roofs were predominantly tar and gravel, and rubber membrane roofs started to appear in the 60's. I haven't seen to many seaside diorama's that showed a widow's walk on the roofs.

[Anonymous]

The original question here asked about construction methods for "flat" roofs. Fact is, there really isn't such a thing as a truly flat roof in the real world -- at least not on a building constructed by a competent builder. A "flat" roof eventually would settle in spots, resulting in the ponding of water, which would sooner or later destroy the roof.

So-called "flat" roofs are designed and built to channel rainwater or snowmelt to drains. Those drains may be in the form of gutters (along the entire "low" side of the roof); to scuppers located at points along the perimeter of the roof; or to interior drains, located away from the roof perimeter. In any event, the "flat" roof will be slightly, and possibly complexly, pitched toward the drains.

Most flat roofs are covered with layers of felt, which are adhered with hot bitumen (tar). Interestingly, these roofs are known in the construction trades as "built-up" roofs -- which refers to the application of the felts in layers.

The top layer of felts may be covered with gravel ballast. This is an optional practice, and may be done for the most part to resist the uplift of wind over the structure. It isn't uncommon to see "tarred" roofs right alongside buildings with "ballasted" roofs. Builders' or designers' choice, but the larger the roof surface, the more likely it is to be covered with ballast.

A properly pitched "flat" roof on a model is unsusual to see. But when it's there, it conveys the same subtle but powerful sense of realism you get with a properly drained model railroad right-of-way.

[Anonymous]

Instead of going through all the trouble of painting sandpaper black, try grip tape. I bought black grip tape for my stairs to my baserment made by 3m and as I was bringing it down stairs to put it on it dawned on me to use it for roofing instead! (and after breaking both legs in a nasty fall down my stairs 2 days later I think I mave have been a little to impatient! JK!)

[Bikerdad]

Why paint sandpaper black? Unless you're doing O Scale, you can use Wet-dry 220 grit for your asphalt roof, its already a dark grey. Heck, there may even be wet-dry sandpapers in larger grits.

[Anonymous]

QUOTE: Originally posted by fiverings

A properly pitched "flat" roof on a model is unsusual to see. But when it's there, it conveys the same subtle but powerful sense of realism you get with a properly drained model railroad right-of-way.

A properly pitched flat roof usually has a slope of between 1/8" and 1/4" per foot. And due to the enormous load on a building's structure created by standing water, roof drains are rarely more that approximately 60 feet apart. At 1/87 scale the slope would then be so minimal that it's probably not worth trying to properly model especially with a ballasted roof system. But proper location of roof drains ( and overflow drains 2' to 4' away from each roof drain) would create a very convincing illusion.

Details to consider for a "flat" roof building would include roof drains and overflows, at least one roof hatch if the building is taller than 15 feet or so, roof-top HVAC units for heating and/or cooling, exhaust fan housings, toilet vent pipes, walkway pads for access routes from a roof hatch or ladder point to equipment maintenance locations, a raised roof area where there may be an elevator below, anchor points for signage, cooling towers, etc. Any roof top equipment should be mounted on curbs and the curbs should have sloped "crickets" or drainage diverters. The use of the building will dictate some of those details.

A "flat" roof that would be worth modelling accurately would be one where the building would be perhaps up to 100' wide (and at least that long) where the steel roof structure was sloped to provide the drainage. There would then be a very definate ridge line. Water would be drained either by gutters or by scuppers and downspouts.

[CBQ_Guy]

Here's a tip for detailing modern day roofs I recently became aware of.

Many times when there is a police chase event on the news or even shown on some regular TV broadcasts, most of the video coverage is from a news helicopter. Our focus is normally on the vehicles, but recently my attention started noticing we are also getting a "birds eye" view of roof tops on all types of structures, too.

Next time one of these events comes up on your TV set, pop in a blank tape or DVD and record it to play back for reference later.

Hope this helps.