Knowing your roof type is a vital part of installing solar: each roof type has a different mounting technique to ensure you're protected from the elements, and installing with the wrong hardware could lead to roof leaks.
This article will explore different roof types, as well as help you know how to discern which type is on your home.
- Asphalt Shingle
- Flat Roofs
- Wooden shake
The most common roof type in the United States is asphalt shingle, and for good reason–asphalt shingle roofs are reliable, affordable, and effective in most environments.
|Shingle roofs come in all sorts of colors, but they're pretty easy to point out.
These roofs consist of pliable shingles made of an asphalt-saturated base padded with stone granules. These shingles are then layered over the roof face, providing strong waterproofing.
If your roof is made of layered, thin shingles with a rough, sandy exterior, you most likely have an asphalt shingle roof.
There are two main types of metal roofing: corrugated metal and standing seam metal. Stone-coated steel is a third technique that can also be considered a “metal roof”.
Corrugated metal roofing (also called screw-down metal roofing) encapsulates many different metals, but generally consists of steel, aluminum, or copper sheets shaped into alternating ridges and grooves (think wavy potato chip).
These sheets are placed on the roof face, edges overlapping. They are then attached with nails or screws to form a durable covering.
You most likely have a corrugated metal roof if your metal roof does not have raised seams (see below).
Standing seam metal:
Standing seam metal roofing is similar to corrugated metal, but with one key difference--instead of being attached by drilling/nailing the material directly to the roof face, standing seam metal is attached over clips that are drilled into the roof.
The metal panels connect with a protruding seam, locked into the drilled-in clips.
This feature makes standing seam roofs last longer than many other types, and does a great job at keeping moisture out.
This additional durability does come at a higher price, with standing seam metal roofs coming in at one of the more expensive roof types.
If your roof is metal with raised seams and no visible roof penetrations, chances are you have a standing seam metal roof.
Stone coated steel roofing is a less common metal roof type, and consists of metal sheets, shingles, or tiles coated in stone granules. These are then installed according to their shape.
The aesthetic versatility of stone-coated steel is a big part of the appeal--it can imitate most tile roof types. It's also generally durable.
However, walking on this roof type can crack and chip the coating on the metal.
It can sometimes be difficult to ascertain whether you have a stone-coated metal roof at first glance, particularly because they can appear similar to various other types.
One way to tell, however, is to look at each individual tile. Standard clay/concrete tiles interlock with each other, while stone-coated steel's imitation will typically appear as a stamped imprint of multiple roof tiles:
|Stone-Coated Steel vs. Clay Roof Tiles|
Important note: Due to its brittle nature, Project Solar does not currently offer options for stone-coated steel roofing.
Tile roofs are another common roof material, especially in California, Florida, and other warm, coastal areas. Two of the most common types of tile roofs are concrete and clay.
Concrete tile is a robust option for roofing, and concrete tiles come in a variety of styles and colors.
Concrete tile is less brittle than clay tile, but it can be susceptible to staining and moss or lichen growth (less common with clay tile).
If you have thicker roof tiles with a more porous texture, you most likely have a concrete tile roof. Looking at the base of the tile can be a good idea as well, as concrete tiles are usually more rough on the ends.
Clay tiles are thinner and smoother than concrete tiles in most cases. For this reason, they're more fragile to walk on.
Regardless, clay tile roofs can last for a hundred years, especially with proper maintenance. They don't absorb as much water as concrete tile, which prevents them from staining and lichen or moss growth.
S-shaped, terracotta-colored tile is usually clay, but concrete or synthetic tile can mimic this look. When trying to determine if your roof is clay tile, look out for a smooth surface that is less porous.
Another tile-esque roof type is slate. Slate tiles are essentially slate rock slabs have a very low absorption rate; they're also completely fireproof.
Like its tile siblings (even more so), slate roofs are durable but brittle, which can cause issues with maintenance--however, they're made of rock, so they can last for hundreds of years with little to no maintenance.
Slate tiles generally look like rough hewn rock, though this may be less exaggerated in some instances. The way slate splits (in sheets) causes an almost wave-like impression on the stone.
Some companies also offer synthetic slate roof tiles.
Important note: Project Solar does not offer options for slate roofing.
Flat roofs are more common in arid climates, where water drainage isn't as much of an issue. There are many different flat roof material types:
Built-up roofs (BUR):
Also called tar and gravel roofs, built-up roofs have a dense layer of tar and gravel that means they're generally pretty durable. However, if leaks occur it can be difficult to ascertain where they're coming from for repair.
These roofs therefore aren't recommended in areas with regular, severe inclement weather.
If your flat roof has a dense, built-up gravel surface, it's likely that you have a built-up roof.
A modified bitumen roof is a 5-layer covering with a final layer similar to a built-up roof. Modified bitumen roofs typically have a much smaller grain than built-up roofs, however.
This roof type is commonly applied with either heat or cold to adhere. Its sheet-based installation contributes to a quilted appearance with a similar texture to an asphalt shingle roof.
EPDM rubber is a single-ply roll-on roof type, usually coming in black or white. This material is either glued, fastened, or weighted down to attach it to the roof.
It can sometimes look similar to a built up roof, if it's weighted down with stones (though these stones would usually be much larger).
Flat roofs made of thermoplastic membrane are either made of polyvinyl chloride (PVC) or thermoplastic olefin (TPO).
Both of these materials are comparable, though PVC tends to last a bit longer.
Thermoplastic membrane roofing is attached to the roof with plates and screws, and it's usually white or gray.
Since it's been sprayed on, polyurethane foam has an easily recognizable appearance: it molds to the objects that it's sprayed onto.
It leaves no seams, which is amazing for waterproofing. This convenience can also lead to a higher overall cost, but it can definitely be worth it in some cases.
Rolled composite roofing is one of the least expensive roof types. It's asphalt-based and mineral surfaced, with a similar texture to a composite shingle or modified bitumen roof.
Rolled composite roofs are generally used for uninhabited structures like patio covers, sheds, etc, because they usually don't last as long as other types.
Wooden shake roofs are not common in most areas, but synthetic imitations have brought their popularity up recently.
Wooden shake roofs are made of wooden shingles, sometimes treated or covered with fire-resistant chemicals.
Shake shingles' natural, irregular wooden look make them easy to spot--although, they can come in different colors and sizes.
Important note: Project Solar cannot offer any options for wooden shake shingle roofs.
Installing solar is a big decision that can affect your roof, so it's important to stay as informed as you can throughout the process.
Knowing your roof type is one of the first steps, as solar mounting hardware will vary based on which roof type you have. In some cases, this can impact pricing as well.
If you are a Project Solar customer, make sure to notate the correct roof type on your Customer Information Form, or, alternatively, let your Onboarding Specialist know--they'll be able to inform you on the options available for your home.