It seems as though every church has its own, unique roof style. A church with a flat roof uses gravity to expel water, relying on drains and a waterproof membrane to protect the structure. The term “flat” is a bit misleading here — no roof should be 100% flat or you’d end up with a rooftop lake.
“Low slope” is a better description of what’s commonly called a flat roof. Low-slope roofs should have at least a 1/4 inch of slope per foot so that the water can flow downhill to drains to be distributed to the ground.
This material is sprayed directly onto the roof of the church, where it “foams up” and solidifies before a protective coating is added. Because of its flexibility, foam is especially useful for a church roof with unusual shapes or configurations.
A foam roof offers several advantages over other types of flat roofing systems. For example, it protects against thermal shock and greatly reduces your air conditioning bills.
Built-up roofing (aka BUR) is more commonly referred to as “hot tar roofing.” BURs have proven themselves a smart choice for over a century. Using multiple layers of asphalt felts, the process fuses together with hot asphalt.
After roofs have been built up, it’s smart to protect them from sunlight and foot traffic , using some kind of surfacing material – for example, gravel, a cap sheet, a smooth coat of hot asphalt or a type of special reflective coating.
Modified bitumen’s, like built up roofing, are made of reinforced asphalt impregnated felts. However, unlike BURs, the asphalt in the felts is modified (hence the name) with plastic or rubber polymers, resulting in elasticity, durability, and a better overall performance. Because of the added polymers, modified bitumen is often applied to the church rooftop in a single layer with overlapping seams. We can “glue” the roof with hot asphalt or an adhesive, or using propane torches, melt the asphalt underside. Some modified bitumen demand protective surfacing materials like mineral granules or a liquid coating.
Single ply membranes consist of rubber, plastic or even a hybrid of the two. As the name suggests, single ply membranes are applied in a single layer. The membrane is rolled out, the seams between sheets are heat welded, chemically welded or glued together, and then, the membrane is fastened to the roof with screws or flat plates, ballast or an adhesive.
SLOPED CHURCH ROOFING
The more traditional-looking churches have sloped roofs that use gravity to shed water. There are many different materials available, depending, of course, on your church’s style of roof.
Shingle Church Roof
Shingle roofs are usually reinforced with organic or fiberglass materials. Although asphalt shingles with organic felts have been around much longer, fiberglass-reinforced products now make up the bulk of the industry.
Tile Church Roof
Tile is a durable, long-lasting choice for a roofing material. Mission and Spanish-style round-topped tiles are often used in the Southwest. Flat styles are also available, helping to create a French or English look.
These days, tile roofs are available in a variety of colors and finishes. However, when you go with tile, you’ll want to verify that your church can actually support the load that comes with this much-heavier material.
These shingles make up an overwhelming share of the Valley’s steep-slope roofing market. It’s possible to reinforce them with organic or fiberglass materials. Even though asphalt shingles reinforced with organic felts have been around much longer, fiberglass-reinforced products are now the more popular choice.
Some churches have chosen this style of roof, made up of a fiberglass mat, along with top-and-bottom layers of asphalt, and mineral granules.
Fire Resistance Ratings
An asphalt shingle’s ability to resist fires, like most other roofing materials, is broken up into categories: Class A, Class B or Class C. Just like on report cards, Class A signifies the roofing material with the most fire-resistance. Classes B and C designate less fire resistance. As a general rule, most fiberglass shingles have Class A fire ratings while the majority of organic shingles have Class C ratings.
A shingle’s reinforcement has little effect on its appearance. Organic and fiberglass products come in laminated (architectural) grades that deliver a textured appearance.
You can also apply zinc or copper-coated ceramic granules to protect against such things as an algae attack, which are very common in warm, humid parts of the country. Both types of shingles come in a variety of colors.