How to top off your roof with spires, finials, domes and cupolas
Spires, finials, domes and cupolas can give a building a sense of culturally significant design. When correctly installed, buildings are enhanced and remain beautiful for years to come.
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| Photo courtesy of West Coast Weather Vanes |
Cupolas
A cupola is a highly ornamental, accenting structure mounted on top of buildings and usually centered in a prominent position along a roof ridge line. The word cupola means “small cupo” or little dome. Usually made of vinyl, copper or wood, they come in one piece
(or if larger) two or three pieces. Multiple-piece cupolas make handling and lifting easier. While some cupolas are simply decorative, others are functional. Functional cupolas provide ventilation to buildings by allowing moist air a place to escape. A decorative cupola differs from a functional cupola in that the roofing material and roof sheathing do not need to be cut away to create a vent hole.
Weather vanes are traditionally located at the peak of the cupola in a prominent location. Most cupolas have internal access
(for ventilation or maintenance purposes) and a cross brace as a structural support onto which the spire (vertical installation rod) can be mounted using a cupola flange. Correctly cutting out the cupola base measurement angle to fit on the roof is important. To do this, determine the roof slope. One way to do this is with an angle finder. When placed on a roof, it will indicate the slope of the roof in degrees; a 4:12 roof for example would have a slope angle of 15 degrees. Make sure the angle finder rests squarely on a shingle if you have a shingled roof, and not across layers of shingle rows. Record the roof pitch angle and prepare to cut the cupola’s base components to fit the roof.
Another way to determine the roof slope is to cut and remove the ridge cap where the cupola will be installed. Take two 1×4-inch boards, two strips of cardboard or two rulers, and set them, on edge, straddling down opposite sides of the roof ridge. Center them against the peak center of the roof. Hold them tightly together at the top and carefully lift them to maintain the roof slope angle. Doing this will provide an accurate and symmetrical cutout template of the roof slope angle.
Again, the cupola base must match this roof slope angle. Transfer this angle to both sides of the cupola by tracing with a center line the angle formed under the wood/strips/rulers. Cut the cupola along your marked line starting cuts at the corners and ending at the center. Many cupolas come with molded, standard 3:12, 4:12 and 5:12 pitch lines on them. Steep roofs with a greater than 9:12 slope may need to have an extended base installed. Measure and clearly mark where the center of the cupola will be located. Don’t place the cupola over a supporting rafter.
Decorative cupolas can be installed with screws on four, predrilled 2×4-inch wood mounting blocks with some roofing cement and silicone caulk under the blocks. Set the cupola in place on the roof. It should be snugly fastened into the sides of the mounting blocks with two to three stainless steel screws. Plug or patch the screw holes, and caulk where the base and roof meet on the angle sides.
For functional cupolas, cut the appropriate size hole centered at the marked cupola location. Center the cupola over the hole, drill pilot holes (if desired) and fasten it using fasteners⎯most manufacturers recommend four per side. Prior to installation, run a thick bead of white caulking on the underside of the base to enhance the seal. Installing metal or aluminum flashing is also recommended 12 inches on each cupola side to prevent leaks. Finish the ridgeline with roof caps that fit tight against the cupola’s sides.
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| Photo courtesy of CopperCraft |
Spires and Finials
A finial is an element marking the top or end of some object, emphasizing the apex of a dome, spire, tower, roof, gable or any other distinctive ornament at the top, end or corner of a building or structure. Spire and finial installation frequently depends on their size. Often, their installation method is dependent upon the individual site conditions and customer preference. In most cases, they arrive at job sites delivered in sections, except for one-piece units, ready to be installed with the roof slope angle already provided. Bolts are usually provided to assemble the various components, but installers usually provide the connections that anchor the base unit to the roof.
Finials are available with or without a roof cap. A roof cap (or roof mount) will hold the finial. Without a roof cap, drill 3/4 of an inch into the roof peak to hold the finial’s bottom. For ridge, hip and multi-sided applications, most spires have square bases. For turret applications, spires come standard with round bases.
“A smaller spire or finial can be installed with stainless steel screws after making sure it is straight and level,” says Guenther Huber-Delle, president of CopperWorks Corp., Decatur, Ala. “The larger ones should always have an ‘under construction’⎯a stainless steel post (round or square) depending on [the ornament’s] size and shape⎯which needs to be mounted on the roof rafters with screws. Check that it is level; the finial/ spire could slide over the post.”
Ginny Bruce, inside sales rep at CopperCraft, Grapevine, Texas, explains the installation this way: “On spires the mounting brackets or mounting ring screws directly to the substrate. Then the spire is slipped over the mounting bracket, and either pop riveted or screwed to the bracket. Some applications come with a mounting rod attached to the spire that extends 6 to 12 inches past the bottom of the spire. The contractor will follow the same steps with the mounting bracket and fasten the nut from the underside of the spire for attachment. The mounting rod is dependent on the spire size.”
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| Photo courtesy of CopperWorks Corp. |
Domes
Hemispheric domes add a dramatic look to any building. They are curved structures with no angles or corners that enclose a lot of space without supporting columns. Most are self supporting because of their design. Because of this, most are considered freestanding with no requirement of any superstructure for their erection.
Dome installation is usually done from its inside directly onto the structure. There are many anchoring and/or attachment systems available to meet their numerous design applications. Many simply have bolt or screw-attached flanges where the dome sits on the structure. Depending on the diameter, the geographic and physical locations, reinforcing kits are available. They “hug” the inside wall of the dome and can be applied without detracting from the dome’s aesthetics.
But unlike cupolas, domes have different installation requirements because you can’t cut the roof pitch into them. “They have a flat surface,” says D. Gale Graf, owner and president of CFBS Inc., Anderson, S.C. “You will not always have a flat surface to install on with a standing seam metal roof.”
Up in the Air
These ornamental products must be raised to the roof to install them. “Most spires/finials can be carried by hand onto the roof,” Bruce says. “For larger items such as cupolas or chimney pots, these items will need to be lifted onto the roof using a forklift or small crane. All of our CopperCraft products come packed in plywood boxes with bottoms to aid in lifting. There will also be a lifting lug provided with the unit.”
Frequently cranes are the only way to hoist the product. “The size and reach of the crane will depend on the size of the product and the size of the building,” Graf says. “You need to know how to lift the product or you can destroy it. We want the crane to have a reach significant enough so when it pulls up along side of the building, the product doesn’t bang into it.”
Graf likes to ship his domes in one piece; that way they can be lifted from their top. But he explains: “It depends on the nature of the dome. It depends on if there is another section that sits on top of the dome. Either they hook on the edges with straps, or they can cable it and lift it from the center of the dome if there is an opening in the dome. The domes are structurally strong enough to do that.” With spires, Graf cautions not to lift them from their tip because this is usually the weakest point and is not built to serve as a hoist point. Be sure to use wrap straps. Also, Huber-Delle advises to always adhere to OSHA regulations.
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| Photo courtesy of West Coast Weather Vanes |
Up to the Installer
These ornamental roof products are designed to be installed by any competent builder, installer or contractor. Always follow manufacturers’ instructions and industry standards when installing. However, Graf cautions that because of liability today, manufacturers are reluctant to put a lot of instruction in writing. Also, “We don’t make any money installing and it’s a higher risk,” he says. “We prefer having our customers install themselves, but, I’ll give customers as much time as they need on the phone. I’ll go to sites sometimes and talk them through it, depending on the size of the project.”
Because every building is different, exact installation techniques will vary. “There is no installation rule book that exists that includes every shape and size of ornaments,” says Huber- Delle. “It must always be up to the architect/ engineer/installer, who will be in the end, responsible for it. The mounting of any ornamental piece is up to the installer and if he is not comfortable, he should always get an opinion from the engineer. There are new inventions and developments every day for the tools for the installation of ornaments. However, the traditional methods always work. The OSHA regulations are also constantly changing.”
Bruce advises to consider the mounting you will need prior to the construction start date to ensure the simplest, most secure method.
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| Photo courtesy of Copperworks Corp. |
