Our R&D and Engineering teams have invested a lot of time in developing PV mounting solutions for tile roofs. Our end goal is always to provide installers with solutions that are easy to install, minimize your time on the roof, won’t break the bank, and that meet and exceed all known building codes.
Tile roofing is a completely different animal than installing on comp shingle, metal, or low-slope roofing, and like all roofing applications, there are many things to consider BEFORE you install.
Because we want all of your installs to be seamless and hassle-free, we thought we’d share some tips – if you have additional tips, please feel free to share them here! As I’ve always said, the more we share, the more we know. And that can only be a good thing for the industry.
- EVALUATE THE TILES
It’s common to find hairline cracks on tile roofs, the result of a dropped tool or a too-heavy footstep long ago. Often cracks are sealed together with silicone or some other adhesive. But just because you didn’t cause the blemish, doesn’t mean it’s not your responsibility. We’ve heard it again and again from the integrators we work with….regardless of who caused the damage, it’s always going to be the last person on the roof who will be blamed
- INSPECT THE UNDERLAYMENT
In 1986, the building code was updated to require underlayment on tile roofs, to protect homes from snow, sleet and wind-driven rain. No one says it better than our founder & President Brian Stearns: “I used to say that the tile was really a façade to protect the underlayment, which was your primary waterproofing. That’s probably a little bit of a stretch, but the underlayment is critical.” A thorough inspection of the underlayment before taking ownership of the roof is important. If the material is deteriorating, rotting or cracking, it could spring a leak regardless of what you happen to do on the roof.
- CHECK FOR PESTS
Tile roofs are ideal homes for bats, squirrels, birds and even rats. Damage from gnawing pests can lead to moisture intrusion, which will rapidly degrade waterproofing properties and the structure underneath. Pay special attention to holes and cracks on the roof. If you can, get inside the house and do a survey of the attic – this will give you a good sense of whether or not the roof has leaked in the past, or is currently leaking.
- KNOW THAT YOU WILL BREAK TILE
Everybody does. It happens on every project we’re aware of, and it’s important to fix the material as you go, or at the very least, before you finish the install. Damaged tiles really need to be replaced before/during the installation. Mounting solutions that replace a complete tile with a flashing are ideal.
- THINK ABOUT LONGEVITY
One way to install solar on tile roofing involves boring a hole for mounting posts through the tiles. The tile is placed over the flashing and post, leaving a gap between post and tile. One way or another, the installer will need to make sure the area around the post remains watertight. In the Southwest, caulking and adhesives won’t last the life of an array. Any time your solution involves “one way or another”, it should really lead to one question: Is this a 25 year application?
- CONSIDER TILE REMOVAL
The popular “strip and go” installation method has installers removing tile from the roof and replacing it with asphalt shingles. Solar is installed using typical flashing and attachment methods, and then the tile is reinstalled around the perimeter of the array so that it has the look of an array on a tile roof. In reality, the waterproofing layer is the asphalt shingles.
- INSTALL BRACKETS INTO RAFTERS
Structural engineers will sign off on installing into plywood, which will probably hold a solar array, but a strong enough wind could pull the plywood away from the roof because it’s typically held in place with just eight penny nails. Also, and this is a biggy: Use pre-drilled, backfilled holes for the lag bolts. Not doing so can split rafters.
- MINIMIZE ADDITIONAL WEIGHT
I’m telling you what you already know here: Tile is heavy. Limiting weight on the roof and gaining approval from a structural engineer will ensure structural integrity. Many installers I know wear soft-soled shoes like Vans or something similar. Make sure that when you’re doing your survey, you’re getting a really good feel for how the roof is assembled – this is essential prior to just jumping up there to do the installation. And beware: Even the heaviest tiles can be very brittle.
Do you have any other tips for mounting PV on tile roofing? Leave a comment!
Our Tile Flashing System is an innovative and straightforward solution that should be considered when evaluating your mounting options. It replaces a complete tile, attaches to the roof deck with as little as 2 lag bolts, is faster and much easier than tile hook systems, and is certified by IAPMO. Watch the install video and see how easy it really is to install.
Oh, and before I sign off, I wanted to let you know that if you’ll be in either San Diego, Portland, Oregon or Atlanta over the next few weeks, we’d love to have you stop by and see us at California Solar Expo booth 10, at the Oregon Solar Energy Conference, or at Solar Power Southeast booth 11.
We ALWAYS look forward to seeing you!
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Industry leader EcoFasten Solar designs, engineers, and manufactures patented, watertight solar roof mounts, rail-less systems, and components. The company provides mounting solutions that are easy to install, cost-effective, rugged in fabrication, and unsurpassed in quality. Comprised of a seasoned and growing team of professionals with talent, ability, and drive, all EcoFasten Solar products are precision-designed with the installer in mind.