What are "green" alternatives to replacing an old shingle home roof?

November 8, 2006 9:39 PM

What are some "green" alternatives when replacing an old shingle home roof (in New England)?

The roof of my parent's Boston-area home needs replacing (ie, to be reshingled). The house is a cape-style originally built in the 1940s (?), and doesn't currently have any radical/alternative design features. My dad, acting upon his new Thomas Friedman reading, "Inconvenient Truth" watching, energy-bill climbing environmental ethic is interested in finding out what sustainable alternatives (or modifications/additions) to traditional shingles are out there.

What's the current thinking on photovoltaics (solar panels) on residential projects? What about solar water heating? Rain collection? How might this options play out financially, both in initial cost and longer-term returns? Does anyone have experience with these types of projects (or architects/contractors with green expertise in the Boston area)?

posted by chefscotticus to Home & Garden (13 answers total)

Remember it's Reduce, Reuse, Recycle in that order. Using something like tile that will last for decade upon decade after you would have to replace asphalt many times over is a great way to reduce. The cost is more initially, obviously, but far less than replacing shingles 5 times in the 150 years that they will last.

So, you could combine tile with solar panels and collect rainwater.
posted by Pollomacho at 10:41 PM on November 8, 2006

Oh, I thought of one more thing, you could sprout moss on the tiles which will reduce the runoff and also filter what there is a bit. It's easy to start, just find some existing moss on a wall, path or rock and mix it with some buttermilk. Resisting the urge to drink it, you just pour the liquid where you want it.
posted by Pollomacho at 12:57 AM on November 9, 2006

Generally, the limitations on available sunlight in far northern climates, coupled with the colder winter temperatures seen there, mean that solar projects of any type are less likely to be a financial success, than they are in Arizona or Florida. And even in those sunny climates, photovoltaic projects and solar water heating are long payback projects. That's one reason that as of 2004, even with various state by state government and utility incentives for photovoltaic projects, only about 10 Megawatts of generation capacity had been installed in the 6 states of the New England region, with a total population of 14 million. Even with tax breaks and incentives, photovoltaics are a poor investment financially.

Another thing to consider is that roofing material choices can affect home insurance rates, and the desirability of the home at resale time, as will externally visible solar project collectors of any type. Some prospective buyers will be concerned about maintenance and operation of solar systems, and may not be willing to value them at all in their offering price. People in the neighborhood may also have a say in external appearance items, like roofing and visible solar equipment, through homeowner associations, restrictive covenants or city ordinances. So, your parents would want to check those issues before spending money on a roofing or solar project they'd be responsible to modify on appearance or materials issues later.

That said, they may want to look into Stone Coated Steel Roofing, which is a high performance coated metal roof that can offer significant wind and fire protection, and very long life. Its appearance is generally a pretty conservative granite grey, coming from the stone chips used in its coating process, but there are some color alternatives available. The "green" element of this roofing choice comes in the "Reduce" element, as a steel roof can out last 3 or 4 shingle roofing jobs, making for less landfill material by far, over the life of the steel roof.
posted by paulsc at 4:02 AM on November 9, 2006

Not to derail here - but I wonder if anyone has done a study to find out how much it would cost for the American government to outfit every home in the U.S. with solar panels and how much that would lower our dependence on foreign energy. I can't imagine it would cost more than we are spending on the Iraq war every month.

As far as tile roofing being more eco-friendly than shingles - do we have any information on how much fossil fuel is expended to make one shingle as opposed to one tile?
posted by any major dude at 5:45 AM on November 9, 2006

Steel roofing is probably the best alternative but it may depend on local building codes. Generally tile is very heavy and can only be used on a roof designed to hold that extra weight. You can't just throw on tile to the roof of any wood-frame house.

People have been using solar hot-water heating systems in Wisconsin since the 70s. Photovoltaics can easily be retrofitted depending on whether he doesn't have trees in the way. But again, check local building codes which may prohibit such things.
posted by JJ86 at 6:17 AM on November 9, 2006

Standing seam metal roofs have gotten much cheaper and last practically forever. I think they're also eligible for the Federal Energy Tax credit.
posted by electroboy at 6:30 AM on November 9, 2006

The Return of the Sod Roof
posted by caddis at 6:43 AM on November 9, 2006

A house on my block (in Cambridge) has recently installed rubber slate tiles. They look fairly natural (I've heard people ask the installers if they're real slate while out on my walks), and are now being made from recycled materials. See this article via This Old House. They may not be the most "green" alternative, but for a lot of homes in the Boston/Cambridge area, historical match is a consideration if not a requirement.

If your dad's place doesn't suffer from those requirements, I say go with sod if possible. And grow vegetables up there. In New England, though, a steep pitched roof is a better option because of snow and may rule out sod (I don't know what the angle of tolerance is for sod..).
posted by cocoagirl at 7:11 AM on November 9, 2006

Could look into recycled shingles.
posted by DenOfSizer at 7:50 AM on November 9, 2006

JJ86 writes "Steel roofing is probably the best alternative but it may depend on local building codes. Generally tile is very heavy and can only be used on a roof designed to hold that extra weight. You can't just throw on tile to the roof of any wood-frame house."

Sheet metal roofing (less than a pound per sq ft) weighs less than ashphalt shingles (2-4 pounds per sq ft) and holds less snow if you've got any kind of slope. If your roof is in sound condition and you only have a single layer of shingles you can sometimes apply the metal directly over the shingles (over a layer of tarpaper) saving the labour of a tear off.

It's the best choice for a green alternative to ashphalt shingles as it

1. lasts a long time (30-50 yeats minimum)
2. is 99.5% recyclable at EOL
3. has lower embodied energy than tile and most slate
4. is the best surface for rain water collection
5. on simple roofs can be installed by any able bodied person

posted by Mitheral at 8:06 AM on November 9, 2006

paulsc hit the points about PV pretty well, but I'd just add that if you're determined to throw your money away on a PV system (even here in MN, where our solar resource is comparable to parts of Florida and Texas, it's 15-20 years to payback), do everything you can to reduce your electric consumption first. Get below 10-15 kWh/day before you start thinking about making your own energy; the payback from improving your efficiency is faster and if you decide to install the PV, you won't need to install as much to get a bigger percentage of your usage.
posted by nickmark at 9:00 AM on November 9, 2006

Slate is likely to give you the longest life. Slate roofs installed in the 1850s are still holding up today with a little maintenance. The biggest problem with them is that they were installed with iron nails that rust through, letting the tile slide off. A new slate roof today would be installed with stainless steel or copper nails that resist corrosion, so it is likely to last for 200 years or more -- nobody really knows. It probably is the costliest option, short of photovoltaic panels, but has a very low lifecycle cost, adds fire protection, and won't rot. The drawback is that it's heavy, so structural support needs to be investigated. There are also concrete roofing tiles with similar properties.
posted by beagle at 9:30 AM on November 9, 2006

Mitheral, I wasn't saying that steel was heavier than asphalt shingles, I was saying clay tile was heavier than asphalt. The same goes for slate as well. Metal roofing is a great alternative and comes in a huge variety of styles. The best looking IMHO are enamel metal tiles. Depending on where you live, some neighborhood associations or cities don't allow sheet metal roofing.
posted by JJ86 at 11:10 AM on November 10, 2006