And now for the rest of the story on roofs

Last week we looked at several roofing products available in today's market — steel, cedar and composition products. Now for the rest of the list and prices.

Torchdown

Torchdown is a single-ply low- or no-pitch roofing that has almost completely replaced the ubiquitous "hot tar" roofing materials in residential construction. Torchdown is a pliable material rolled out over a "base sheet"; the seams are heated with a torch, melting together. There have been no widespread problems with torchdown, although it does require periodic application of an aluminized UV reflectent coating to achieve best life and preserve manufacturer warranty.

More recently, granulized torchdown has appeared en masse, negating the need for the UV coating. The granules protect the tars beneath, similar to how a composition shingle is protected from the sun by granules. Torchdown with painted-on protection or granules, has a life limit of 12 to 18 years and is expressly not designed for foot traffic.

Rubberized PVC

Rubberized PVC roofing materials are used for roof decks or flat roofs with traffic. Roof decks are not to be confused with decks that also serve as roofs. Roof decks are roofs first, decks second.

Deck-covering materials such as hot-seamed vinyl or elastomeric decking are better and more attractive walking surfaces, but inferior roofing products. I have heard of no problems with these rubberized PVC roofing materials, and many come with a lifetime warranty. Some PVC products may be slippery when wet.

Slate

Slate is probably the most beautiful product you could put over a home. Most of us cannot afford it, not just because the material is so expensive, but also because of the need for copper or stainless-steel nails, flashings and accessories. Slate cannot ever be walked on. It is very brittle.

Moss may even make the roof look better and can't really hurt the stone. Occasionally a piece will need replaced, but that's about all that's needed for at least 100 years of roof life.

Clay

Traditional clay tile looks fabulous and lasts a long time, but again, it can be brittle. A time-proven product and expensive, it is best suited only for specific architectural objectives.

Concrete

Concrete tile generally will last 50 years and up. Ultimate life at this point is unknown, because the product has not been in service on a large scale long enough to gauge accurately. As with any tile, it is heavy and is used successfully in high-wind areas.

Concrete tiles come in many grades, colors and styles. Challenges related to installation in the past have made leakage at valleys in heavily treed spots a possibility, although the techniques for most installations have changed.

When retrofitting to any tile product, consider whether your roof is structurally capable to carry the extra weight.

Aluminum

Aluminum roofing is a rare material. In fact, I have not actually seen such a roof up close. Sources tell me it is promising, but the jury is still out.

Copper

Copper roofing is used mainly for accents and architectural detailing, although occasionally an entire roof may done with it. Copper takes on different hues in differing light and as it ages. Copper is one of the few roof systems you can go out and shine.

New arrivals

New materials such as plastic, fiberglass, fiber-cement and other mixes arrive on the scene at every home show, claiming to be the greatest thing to happen to roofing since the shingle. But the plain truth is, most are junk.

I'm always willing to be convinced and educated, but the long-term industry record of failure is abysmal, not only by lawsuit, but by anecdote and experience of many. Some materials become brittle or melt, some may absorb moisture, swell and grow moss, others might delaminate. Some materials have even been known to twist, pulling the securing nails and falling off the roof.

What works in Arlington, Texas, or Arlington, Va., doesn't necessarily work in Arlington, Wash. It takes many years of experience to truly test a product, as the long list of defeated siding and roofing manufacturers can attest. Caveat emptor.

In speaking to roofers and roof suppliers of all stripes, many were struck by the noticeable increase in quality of cedar shakes recently (particularly those from Canada), as well as the needed improvements the cedar industry has taken related to producing and treating these materials.

At least two mills are currently offering written warranties on their cedar shakes, an unheard of concept until recently.

To put it all in perspective, one man selling an expensive roofing product could not help himself but to point out the undeniable "bang for the buck" in the humble 20-year composition shingle that routinely lasts 25 years.

The consensus best compromise on good looks, cost, roof life is hands-down the 25-year dimensional composition, the very reason so many builders use it today.

Darrell Hay answers readers' questions. Call 206-464-8514 to record your question. Or e-mail dhay@seattletimes.com. Sorry, no personal replies.