Keeping a Lid on Roofing Costs Can Be Sticky : Materials: None of the options are cheap, but some offer economy, safety and esthetics.

Expense generally is the first, second and third thing on a homeowner’s mind when the subject of reroofing comes up. But there are other concerns: Asphalt or wood shingles? Concrete or clay tile? How fireproof is it?

Herein, some answers:

Cost

Reroofing isn’t cheap; $1.50 a square foot is about the bottom line for a job on a flat roof, using the least expensive type of rolled roofing and not involving removal of the old roofing material. That’s $1,500 for a relatively small, 1,000-square-foot home.

It goes up from there.

Labor costs will represent 50% to 75% of most jobs, contractors say--less for recovering existing roofing material and more for complete reroofing involving removal and disposal of the old roofing.

Costs for the roofing material itself range from about $20 to $300 or more per 100 square feet--roofing is generally sold by the “square,” each square containing enough material to cover 100 square feet. Nails, mastic, special trim pieces for edges and ridgelines, and metal parts--drip caps for the eaves, flashing for chimneys and vent pipes and valleys for the V-shaped junctions of two sloped roofs--can boost the materials cost by 10% to 30%.

And no matter how much you pay for the roofing material, a roof ultimately is only as good as its underlying material--the black, asphalt-impregnated paper that is rolled out and nailed down to the wooden decking before the roofing material is applied. This underlayment is classified by its weight per 100 square feet--the lighter the weight, the thinner and less expensive the material. A 400-square-foot roll of 15-pound paper will cost about $10, while 60-pound paper can run $15 or so for a 100-square foot roll.

Prices from two local roofing material companies, Ford Wholesale Co. in Stanton and Pacific Supply Co. in Orange, illustrate the range of prices and materials homeowners must deal with when selecting roofing:

Rolled mineral roofing for flat roofs, generally sold in 90-pound, 100-square-foot rolls, costs about $12 a roll. A new type of rolled roofing, called a single-ply system because it doesn’t require multiple layers of hot tar and felt paper under the mineral-coated roofing material, runs about $20 per roll.

Composition shingles--usually fiberglass and asphalt--are used on most homes built before 1960 and still are in wide use today. The National Roofing Contractors Assn. estimates they cover 80% of the homes in the country. The percentage is lower in Orange County, where wood shingles and tile roofs have been popular for years, but roofing material suppliers in the North and Central County say 50% to 75% of their sales still are composition shingles. They can cost $20 to $75 per square for the most readily available types. Special colors or shapes can add to that, appreciably.

Wood shingles can run from as little as $125 a square to about $200. Some hand-split shakes, and shakes or shingles in fancy shapes, cost even more.

Concrete tiles, often made to look like Spanish or mission-style tile, run from $60 to $100 a square. Because they are heavy, they often require extensive--and expensive--strengthening of the roof joists before they can be installed.

Clay tiles, in the most common Spanish, Mediterranean and mission styles and colors, run $85 to $125 per square.

New lightweight tiles, made of concrete and wood fibers, provide a close replica of wood shakes and clay tiles, come in varied looks, shapes and styles and often carry 50-year warranties. Prices start at about $125 a square but quickly escalate, topping out at about $300 a square.

Fireproofing

Clay and concrete don’t burn, but the roofing paper and wood under them can. Thus, no roof is completely fireproof.

The proper term is fire-resistant. Roofing material is sold under four general classifications, based on Underwriters Laboratory tests of the ability of complete roofing systems--decking, underlayment and roofing material--to withstand fire from outside sources (burning branches, fireplace embers, fireworks):

Class A, or highly fire resistant--the best there is. Most fiberglass-composition shingles, clay and concrete tiles and lightweight tiles come in Class A ratings.

Class B. Best grade for a wood shingle.

Class C. Lowest rating, usually for wood shingles or organic composition shingles made of asphalt-impregnated wood fibers.

Unclassified. You’re really playing with fire. Not allowed on residences in Orange County.