A Consumer's Roofing Primer

This little primer tries to give you a sense of what roofing involves and how you can put your own common sense to work when selecting a roofer for anything from a small leak to a new roof.

What challenges every roofer is the geometry of the roof, the roofing material and penetrations.  Each demands a different set of roofing skills, preparation and equipment.

Let's take a quick look at the different geometries, materials, and penetrations your roof may have:

Geometry

Sloped - Most single family homes in DC have sloped, or "peaked", roofs.

Peaked roofs have an overhang to protect the wall below.  The wood and decorative trim on the underside of this overhang is a "soffit" vulnerable to ivy, carpenter bees, rodents and weathering in general.  Good overhead carpentry skills, sheet metal skills and painting skills are essential for repairing soffits.

Gutters are a very important part of these kinds of roofs.  A common problem is that moisture has loosened the gutter fasteners and the gutter begins to warp and sag.  Did you know that an improperly functioning gutter is often the cause of a wet basement?

Curved - Many buildings in DC have at least one section of curved or many-cornered roof.

The roof usually forms a cone on top of a turret or bay.  Some of these roofs are very decorative and remarkably inaccessible.  The challenge here is to construct or repair curves using building materials that by custom are flat and straight — all from a precarious perch.

Sheet - long flat sheets that usually come in big rolls.  The roofing is unrolled on the roof and glued or fused in place.  This material is most common in flat roofs.  Did you know that adding inexpensive foam panels under a reflective flat roof can both increase the pitch (and thereby increase the drainage and decrease the likelihood of leaks) and reduce your heating/air conditioning bill every year for many years to come?

Metal - the edges of thin metal sheets are folded together with watertight seams.  The metal is often steel, but aluminum and copper can be used.  Metal roofing can be used on any flat, sloped or curved roof where water can easily run off.  Metal roofs can last for a very long time.  The trick is to apply a coating every four to six years.

Shingles - individual panels overlap each other like fish scales.  Shingles are commonly glass fibers saturated with asphalt; but, slate, concrete, cedar wood, terracotta, and even metal can be found.  Some shingles, like slate and terracotta, are so durable that the nails holding the shingles in place will rust out long before the shingle shows any signs of wear.  One thing to watch out for is that older buildings may have asbestos shingles that require special environmental precautions.  And, just in case you were wondering, shingles are never used on flat roofs.

Penetrations are things go through the roofing material.  They're unavoidable and the site of most leaks.

Walls - usually a strip of metal called "flashing" is embedded in the wall and dives under the roofing to make a watertight seal with the wall.  Chimneys are a great example.

Roof Seams - a strip of metal flashing is used as a water tight seal where two roofs meet.  Roof seams are most common on sloped roofs.

Utilities - vents for drains, attic fans or vents, and even roof access are unavoidable penetrations.  Every roof has them.  There are all sorts of collars and sleeves designed to keep water from sneaking in around these penetrations — some are better than others.

These tips apply to any roofer you may deal with:

1) Be able to describe what you want.  Roofers build and repair roofs, it's what they do.  But by now you know that involves a lot of different skills and materials.  You can narrow your search to firms that are the right size for your job. Your description of the job gives the roofer an unrehearsed opportunity to show you what they can do given your particular roof geometry, roofing material and kinds of penetrations.  For example, when you know you have a flat roof and the leak is in the top floor bath it's a pretty good bet that a drain vent penetration is leaking — a job that one technician could probably fix in an hour.

2) Remember who pays for a sales staff.  Fact is you will.  A professional sales person/estimator is one of the best paid and most highly skilled people.  They are absolutely essential for large commercial jobs but really contribute little on smaller jobs.  If the roofer doesn't have a sales force, it may take a few extra days to schedule an appointment, postponements are possible and someone may show up in work clothes.  But, there is a definite cost and quality advantage to direct contact with the folks doing the actual work.

3) Insurance, licenses and references matter.  Responsible roofers have them.  Roofing is demanding and dangerous work, if something goes wrong you'll be thankful.

4) Find out who will be doing the actual work.  Many roofers hire subcontractors to do the actual work.  We know.  We got started as a roofing subcontractor.  Some roofers can't tell you who'll be doing the work until the day of the job when they hire day laborers — what does that say about the job quality?

5) Ask what equipment the roofer expects to use.  It doesn't matter if you understand the answer.  Ask if they own or rent the equipment.  You'll quickly get a sense of the roofer's pride in their craftsmanship and if they are committed enough to have their own equipment.  Both are important to you because everyone works better and more efficiently with familiar and well cared for tools.

6) Water is sneaky.  No roofer can guarantee that you won't have any leaks.  Look for realistic claims and precisely what follow-up the roofer plans to do.  Expect the roofer to want to stop by shortly after the first rain.  The reason is that it's easy to check repairs and seams because water will squish out from even the slightest flaw.  It's inconvenient to have someone clambering around on your roof after a rain, but one or more follow-up visits is the hallmark of a good roofer.

7) Tap your own radar.  It may be dirty and heavy work but roofing is a craft.  Done right there is a lot to be proud of.  Skip the discount coupons.  Look for the enthusiasm and pride that money simply can't buy.