How to Calculate the Roof Area

Posted by:  Jeff Ahbe

When you are about to start your Denver roofing project, you will need to calculate total roofing materials needed for the job.  To get this amount, you need to estimate the total surface area of your roof so you know how much to order.  When calculating your surface area, the easiest way to do this is actually measuring your roof.  When doing so, round up to the nearest foot to make your calculations easy and to ensure you order enough! 

It is easy to calculate when you think of your roof as a flat rectangular surface.  If measuring a gable roof, find the area of a rectangle, multiply the length times the width.  Measure along the ridge or eaves to find the length and from the ridge to the eaves to find your width.  If you multiply the two numbers together you'll get the square footage of one side of your roof.

Complicated Roof Measurements

If you have a section of your roofing system that is more complicated that the basic gable roof, it is easier to divide your roof into triangles.  To find the square footage of a triangle, multiply the height by the width and divide by two.  Once you figure the area of your triangles, simply add them up to get your roofs area.

If your roof is inaccessible or hard to maneuver you will need to make your measurements from the ground.  Measure the roof as if its edges were projected on the ground and then correct for the amount of slope in the roof by using the area/rake conversion chart to the right.  Make sure to calculate the roof overhangs, don't just measure wall to wall of your home. It is easier to draw the roof outline on paper and add the ridge, dormers, chimneys or porch to your figures.

Once you have a proper outline, take the following steps to correctly calculate your roofs area:

Waterproofing Underlayment

A roof depends on gravity to make water run down an doff, but when held back by ice, or during intense driving rain, water can work its way up and under even properly installed shingles. Because normal felt underlayment is not completely waterproof, especially around nail holes, water can work its way in. Highlands Ranch roofers say, for those who experience harsh winters it's reassureing to know you can install additional insurance afainst water dmage.

Waterproof shingle underlayment is a special material mafe of asphalt and elastic polumers designed to adhere tightly to roof sheathing and around the shanks of nails driven through it. This self-sealing attribute ensures that water cannot fet past it, even where you drive a nail.

Install the underlayment along those areas where ice dams and driving rain can create a problem, or where water tends to accumulate along the eaves, around skilights in calleys, in saddles or on low pitched roofs. Noramal felt underlayment should still be installed in non-critical areas, and metal flashing shoulf still be used as per ordinary roof

Roofing with Slate

Roofing with slate is very expensive. Actually slate roofing is one of the most expensive roofing material options available on the market. Even when you consider the long lasting lifespan of slate, the price is still out of reach for most homeowners. If you're looking to install a new roof Denver contractors don't always suggest these long lasting roofs. The reason for choosing slate roofing materials for your home is not affordability but aesthetics. Slate roofing materials give a home a chic yet rugged look that many modern style homes look great with. Slate can be places over a layer of composition shingles if the slope of the roof is 4-15+ is a structural engineer signs off on the roof framing sturdiness.

Slating a roof takes a considerable amount of skill; however, some skilled do-it-yourself enthusiasts are capable of the project. Slating requires quite a few specialized tools that most people do not have in their backyard sheds and these tools are fairly costly. Sometimes it is more cost effective to pay a professional to take on the task than to invest in the tools required for the job.

Slate is available in a huge variety of grades and thicknesses, so ask a salesman how long your selection is expected to last. This material also comes in many colors ranging from grays and greens to purples and reds. Some of these colors will fade after years of exposure. Slate can also be purchased in smooth or rough surfaces. Different colors and textures may be used on a single roof, but Denver roofing professionals say it can be very difficult to make pattern with the colors you choose to turn out in a pleasing design.

Installing Metal Roofing

Metal roofing has recently gained in popularity. Metal roofing is most commonly found on commercial buildings and older homes, but can also be found on residential new builds. Metal is a great material for roofing because of its longevity and low cost.

Standing-seam panel roofing is the most common type of metal roofing for residential builds. Panels usually run vertically and are made of aluminum or galvanized steel, but in some cases they are made from zinc and aluminum-coated steel. Since the panels are painted they offer many different color options. Metal roofing is ideal for restoring older homes that were originally fitted with metal roofs.

Metal roofing is a light material suitable for covering older roofs and could even be layered over composition shingles (depending on local codes). For roofs that have irregularities, narrow, texture and dull-finish panels are the best choice. Metal roofing can cover a roof with a slope of 3 in 13. Other metal roof Denver residents sometimes choose can work on roofs with slopes as sloght as 1/4' in 12. However, the experience and special equipment needed will required a skilled contractor for this metal roofing installation.

Installing metal roofing is a process that involves laying 12-16.5 inch panels and correctly joining them at the seams, wall flashing, valleys and ridges. The panels are pre-cut to the exact length ordered up to 40 feet long. Metal roofing can be applied to plywood decking with an underlayment of 30 pound felt. Laying and joining the panels is not difficult, but handling eaves, rakes, edges, wall flashing and ridges require an experienced roofer.