Learn how much roofs cost and how roofing contractor come up with their prices

Research roofing prices to install asphalt shingle roofs, flat roofs and metal roofing.

• I got 4 roofing quotes – which one do I choose?
• Why is it that one roofing contractor wants to charge you lets say $7000, while another contractor gave you an estimate of $4000. Does one work for free, or the other just wants to make extra three grand off of you?
• What goes into cost of roof installation and how roofing contractors calculate their roof prices?
• Are you better off paying a premium to have a reputable roofing contractor working on your home, or going with the lowest bidder?

These and many others, are the questions any homeowners asks when it comes time to replace a roof – especially if your roof is leaking and you need to do it fast to prevent further damages. Here we well discuss how roofing contractors come up with their prices, and in part how our roofing calculator works, because it was designed to simulate a “virtual roofing contractor” giving you a roofing estimate to replace your old roof.

This roof prices guide will show you how roofing contractors calculate your roof replacement cost, what goes into price of a roof, as well as provide you a matrix different roofing materials together with average cost per square to install each type of roof. Additionally we will briefly explain the “roof difficulty” concept and describe why a complicated two or three story roof costs 2-3 times more than a simple ranch-house roof.

How contractors calculate roofing prices:

First and foremost there are two distinctly different methods of calculating cost of roof installation. This is also true in other construction trades such as siding, carpentry, etc.

Method one: Materials, Labor, Overhead and Profit (MLOP).

First method deals with cost of all Materials, cost of Labor, Overhead and Profit (MLOP). This is a better method for a large roofing contractor, but may have flows for both contractors and customers.

Main area where mistakes can be made is the cost of labor – which is actually unknown, and is estimated based on previous experience of the contractor. If the job is easy, these labor cost estimates will be more or less accurate. If roof is complicated, there is a good chance the contractor will make mistake estimating labor costs, and you may be overcharged upfront or there contractor will tell you in the middle of the job that he miscalculated the labor and there must be a change order. In reality, unless you are dealing with VERY experienced roof estimator and the company really knows its costs of labor and overheads, MLOP is not the preferred of roof pricing.

Method two: Price per square (1 square = 100 sq. ft.)

Per square pricing is the most popular and i most fair method of estimating roofing prices, for both homeowner and roofing contractor.

I personally always use Per Square pricing, unless the roof is really small or it is all cut-up and consists mainly of detail work. When I price a roof, my “first” concern is not really to make “X” amount of money, but not to loose money on the given roofing job, due to unforeseen  complications. Therefore I first of all try to anticipate and include everything that will be done during a roof installation, and second – if I know there will be unknown amount of extra work, I will always exclude it from the total and price it when we actually know what we deal with. Additionally I would up-charge a roof if I know there will be extra work, but I have no way of knowing how much, until we for example remove the old roof. In some cases I leave it as a separate Item subject to change, depending on how much extra repair work  will have to be done.

Which roof pricing method is more common?

While some roofers have different ways of calculating roof costs, the two roof pricing methods are the most common and most roofers will actually use the Price Per Square method, as for most roofing contractors, roofs have become a commodity, and installation is streamlined. Only complicated roofing projects or specialty roof installation using premium roofing materials will include some type of combination of the above methods of calculating roof costs. Example of such complicated or specialty roofing projects include most Copper / Zinc roof installation, multi-story historical and/or really cut-up colonial homes with towers, valleys, dormers, etc.

Roof Prices:

Bellow we will list average roof pricing, on which our roof calculator is based. These prices are generic and can only be used for reference purposes, as your actual price will differ depending on your geographic location, and the roofing contractor you choose to hire. For example if your roofing contractor is fully licensed and insured, and hire legal workers, your roofing cost will be significantly higher than if you hired uninsured roofer, using illegal labor.

Asphalt Shingles roof prices:

Asphalt shingles is the most common residential roofing material in US and due to lower material prices (as compared to metal roofing, cedar shakes or tile roofs) and high competition, asphalt shingle roof is the least expensive roof option.

Based on our experience and survey of roofing contractors from different regions of continental US, average price per square of Asphalt Shingles Roof is in the range of $250-300. This price is to install a new 30-year dimensional (architectural) shingles on a walkable (3-6 roof pitch) ranch-type house. This price includes a tear-off + disposal of 1 layer of existing shingles, 15 lb. felt underlayment, new pipe flashing for plumbing vents (stink-pipes) and ridge cap, using either special ridge-cap shingles or color-matching three-tab shingles.

Chimney re-flashing, Ice & Water shield, ridge vent, rotten wood replacement, sky-light flashing, etc. are usually extra, and most roofing contractors charge for them “per item” or per linear foot, as is the case with ridge vent and Ice & Water shield.

Average cost to flash a chimney is $300, and should include new counter-flashing. Skylight flashing is about $200.

Ridge vent is $5-7 per linear foot. Ice & Water shield is $4-6+ per linear foot, depending on the type / brand of Ice & Water product used. Smooth-faced Grace I&W shield is the most expensive type and is rarely used, while a granular surface I&W shield is the least expensive and most common.

Ice & Water barrier is required by building code in most areas with significant snow falls – northern US and Canada – while is optional in most of southern US. If your building code does not require use of I&W barrier, I’d recommend not using it as it prevents roof deck from “breathing”, consequently shortening the life of your roof deck.

Average cost-per-square for an asphalt shingle roof will vary greatly based on where you live. The same roof in Metro Boston, MA area will cost almost double of that, somewhere in rural Alabama or in now-struggling metro Detroit area.  Average cost of roofing square in Massachusetts ranges from $375 – $425 per square. Basically, roofing costs are directly related to the cost of living in your area.

Metal Roofing Prices:

Metal roofing is an excellent choice to solve your roofing problems for a VERY long time, and most metal roofs are considered life-time roofing material. Metal roofs offer long-lasting protection, reduction in energy costs (as most metal roofs are in fact cool roofs, and qualify for $1500 federal tax credit), and when properly installed, metal roofs eliminate / solve most roof leak issues such as Ice Dams. However, metal roofs cost significantly more than conventional asphalt shingles.

Since there are many types of metal roofs, from a multitude of metal roofing manufacturers, I will concentrate on three most common types: Standing Seam Metal Roofs, Exposed Fasteners Metal Panels (corrugated steel, R-panel, V5-crimp, etc.) and Interlocking Metal Shingles.

As in case with asphalt shingles, our average metal roof prices is based upon a walkable, ranch-type house with 1 layer of roof tear-off and disposal and normal penetration flashing. However in case of metal roofing, things like Ice & Water and ridge vent installation, are included in price. Other things that should be included are: Snow Guards in the northern US / Canada, synthetic underlayment (if your roofing contractor proposes to use Felt / tar-paper with a metal roof, kick them out of the house tell them to never call you again). A complete chimney re-flashing, using color-matching flashing and counter-flashing, as well as custom-fabricated skylight flashing must be installed, though can be charged for separately.

Cost of Standing Seam Metal Roof:

While vertical panels standing seam roof may seem easy to install, it is only on roofs such as straight gable with with minimal number of penetrations. As the roof gets more complicated, installation of Standing Seam roof becomes MUCH more complicated, as compared to interlocking shingles. For example, a non-walkable (9-12 roof pitch) hip-roof is VERY difficult to nearly impossible to install, without use of a hydraulic platform lift, as the installer has nowhere to hook his hook-latter, and it is also impossible to install roof jacks without penetrating roof panels. Therefore, a relatively difficult roof will cost dramatically more to install standing seam on, vs. metal shingles.

The cost to install the metal roof in a picture above, was about $1300 per square.

Cost of Steel Standing Seam ranges from $800-1000 for a simple gable roof.

As soon as the roof becomes more complicated, standing metal roof price goes up to $1200-1500 range. Aluminum standing seam will add about $75-100 per square to account for additional roof materials cost of aluminum vs. steel. Sky-light and chimney flashing on a standing seam roof will cost an average of $400 per unit, vs. $300 per unit on a metal shingles roof, as they are much more involved and complicated.

Please note that unlike metal shingles, Standing Seam metal roofs should not be installed over asphalt shingles, as the shingles profile will punch through the vertical panels, creating horizontal lines every 5 inches – this is a so called telegraphing effect of metal roofing.

Metal shingles roof prices:

Metal roofing shingles will cost a little less to install on a simple, as compared to standing seam. On a complicated roof, metal shingles will be significantly CHEAPER to install, vs. standing seam roof prices, as metal shingles design  allows to install roof-jacks (roof staging) and roof installers can easily move around the roof, without using a lift. It is also much easier to install and remove fall-protection / safety harnesses equipment on a metal shingles roof.

Cost to install a steel shingles roof, on a simple gable roof: $775-850 per square.

Cost to install an aluminum shingles roof, on a simple gable roof: $875-950 per square.

A more complicated roof will increase in price by $100-200 per square (compared to an increase of $350-500 in case of standing seam roofing).

Exposed fasteners / Corrugated Steel roofing prices:

Exposed fastener steel roofing panels are the least expensive option in the world of metal roofing, but is also the worst metal roof in terms of quality. These type of roofing is usually made of cheap 29 ga. steel, coated with cheap acrylic paint (compared to a minimum of 26 ga. steel and Kynar 500 metal roof coating for steel standing seam, and .032″ aluminum + Kynar 500 for alum. standing seam roofs). the difference will start to show itself in about 10 years, as the paint may / will begin to fade, peel and chip of the metal, and first signs of rust stains will begin to appear.

Exposed fastener roof will also have to be “re-fastened” around the 10-year mark, as rubber / neoprene washers will dry out, and water will start sipping in.

Cost of exposed fastener metal roofing panels ranges at $500-700 per square for a simple gable roof.

Exposed fastener metal roofs SHOULD NOT be installed on complicated roofs or within 1 mile form salt water shore line. As for complicated roofs, exposed fastener metal panel roofs lack proper flashing details, and re-fastening them after 10 years will be very costly and dangerous.

As far as salt-water environment, any steel roof should not be installed within 1 mile of the coast as corrosion will eat such roof in a very short period of time. Aluminum is the best choice of metal roof to be installed near the water.

Flat Roof Prices:

There are 3 or 4 major types of flat roof materials that you can find on the market today. Additionally, there is a HUGE difference between commercial and residential flat roofing. Commercial roofing contractors will usually not work with a homeowner, unless your roof size is over 3000 square feet, or the contractor is really desperate for work. In second case you should be worried as to why the contractor does not have enough work – is is just the bad economic situation or poor workmanship?

As for residential roofing contractors specializing in flat roofs – here you have even fewer options is it is very difficult to find a roofer that will know low-slope and flat roofing. Most residential roofers install EPDM rubber roof – a flat roofing material which any contractor can buy without any approval/certification by the manufacturer. Rubber roofs also do not require any special tools or equipment to install – a few simple tools all costing under $300 is enough to start installing and repairing rubber roofs, and hordes of untrained and inexperienced roofers claim to be “flat roof specialists”. Such rubber roof installations all too often result in roof leaks and sometimes even complete blow-offs:

Other flat roofing materials commonly installed today are PVC Roofing (and in rare cases TPO roofs), modified bitumen (torch down, mop-down and peel-and-stick type application), and in very rare cases, tar and gravel roofs. Although in commercial roofing, TPO roofs outsell PVC due to price difference, in reality, you should be aware of benefits that more expensive PVC roofs offer and potential massive TPO roof failures that may dramatically change the reality of flat roof market in the near future.

Cost of residential flat roofs:

EPDM Rubber Roofing Prices – EPDM rubber roofs on average are installed for about $450-500 per square, including 1/2 inch wood fiber board and typical flashing. If you are having a rubber roof installed, you should make sure that your roofing roofing contractor is certified by a major EPDM manufacturer (Firestone or Carlisle – Versico, RPI and other smaller brand are not manufacturers, but rather private labels and do not certify their contractors). Also make sure that contractor will use Peel and Stick (quick-apply, etc.) EPDM roof flashing and seam / cover tape:

• 3″ EPDM seam tape
• 6″ EPDM cover tape all around roof perimeter and drip edge
• Preferably, 6″ EPDM cover tape over all seams
• Lap sealant along all seam overlaps
• aluminum termination bar with masonry anchors at all chimney and roof to wall flashing detail (unless equal termination method is used)

If your roofing contractor proposes to use “black rubber glue” or splice adhesive, kick them out of your house immediately! Black rubber glue breaks down twice as fast as peel-and-stick primer, and is much cheaper. Contractors that do use the splice adhesive either don’t know what they are doing or want to sell you the cheapest roof possible!

Price to install modified bitumen roof – There are too many type of Mod. Bit. and at least 4 ways to install it, and it is too much to cover under one general purpose roof pricing guide.

In general Modified Bitumen is a torch-down installation and contractors installing modified bitumen are usually more knowledgeable than those installing rubber roofs. Still, you should definitely check that your roofer has full roofing liability insurance as it is very easy to burn down the hows when using the torch, and many roofers will not carry the roofing liability at all due to very high cost. I would call the insurance agent / insurance company instead of just trusting the “certificate” which can easily be expired.

Cost to install a quality APP modified bitumen roof should be around $500-600 per square.

Prices to install PVC Roof – An average PVC roof installation will cost between $650 and $900 per square depending on the roofing material you are using and difficulty of your roof. Nominal thickness of a PVC roof is either 45 or 50 mil, and you can go as hig as 80 mil, as well as specialty flat roofing products designed for flat roof decks as well as chemically resistant PVC roofs for restaurants and industrial roofing. We recommend you research flat roof prices to install IB PVC roofs, at CoolFlatRoof.com – you can also use CoolFlatRoof’s flat roofing price calculator to estimate roof cost in Massachusetts. You can also find a local IB PVC roofing contractors listed at their green construction directory.

Prices to install Tar and Gravel Flat roof – Tar and grave roofs are really outdated, and although some old-timers who still have a hot tar/asphalt kettle, will swear that their tar roofs have been in service for 50 years, face the reality – tar roofing is nearly extinct and there is a good reason for it – it is dangerous, inefficient, bad for your health and there are very few roofers out there who still know how to do it.

Average cost to install a tar and grave roof is about $550-600 and will vary greatly depending on current oil prices.

Flat roof tear-off / removal prices:

Price of flat roof tear of is usually determined by the number of roof layers that you have on the roof, weight of the roof and local dump / recycling cost. In New England, it is normal to pay at least $80-90 per ton (2000 lb.) to dump construction waste, whereas somewhere in the mid-west, it will be $10-15 per ton. Old tar and grave roof can weight anywhere from 400 to 800 lbs. per square, plus the cost to remove it. So you may have to pay on average a $100-150/square, for the first layer and another $50-75/square for each additional layer of old roofing tear-off.

Additional up-charges for more-difficult roofs:

Roofing contractors will generally charge more for following items or in following situations:

• Second or third story roof.
• More than one layer of roof tear-off / disposal.
• Tearing off cedar shingles, slate or tile roofs on sloped roofs and tar+grave / bur roofing materials on a flat roof.
• Difficult customer – the so called PITA up-charge (Pain In The A$$).
• Difficult roof access.
• Small roof / complicated roof.
• Steep roof.

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