Top 3 Roofers in Alexandria, VA

Porch Pro Headshot Champion Home Improvements, LLC.
Update your home with new windows by calling the specialists at Champion Home Improvements, LLC., who have been awarded 4-stars by residents in Aspen Hill, MD.
4920 Niagara Rd Ste 207, College Park, MD
Porch Pro Headshot Improving Construction, LLC
100% response rate
We are a Roof, Kitchen & Bathroom Remodeling Company. We guarantee high-quality work for each & every project.
7434 Ardglass Dr, Lorton, VA
Porch Pro Headshot Style Installations Inc.
When it comes to Roofing Contractors and Roofing Services, no one compares to Style Installations Inc. With years of combined experience, Style Installations Inc. has worked hard to build the trust of our clients in Falls Church, Fairfax, Dale City and beyond. Visit our website to learn more. Or bet...Read more about Style Installations Inc.
Serves Alexandria, Virginia

More Roofers in Alexandria, VA

Porch Pro Headshot Thompson Creek Window Company
Roofers
4200 Parliament Pl Ste 600, Lanham, MD
(5,901)
For quality vinyl siding, be sure to call the experts at Thompson Creek Window Company in the Annapolis, MD area, awarded a high A+ rating (as of January 2018) by Better Business Bureau.
4200 Parliament Pl Ste 600, Lanham, MD
For quality vinyl siding, be sure to call the experts at Thompson Creek Window Company in the Annapolis, MD area, awarded a high A+ rating (as of January 2018) by Better Business Bureau.
Porch Pro Headshot NOVA Exteriors, Inc
Roofers
5568 General Washington Dr Ste A208A, Alexandria, VA
(1,620)
We strive to offer high quality products and installation at a fair and reasonable price.
5568 General Washington Dr Ste A208A, Alexandria, VA
We strive to offer high quality products and installation at a fair and reasonable price.
Porch Pro Headshot CARE Contracting
Roofers
14908 Ingalls Ct, Leesburg, VA
(388)
"I am a Realtor that refers Chris Bazow from Window Source of Virginia. I have sent him to numerous clients. Every single one has said that not only has his pricing been excellent (better than other window/door companies), but the service and installation have been superb. Don't waste your time w...Read more about CARE Contracting
14908 Ingalls Ct, Leesburg, VA
"I am a Realtor that refers Chris Bazow from Window Source of Virginia. I have sent him to numerous clients. Every single one has said that not only has his pricing been excellent (better than other window/door companies), but the service and installation have been superb. Don't waste your time w...Read more about CARE Contracting
Porch Pro Headshot Hernandez Roofing Pros
Roofers
4502 Grenoble Ct, Rockville, MD
(147)
Hernandez Roofing Pros is a family owned and operated business with over 10 years of experience. Hernandez Roofing Pros takes pride of there quality of work and work hard every day to bring homeowners best service and best products up to date. We offer great warranties on products and installation...Read more about Hernandez Roofing Pros
4502 Grenoble Ct, Rockville, MD
Hernandez Roofing Pros is a family owned and operated business with over 10 years of experience. Hernandez Roofing Pros takes pride of there quality of work and work hard every day to bring homeowners best service and best products up to date. We offer great warranties on products and installation...Read more about Hernandez Roofing Pros
Porch Pro Headshot Nation's Choice Windows
Roofers
6094 Franconia Rd Ste D, Alexandria, VA
(132)
We are proud to say that Transnational Corporation has been Northern Virginia's premier contractor for over 27 years! Our love for our work, attention to detail, and highest quality products keep our customers delighted time after time! As a trusted member of the community, we look forward to assist...Read more about Nation's Choice Windows
6094 Franconia Rd Ste D, Alexandria, VA
We are proud to say that Transnational Corporation has been Northern Virginia's premier contractor for over 27 years! Our love for our work, attention to detail, and highest quality products keep our customers delighted time after time! As a trusted member of the community, we look forward to assist...Read more about Nation's Choice Windows
Porch Pro Headshot Home Improvement LLc
Roofers
3140 Annandale Rd, Falls Church, VA
(42)
"Definitely would recommend Home Improvement LLC for your home repairs. Garage drywall with mold repaired. They responded quickly to my request for an estimate. The guys were so polite and efficient in their work. Very professional and it was evident that they took pride in their work. Keeping ...Read more about Home Improvement LLc
3140 Annandale Rd, Falls Church, VA
"Definitely would recommend Home Improvement LLC for your home repairs. Garage drywall with mold repaired. They responded quickly to my request for an estimate. The guys were so polite and efficient in their work. Very professional and it was evident that they took pride in their work. Keeping ...Read more about Home Improvement LLc
Porch Pro Headshot Virginia Craftsman Services LLC
Roofers
14605 Vint Hill Rd, Nokesville, VA
(39)
At Virginia Craftsman Services, LLC, we are committed to providing quality repairs, constructing, and exterior maintenance. We provide interior and exterior services, including roofing, gutters, siding, windows, kitchen and bathroom remodeling, painting, framing, drywall, and doors. We are a family ...Read more about Virginia Craftsman Services LLC
14605 Vint Hill Rd, Nokesville, VA
At Virginia Craftsman Services, LLC, we are committed to providing quality repairs, constructing, and exterior maintenance. We provide interior and exterior services, including roofing, gutters, siding, windows, kitchen and bathroom remodeling, painting, framing, drywall, and doors. We are a family ...Read more about Virginia Craftsman Services LLC

Frequently asked questions about roofers

In most cases, you can install metal roofing over shingles. There are some exceptions to this, largely depending on how damaged the roof is. Your roofer will ensure that your home can handle a metal roof structurally and that any issues present won’t be exacerbated. Metal is very strong, but also very light compared to other roofing options, such as asphalt. It can be installed directly overtop the existing shingles, meaning you’re going to save a lot of money leaving them in place. Because metal is light, it won’t significantly increase the load for your home to bear. These roofs last a long time, they reflect heat rather than absorb it, and can withstand whatever the weather throws at them.

When it comes to installation, a quick “roofers near me” search can find you a professional. The basic idea is that you are screwing the metal over top of your existing shingles. Begin with getting a precise measurement of the surface you’re covering. Valleys, dormers, and chimneys will affect how much metal you need. You’ll start with laying roofing felt over the entire roof. You want your felt to be straight and square. Some people use wood strips to assist them. Any seams where water can get into will require flashing. From here, put the panels in place. Keep them straight and symmetrical, and apply this to the screws as well. You’re going to have to cut the valleys by hand, so be precise in your measurements.

Use rubber or foam closure strips for any overlaps. Get some that match the shape and color of your roof. These prevent water damage. You also have the option of attaching rubber strips for plumbing vents. Once finished, attach the ridge cap. This gives the roof closure and prevents leaking. You can also use a mesh to create a ridge vent that allows airflow.

There are a number of options you can use when it comes to roof installation.

Shingles (asphalt, fiberglass, and composite) – Asphalt is the most common roofing you’ll see on modern homes. It’s relatively cheap compared to other options and can last up to 30 years. They come in a variety of color options, which are prone to fading over years of sun exposure. You can opt for architectural shingles, which are thicker and more weather resistant. You can also do three-tab shingles, which are quicker to install but are prone to wind damage.

Metal – This style of roofing has been around for longer than most people realize, and is gaining popularity. Zinc and aluminum are cheap, beautiful, and require very little maintenance. Metal roofing is highly durable and will last a long time. Improper installation will cause problems, and you may need soundproofing for the noise it can generate in a storm.

Wood – Wooden roofing can make for a cozy-looking home, and it lasts longer than shingles. While wood is beautiful, it comes with a higher maintenance cost, especially in areas prone to fire (where you’d need to specially treat the roof). Wood is best used in dry climates, as water, mildew, and mold are a problem for wood.

Clay – Clay may last for an entire lifetime and is extremely fire and wind-resistant. It’s been used for over 5000 years around the world and is still being used today. Clay doesn’t have many color options, and it can be heavy. It also may require specialized labor to install. It's great at regulating the temperature within a home.

Slate – Slate is a material that will last. It may not need replacing for nearly 200 years, is completely fireproof, and withstands winds and temperature extremes. Slate is expensive and heavy, much like clay, and may require extra structural support. Unlike clay, it has a wider variety of color options.

TPO stands for Thermoplastic Polyolefin. It’s a mostly recycled rubber material sold in rolls, which are held together by seams that stick due to the heat. TPO comes in rolls but is priced like any other roofing material. It is best suited for flat surfaces, which it was designed for. Homes with pitched roofs will want to avoid TPO. It's not designed to be attractive and must be installed in dry conditions, which is why it’s generally seen among commercial buildings. The quality of material in TPO can vary greatly between manufacturers, which leads to wide variations in pricing.

TPO has many good qualities as well. It’s a reflective material, which means you’ll save money on cooling and energy usage. It’s very simple to install, lightweight, and requires little maintenance. Since it’s made from recycled materials, this roofing also lowers your eco-footprint. This doesn’t quite paint the whole picture, as the materials needed to install TPO can add up fast. You’ll need insulation between your home and the TPO, which helps regulate heat. Depending on the thickness, this cost can be as much as the TPO itself. You’ll also need to add flashing to the seams and corners. Flashing prevents water leakage, and ranges wildly depending on your roof, such as whether you have peaks, dormers, or a chimney.

To attach TPO to your roof, you have three main options available to you. You can use glue to fasten the rubber to the underlayment, which is known as an attached roof. A fastened roof uses screws to hold itself down, and a ballasted roof uses rocks or pavers.

On average, your roof will cost roughly $8,600 to replace. The price varies based on the size of the home and what materials you want to use. When you receive a quote for a roof, you may be quoted based on square foot, or by square. They are different, with a square making up 100 square feet. Either way, the cost for labor is, on average, between $1.50 to $3.00 per square foot, or $150 to $300 per square.

Another factor that can raise the cost of a roof replacement is whether there is damage. If the roof is rotting, it’s not safe for a roofer to stand on it. Roofing companies will need to bring in equipment and fix the rotting, which will increase your costs. If you’re requiring the roof to be replaced under extreme weather conditions, this may alter your cost. If you have multiple layers of shingles, it may take more time (and therefore money) to remove them.

Material can account for 40% of the roofing cost. Asphalt can be as high as $5.50 per square foot. Metal, on the high side, can be $14, and clay or slate can go as high as $20 per square foot. Wood can go as high as $7 per square foot, but requires a lot of maintenance. Most people tend to go with asphalt, as it tends to last up to 30 years, and has a variety of colors to choose from.

If you’re going to replace the roof, and it's not an emergency, fall is the best season for the job. Autumn is a relatively dry season, and the weather is cooler.

There are benefits and disadvantages to any type of roofing. Asphalt is a common roofing material that comes in shingles. They’re an inexpensive option and straightforward to install. Metal comes in long sheets. It can be expensive to make and to install, but its seamless design is among the best available for roofing options. Metal is currently gaining in popularity, but that trend may not last. Rather, consider how it holds up in comparison.

Metal roofing is durable, and can withstand heat, water, wind, and hail. Once installed, it’s also quite easy to maintain. Because of its reflective nature, you can save energy costs in the summer, as metal will repel heat. Metal costs more to create and install, plus it’s heavier. If your home needs stability improvements to handle it, that won’t be cheap.

Asphalt is cheap to make, cheap to buy, and cheap to install. It’s relatively durable, though its longevity is only 50 years compared to metal’s 70 years or more. Asphalt has low snow retention, and extreme weather can harm it. It offers nothing in terms of energy savings.

If shingles need replacing, it’s a relatively straightforward job. You slide a new shingle in place and nail it down. Of course, anything on the roof is a safety hazard, so don’t take the job lightly. Metal roofs don’t need a lot of maintenance, but when they do, it’s a pain. If you use improper materials, it can cause the metal to corrode and create a bigger problem.

Both materials make for solid roofs. Asphalt has a few drawbacks, but is also the best for a tight budget. Metal costs more, but you gain durability, savings, and longer replacement costs. If you have the budget, you can decide if it's worth it.

Metal roofing is sold in squares, which are comprised of 100 square feet, and may also be called metal sheets. There are a variety of different metals you can choose from.

  • Steel roofs can come in two different types. The difference between the two types is what metal the steel is coated with. Galvanized is zinc, whereas galvalume is aluminum. Galvalume is cheaper and can go as high as $200 per sheet, whereas galvanized can go as high as $350.
  • Stainless steel is more durable and has a beautiful sheen to it. It’s considered a premium metal and is not a cheap option. It can run anywhere between $400 to $1,200 per sheet.
  • Tin roofs are a bit of a misnomer, as the actual material that comprises these roofs is called terne. This is steel coated with tin and can cost between $300 to $1,500 per square.
  • Aluminum is a cheaper option and can be recycled after you replace it. Compared to other options, it is a cheaper option at $600 per sheet on the high end.
  • Copper fades to a soft green over time and is highly durable. It can cost between $800 to $1,500 per sheet. It’s highly rust resistant and will have a long life.
  • Zinc is an attractive option that is available in both shingle style or standing steam to suit your aesthetic. Zinc usually runs between $600 to $1,000.

To install, metal roofing costs $3000 on average, though style, pitch, and coating can increase those costs. As always, size can play a factor as well. All the best roofing companies can break down your options for you and help you decide what the best option is for your specific circumstances.

Recent reviews for Alexandria Roofing Contractors

56101

We had five (5) windows replaced in September 2016 in our kitchen area as it was drafty in the winter time. The windows really sealed up the outside cold air and it is very comfortable and warm this past winter. I noticed a drop in our heating bills as ...

- Philip Albensi
56880

We upgraded all the windows and front door on our house in northern VA. The installers were super professional and went above and beyond to make sure we were satisfied. Great quality products and great service. Thanks Window Source of Virginia!

- Jared Smith
55789

Window Source of Virginia was extremely knowledgeable about Windows & Doors. We were looking to replace all windows and considering new entry doors; our goals were energy efficiency and safety. We were provided with multiple options at multiple price poi...

- Erica Selekman
56697

We had 22 Windows and 2 doors replaced. The product was high quality and the installation exceptional. We highly recommend Window Source of Virginia.

- John B.
516758

They took the time to understand my preferences, offering valuable suggestions and advice along the way. Their friendly and approachable nature made the entire experience enjoyable and stress-free.

- Bridgett Oliphant
548025

Roofers got the job done quickly and expertly. Very clean. Carpentry was fantastic.

- Bridgett Oliphant
103771

Thompson Creek did a wonderful job replacing my windows. I couldn't be happier but I just wish I called sooner.

- James M
49410

I made a request for a quote for a new front door. In the request I asked that I not be called and instead emailed. Of the 3 companies that porch matched me with, only Thompson Creek ignored my request. The agent was also unwilling to give a range of pric...

- Jordan Felle
105896

I couldn't be more impressed with my new bay window. Thank you for the wonderful experience!

- Katie S
548024

Roofers got the job done quickly and expertly. Very clean. Carpentry was fantastic.

- Bridgett Oliphant
152427

Responsive, knowledgeable, extremely professional and courteous service.

- Adrian Myers
60311

Before & After is an excellent company that strives to fully satisfy. This was the only company that truly listened to my desires and made sure to explain all possible options and limitations that could lie ahead. They have a trustworthy, courteous and h...

- RoseAnne Sciarrone

Everything You Need to Know About Alexandria Roofers

Who are the best Roofing Contractors in Alexandria?

We've found 50 roofing contractor providers that are available to you in Alexandria.

Keep in mind that every project has different requirements, and some roofing contractor professionals maybe be more equipped to handle the specifications of your roofing services work than others. Talk to multiple roofing contractors before deciding which one is right for you. You will want to consider how much they charge, if they are properly licensed for roofing services work in Alexandria, and if your project is a fit. Here are some suggested professionals and companies to get you started:

  • Complete Roofing Solutions
    • Location: Alexandria
  • U-CLEANNET USA
    • Location: Alexandria
    • Been in business since: 1998
  • DBS Roofing
    • Location: Alexandria
    • Been in business since: 2004

What Alexandria zip codes are served by Roofing Contractors?

Alexandria has 50 total Roofing Contractor companies that service multiple zip codes. We've put together a list of areas in and around Alexandria with the most Roofing Contractors:

  • 2 Roofing Contractors in 22314.
  • 1 Roofing Contractors in 22202.
      • 1 Roofing Contractors in 22310.

      Who should I hire if I need Roofing Services in Alexandria?

      Right now there are about 50 companies in and around Alexandria ready to help you with your roofing services project.

        Below we've listed a few of the top Roofing Contractors on Porch:

        All Roofers in Alexandria, VA

        Porch Pro Headshot Weathertight Exteriors LLC
        Roofers
        12121 Ridge Rd, King George, VA
        (2)
        Contact us in King George, Virginia, for a roofing company dedicated to your needs. We perform 24 hour service both residential and commercial. We will be there for you from emergency storm repairs to new roof installations. Call today to see what we can do for you. Certified with http://www.certa...Read more about Weathertight Exteriors LLC
        12121 Ridge Rd, King George, VA
        Contact us in King George, Virginia, for a roofing company dedicated to your needs. We perform 24 hour service both residential and commercial. We will be there for you from emergency storm repairs to new roof installations. Call today to see what we can do for you. Certified with http://www.certa...Read more about Weathertight Exteriors LLC
        Porch Pro Headshot Winfield Builders
        Roofers
        18213 Darnell Dr, Olney, MD
        (39)
        Replace your old windows in a flash when you opt for Winfield Builders in the Melwood area, a 4-star-rated company.
        18213 Darnell Dr, Olney, MD
        Replace your old windows in a flash when you opt for Winfield Builders in the Melwood area, a 4-star-rated company.
        Porch Pro Headshot Cole Roof Systems Inc.
        Roofers
        605 Princess St, Alexandria, VA
        When you need help with a vinyl siding project, reach out to the experts at Cole Roof Systems Inc. in Beltsville, MD.
        605 Princess St, Alexandria, VA
        When you need help with a vinyl siding project, reach out to the experts at Cole Roof Systems Inc. in Beltsville, MD.
        Porch Pro Headshot Boblits Enterprises LLC
        Roofers
        8372 Old Leonardtown Rd, Hughesville, MD
        (8)
        Proudly Serving Maryland, Virginia, and Washington DC Boblits Enterprises provides quality craftsmanship and professional Roofing and Construction services to its customers. We licensed bonded, and insured, and have been in business for over 25 years. We are committed to excellence and customer sat...Read more about Boblits Enterprises LLC
        8372 Old Leonardtown Rd, Hughesville, MD
        Proudly Serving Maryland, Virginia, and Washington DC Boblits Enterprises provides quality craftsmanship and professional Roofing and Construction services to its customers. We licensed bonded, and insured, and have been in business for over 25 years. We are committed to excellence and customer sat...Read more about Boblits Enterprises LLC
        Porch Pro Headshot Before & After Home Improvement
        Roofers
        4104 Chestnut Pl, Alexandria, VA
        (4)
        "I referred Damon and his crew to a client who needed repairs prior to selling their home. The works was done on time, on budget and the guys were a pleasure to have in the home at a stressful time. I highly recommend them."
        4104 Chestnut Pl, Alexandria, VA
        "I referred Damon and his crew to a client who needed repairs prior to selling their home. The works was done on time, on budget and the guys were a pleasure to have in the home at a stressful time. I highly recommend them."
        Porch Pro Headshot The Whiting Company
        Roofers
        Serves Alexandria, Virginia
        Located in Gambrills, about 5 miles south of the airport, Tim Whiting is a Roofing, Siding and Window specialist. they handle almost any product made in these areas. all work carries a manfacturers warranty which is usually a lifetime and his labor under full warranty up to 10 years . this busi...Read more about The Whiting Company
        Serves Alexandria, Virginia
        Located in Gambrills, about 5 miles south of the airport, Tim Whiting is a Roofing, Siding and Window specialist. they handle almost any product made in these areas. all work carries a manfacturers warranty which is usually a lifetime and his labor under full warranty up to 10 years . this busi...Read more about The Whiting Company
        Porch Pro Headshot American Cowboy Roofing, Inc
        Roofers
        Serves Alexandria, Virginia
        (9)
        Welcome to American Cowboy Roofing. We are your complete resource for exceptional and superior roofing, gutters, and siding renovations for your property. With over 40 years Experience, a Virginia Class A License, Fully Insured, a Certified CertainTeed ShingleMaster, awarded the 2021 Prince William ...Read more about American Cowboy Roofing, Inc
        Serves Alexandria, Virginia
        Welcome to American Cowboy Roofing. We are your complete resource for exceptional and superior roofing, gutters, and siding renovations for your property. With over 40 years Experience, a Virginia Class A License, Fully Insured, a Certified CertainTeed ShingleMaster, awarded the 2021 Prince William ...Read more about American Cowboy Roofing, Inc
        Porch Pro Headshot Castle Rock Construction  Inc.
        Roofers
        10910 Lombardy Rd, Silver Spring, MD
        (22)
        Faced with a vinyl siding challenge? Give the experts at Castle Rock in Chevy Chase Village, MD a call.
        10910 Lombardy Rd, Silver Spring, MD
        Faced with a vinyl siding challenge? Give the experts at Castle Rock in Chevy Chase Village, MD a call.
        Porch Pro Headshot U-CLEANNET USA
        Roofers
        5860 Mount Vernon Dr, Alexandria, VA
        (1)
        "I needed my bathroom and kitchen done, and it was such an outstanding job. It was professionally done and everything was on track and they had no problem with doing what I wanted done and how I wanted it. This is an outstanding team, I'd recommend them."
        5860 Mount Vernon Dr, Alexandria, VA
        "I needed my bathroom and kitchen done, and it was such an outstanding job. It was professionally done and everything was on track and they had no problem with doing what I wanted done and how I wanted it. This is an outstanding team, I'd recommend them."
        Porch Pro Headshot Exterior Remodeling  Inc.
        Roofers
        412 Hannes St, Silver Spring, MD
        Looking to do some home improvements? Task the professionals at Exterior Remodeling Inc. in Suitland, MD with your next vinyl siding project.
        412 Hannes St, Silver Spring, MD
        Looking to do some home improvements? Task the professionals at Exterior Remodeling Inc. in Suitland, MD with your next vinyl siding project.
        Porch Pro Headshot The Best Landscaping & Remodeling LLC
        Roofers
        Lakehurst, District Heights, MD
        (6)
        "<div><div style="background-color: black; opacity: .7; position: absolute; margin-left: 2; width: 170; height: 210; border-radius: 25px"></div><img style="position: fixed; top: 100; left: 77" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACQAAAAkCAQAAABLCVATAAAA9ElEQVR4Ae3QIU...Read more about The Best Landscaping & Remodeling LLC
        Lakehurst, District Heights, MD
        "<div><div style="background-color: black; opacity: .7; position: absolute; margin-left: 2; width: 170; height: 210; border-radius: 25px"></div><img style="position: fixed; top: 100; left: 77" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACQAAAAkCAQAAABLCVATAAAA9ElEQVR4Ae3QIU...Read more about The Best Landscaping & Remodeling LLC
        Porch Pro Headshot ac
        Roofers
        4800 Mark Center Dr, Alexandria, VA
        4800 Mark Center Dr, Alexandria, VA
        Porch Pro Headshot Lyons Contracting
        Roofers
        308 Calvert Ave # 103, Alexandria, VA
        We install all types of roofing, shingle roofs, cedar roofs, metal roofs and flat roofs. We work hard everyday to exceed our customers' expectations. Our crews are fully up to date on the latest training to insure the roof we install for you not only looks great but will last for many years. Roofs t...Read more about Lyons Contracting
        308 Calvert Ave # 103, Alexandria, VA
        We install all types of roofing, shingle roofs, cedar roofs, metal roofs and flat roofs. We work hard everyday to exceed our customers' expectations. Our crews are fully up to date on the latest training to insure the roof we install for you not only looks great but will last for many years. Roofs t...Read more about Lyons Contracting
        Porch Pro Headshot C.T. Remodeling INC
        Roofers
        Serves Alexandria, Virginia
        C.T. Remodeling INC Alexandria, VA, 22304 (703) 794-5578 C.T. Remodeling INC is a Remodeler from Alexandria, VA, specialized in Residential and Commercial Remodeling, Building Repairs, Bathroom Remodeling, Kitchen Remodeling, Electrical, Plumbing, Window Replacement, Roofing, Painting, New Construct...Read more about C.T. Remodeling INC
        Serves Alexandria, Virginia
        C.T. Remodeling INC Alexandria, VA, 22304 (703) 794-5578 C.T. Remodeling INC is a Remodeler from Alexandria, VA, specialized in Residential and Commercial Remodeling, Building Repairs, Bathroom Remodeling, Kitchen Remodeling, Electrical, Plumbing, Window Replacement, Roofing, Painting, New Construct...Read more about C.T. Remodeling INC