Chemical Roof Cleaning: What chemicals are used to clean roofs?

Chemical Roof Cleaning

Chemical Roof Cleaning

Chemical roof cleaning has become an essential method for maintaining the aesthetic appeal and structural integrity of roofs. By effectively removing algae, moss, lichen, and other organic matter, chemical cleaning roof techniques help prolong the lifespan of roofing materials. This article covers the most commonly used chemicals in roof cleaning, along with their benefits and safety considerations.

1. Sodium Hypochlorite (Bleach)

Sodium hypochlorite, commonly known as bleach, is a powerful disinfectant and cleaning agent widely used in roof cleaning solutions.

Benefits:

  • Effectiveness: Sodium hypochlorite is highly effective at killing algae, moss, and lichen.
  • Fast-Acting: It quickly breaks down organic matter, leading to immediate results.
  • Availability: Readily available and relatively inexpensive.

Safety Considerations:

  • Protective Gear: When using bleach, it’s essential to wear protective gear, including gloves and goggles, to prevent skin and eye irritation.
  • Dilution: Bleach must be properly diluted to avoid damaging the roof shingles and surrounding vegetation.

2. Sodium Hydroxide

Sodium hydroxide, or caustic soda, is a strong alkaline compound used in many industrial cleaning agents, including those for roofs.

Benefits:

  • Deep Cleaning: Excellent for removing stubborn stains and deeply embedded dirt.
  • Degreasing: Effective at breaking down oils and organic materials.

Safety Considerations:

  • Corrosive Nature: Sodium hydroxide is highly corrosive and can damage roofing materials if not used correctly.
  • Handling Precautions: Requires careful handling and appropriate safety measures to prevent chemical burns.

 

3. TSP (Trisodium Phosphate)

Trisodium phosphate is a water-soluble compound often used in heavy-duty cleaning products.

Benefits:

  • Versatile Cleaner: Effective against mildew, mold, and general grime.
  • Surface Preparation: Often used to prepare surfaces for painting by thoroughly cleaning them.

Safety Considerations:

  • Environmental Impact: TSP can be harmful to the environment, particularly aquatic life, if not disposed of properly.
  • Protective Measures: Gloves and eye protection are recommended during use.

 

4. Potassium Hydroxide

Potassium hydroxide, another strong alkaline cleaner, is used for its effectiveness in breaking down organic materials.

Benefits:

  • Strong Cleaner: Highly effective at removing tough stains and organic growth.
  • Multi-Purpose: Can be used for various cleaning tasks beyond roofs.

Safety Considerations:

  • Corrosive Properties: Like sodium hydroxide, it is corrosive and requires careful handling.
  • Usage Precautions: Proper dilution and safety gear are necessary to prevent injury.

 

5. Hydrogen Peroxide

Hydrogen peroxide is a mild antiseptic commonly used in cleaning applications due to its oxidizing properties.

Benefits:

  • Eco-Friendly: Breaks down into water and oxygen, making it environmentally friendly.
  • Safe for Most Materials: Generally safe for use on a variety of roofing materials without causing damage.

Safety Considerations:

  • Concentration: Higher concentrations can be hazardous and require dilution.
  • Storage: Needs to be stored in a cool, dark place to prevent decomposition.

 

6. Copper Sulfate

Copper sulfate is a chemical compound known for its antifungal and antimicrobial properties.

Benefits:

  • Effective Algaecide: Particularly effective against algae and moss.
  • Long-Lasting Results: Provides a longer-lasting solution compared to other chemicals.

Safety Considerations:

  • Metal Corrosion: Can corrode metals if not used carefully.
  • Environmental Impact: Toxic to aquatic life, so it must be used and disposed of responsibly.

 

7. Ammonium Sulfate

Ammonium sulfate is an inorganic salt with various agricultural and cleaning applications.

Benefits:

  • Fungicide: Effective against fungi, moss, and lichen.
  • Versatility: Can be combined with other cleaning agents for enhanced results.

Safety Considerations:

  • Skin Irritation: Can cause skin and eye irritation upon contact.
  • Application: Should be applied with proper protective gear to minimize health risks.

 

Wrapping Up

Chemical roof cleaning techniques are invaluable for maintaining roof health and appearance. By understanding the benefits and safety considerations of each chemical, homeowners and professionals can choose the most appropriate solution for their specific needs. Always prioritize safety by using the correct dilution ratios and protective gear, and consider the environmental impact of the chemicals used. For more detailed guidance and professional chemical roof cleaning services, refer to experts in the field .

Roof Inspections: What you need to know

Roof Inspection in Vancouver WA

Roof Inspections: What you need to knowRoof Inspection in Vancouver WA

Did you know that over 30% of homeowner’s insurance claims have to do with roofs? Imagine if your roof is leaking water, this can cause problems such as damaged walls, furniture, electrical systems which could end up causing power outages or fires. A healthy roof protects you and your family from the elements outside and being in the Northwest we get our fair share of rain, snow, ice.

We all know that when we are purchasing a home, the roof inspection is key; having a secure roof is one of the most important parts of a home, it can also be a very expensive investment, especially if you bought a home under the pretext that everything was okay. But that’s not the only time that roof inspections should be considered.

A standard rule of thumb for roof inspections is twice a year in the spring and fall this is to prepare your roof for the following extreme season. Although that can sometimes be a challenge to get the inspection done as often as it is recommended, you will help to prevent damage to your roof and also get on top of any issues that may be developing.

It is also important to do some DIY work on your roof. We recommend taking a picture of it and put a date on the photo so you can see changes more easily when comparing photos together. These noticeable changes can be given to your roof inspector to address during your inspection.

A roof inspection will determine the reliability of your roof and how long it could last. Roof inspectors have very specific procedures that they follow to identify the life of your roof without having to remove shingles or tiles. For example, a qualified roof inspector has equipment and techniques that enable them to see if your roof has “hot spots”; areas on the roof where heat is escaping. Infrared tools are used for this purpose and can show hot and cold temperatures on a roof without disturbing the roof.

Schedule your roof inspections now, and prepare your roof for the upcoming season, it could end up saving you money and saving your roof.

Custom Roof Cleaning

Custom roof cleaning in Vancouver WA

Custom Roof Cleaning

Custom roof cleaning in Vancouver WA

Your roof and its environment are unique. Cleaning your roof requires a custom approach each time. 

Portland, Oregon offers lots of ways to damage your roof. The rainy climate creates a damp growth environment for moss, mold, lichen, and algae. Our beautiful trees create shade for the moss and algae to continue to thrive. These trees shed leaves, needles, and debris that is carried by the wind and land in your gutters and on your roof. In the summer, add in UV sun damage and your roof is in need of care.

Moss, debris, and Portland elements all shorten the life expectancy of your roof. 

While you can’t control what happens on your roof, you can schedule an annual roof cleaning to prevent further damage. The reason? All the living plant materials on your roof build up over months. If the growing conditions are prime, and they are in the Pacific Northwest, then that moss thickens and spreads quickly. Rainwater, plus the moisture from the moss, absorb and hold the water on your roof, resulting in leaks and water damage inside your home. This is true for all roofing material: cedar shake, composition, and tile roofing.

Are you seeing black stains on your roof?

In addition to the green plants on a roof, you may notice black stains and streaks running down your shingles. Angie’s List identifies those as, “gloeocapsa magma, or GM, more commonly called mold or fungus.” This form of plant life is only found on the north and east sides of a roof due to less sun exposure. “GM has the ability to form an outer coating, protecting it from UV rays. When there is no light or low light, GM has a blue-green color. GM’s other self-protective factor is that it enjoys the cooler, shady areas of the roof where moisture is usually present.” Fascinating, right?

These black streaks aren’t just stains. They may also deteriorate asphalt shingles, by eating away at them as a food source, leading to water damage and roof rot.

Eco-friendly roof care is essential in the Portland and Vancouver metro areas.

Everyone has a story as to why they moved to the Portland-area or why they never left. One of the common reasons is that we simply love the beauty that the Pacific Northwest provides. That’s why we use eco-friendly cleaning methods on roofs. Hand-brushing, instead of using machines, not only benefits the life of your roof, but it is also an environmentally friendly method of roof cleaning to remove all that plant life on your roof.

When you work with us, we will clean and maintain your roof like the unique space that it truly is. Give us a call or send us an email and tell us what your roof needs. And if you’re up for it, share your Portland story with us as well.

Is Your Roof Ready for Fireworks Season?

Portland Fireworks

Is Your Roof Ready for Fireworks Season?

Sometimes the best view of the Portland and Vancouver fireworks is from your own roof. Watch safely and prevent accidental roof fires with these tips.

Clean your roof to prevent an accidental fire
Now is the time to schedule your professional roof and gutter cleaning to remove moss, dry leaves, pine cones, and small branches. This kind of debris on your roof, even if it’s just a small amount, can catch stray sparks from neighborhood fireworks. Most roofing materials are treated to be fire resistant, but there are still over 15,000 structure fires in the United States that are attributed to fireworks.

During a professional roof cleaning, your roof will also be inspected for missing and cracked shingles or any other hazards that can lead to fire vulnerability. Not only will this protect your home, but it will also make for a more comfortable and clean seat if you decide to watch the fireworks from your roof.

Trim your trees
Even if you aren’t ascending a ladder on the 4th to watch the fireworks display, any overhanging tree branches can catch firework sparks that can quickly jump to your roof. These branches can also brush against your roof, causing damage to shingles with every gust of wind.

Trimming branches near your roof line is a task that requires the proper safety equipment and skills. Also, consider that a falling tree branch can cause property damage as well. Hiring a professional is your safest bet when it comes to tree trimming, but if you want to go the DIY route, be sure to read up on how to do the job.

Keep fireworks away from your home
This seems like a no-brainer, but there are so many accidents attributed to fireworks that it bears repeating. Don’t point fireworks toward your home and be sure there is a safe distance between the fireworks and any structures and trees. Remember, most fireworks are often still burning as they fall from the sky. If you are putting together a fireworks display, read up on safety measures.

Watch the weather
If it’s hot and dry in the Portland-metro area at the beginning of July, avoid personal firework displays. Even if you won’t be lighting fireworks, your neighbors might. Start watering your landscape a few days prior to the 4th so your property isn’t a tinderbox waiting for a stray spark.

Fireworks and the 4th of July go hand-in-hand. With these tips, you and your family will be safe. Now, enjoy our beautiful waterfront fireworks display, and maybe a homegrown show as well.

Clean the Slate – Tile Roof Maintenance

Tile Roofing in Vancouver WA

Tile Roofing in Vancouver WA

Clean the Slate – Tile Roof Maintenance in Portland

A brief history of tile roofs

Tile roofs became popular in 16th century America as part of fire code safety in densely populated cities. By the 1900s we saw a decline in tile roofing, as lighter materials that were faster to produce took over.

Tile roofs today

Modern roof tiles are sometimes made of Portland cement (plus sand and water), while other tiles can also be made from sand (these do require an asphalt roof underneath).

Out here in the Pacific Northwest, we see plenty of homes with the distinct terra-cotta orange clay tile roofs. They always catch the eye and stand out in any neighborhood, whether the sky is overcast or blue. Other tile roofs in the Portland and Vancouver metro areas are the cement variety and come in an array of colors and styles.

Besides curb appeal and fire safety, clay and concrete tile roofs are made to last.

In the Portland, Oregon area, roof tiles can last over 50 years as long as moss, mildew, and lichen prevention is in place.

When tile roofs become brittle due to age and weather, they can break easily. Roof tiles also break when fallen tree branches hit the roof and with sharp temperature changes, especially if the tile was already cracked. Replacing broken tiles is necessary since water can seep through the cracks, causing damage.

Replacement tiles can be costly and if the roof is very old, tiles may no longer be mass produced. This requires a special tile order that is expensive and takes time.

What about tile roof maintenance in Portland?

Safety, first.
Anyone walking on a tile roof needs to be a professional — trained and skilled in how to maneuver on fragile tiles. That includes people who will be up there to clean windows, trim trees, and especially roof cleaners.

Gutters and downspouts.
Gutters and downspouts that are filled with moss and debris can cause water overflow to move under the tiles, resulting in mold, rot, and deterioration. A tile roof requires a reinforced roof deck, and replacing or repairing this because of water damage is costly.

Roof valleys.
And remember tile roof valleys. This is where roof planes meet to form a valley that allows rain to wash down the roof. When the roof valleys are filled with debris and moss, water dams build up causing water to spread under the tiles resulting in water damage.

HOA regulations.
If your tile roof is in an HOA development then you are required to maintain your roof on an annual basis. When it comes to tile roofs, DIY is not recommended. Hiring a professional who is trained and experienced with the intricacies of tile roofing is a must.

Homeowners insurance.
Your homeowner’s insurance will not renew your policy if there is too much moss on your roof. If your tile roof has damage due to moss, homeowners insurance will not cover these damages. Moss is considered an avoidable event due to improper maintenance or negligence, something that is prevented with annual maintenance, and therefore insurance companies leave it up to you to pay for the damage.

How we handle tile roof cleaning

  • We ensure all workers, plus their equipment, are under the weight limit for a tile roof edge. This prevents breakage when we are cleaning tile roof tiles.
  • Mildew, lichen, and moss can live on tile roofing materials. To remove these unwanted visitors, we use low psi (around 2,000) with a turbo nozzle tip.
  • Gutter cleaning is usually needed to prevent water damage underneath the tiles, and we always include this service in our estimate.
  • Ground cleanup is often the most overlooked, yet vital, aspect of tile roof cleaning. That’s because of the amount of debris and dirt that washes down the house to the ground. We ensure your home’s walls and the landscape looks just like it did when we arrived.
  • Most tile roofs in the Portland-metro area average 3-5 broken tiles. We can replace those tiles if you have them on hand.

A tile roof is a lifetime investment and can be a pretty spectacular aspect of any home in the Pacific Northwest. When it’s time to clean your tile roof the right way, trust professional roof cleaners to do the job with care and attention.

Roof Maintenance – How to Make Your Roof Last

Roof Care Building Blocks Vancouver WA

Roof Care Building Blocks Vancouver WARoof Maintenance – How to Make Your Roof Last

If you read our post on the top 3 reasons why you should clean your roof you’ll know that replacing your roof is expensive. Not only is it expensive but it can also be a headache and a long process depending on the weather. Proper roof maintenance is the key to keep leaky and damaged roofs out of the picture.

If you’re like most people, you probably want to avoid getting your roof replaced for as long as possible. Look below to find some ways to take care of your roof and keep that replacement out of sight and out of mind for years to come.

Inspect Your Roof Regularly

See a patch of green stuff or unusual black streaks on your roof? Maybe it’s time for an inspection. In fact, you should be inspecting your roof on a regular basis, which includes checking your ceiling from inside the house to make sure everything is intact.

These inspections don’t necessarily have to be extensive. Just enough to see that there’s no build up of debris on your roof or parts of it wearing and tearing. You especially want to keep an eye out for rust, leaks and buildup of moss when examining your roof.

Regular inspections is great because it keeps damages from getting worse and you always know what to expect. If you think a more thorough inspection is needed, have a professional come in to take a look and address any issues.

Keep Gutters Cleaned and Up to Date

Making sure your gutters are cleaned avoids severe damages to your roof. If you decide to clean gutters on your own, make sure you aren’t cleaning from your roof. It’s dangerous and less practical.

It’s best to use a firm ladder, a bucket for debris and scooping tools like small handheld shovels (make sure you’re wearing gloves too). You can also use a hose to rinse everything out once the bulk of cleaning has been done.

Although a simple task, there is a risk of injury when cleaning gutters so consult with a professional if you feel uncomfortable.

It’s also best to make repairs to your gutters before damages get worse. This’ll improve the longevity of your roof and keep high gutter replacement costs away.

Don’t Let Snow Build Up On Your Roof

Roof maintenance also includes inspecting and caring for your roof in harsh weather conditions!

If you live in a place that snows during the winter, like the Portland and Vancouver areas, it’s best to keep snow from building up on your roof. The weight, moisture and cold temperatures of the snow can damage both the inside and outside of your roof. It can also damage your gutters when weight gets too heavy to hold.

If you decide to clear snow off your roof, do so carefully. It’s very easy to slip and fall. Also, don’t use sharp objects like ice picks to clear the snow. Instead use a snow shovel and slowly scrape away. To melt the snow use calcium chloride.

The Bottom Line

Your roof can last much longer than you think if you put in the effort to take care of it or hire someone to do regular inspections and roof maintenance. Don’t let the elements chip away at your roof.

Proper Roof Care – 3 Things To Keep In Mind

Roof cleaning Vancouver WA

Roof cleaning Vancouver WAProper Roof Care – 3 Things To Keep In Mind

Roof care can be rewarding but also challenging and risky if the right approaches aren’t taken. You risk injury, damage, and other mistakes whenever you get on your rooftop to clean.

To help you avoid these things we have come up with a list of instructions for you to follow. Please use this list as a general guide and take any other precautions you feel are necessary.

1) Start by Choosing the Right Day

The good old weather forecast on your phone app or on the news can help with this. It’s best to check the weather before every getting on your roof, especially in place like Portland and Vancouver where weather can change quickly.

Ideally, you’d want to clean your roof on a sunny day with partially cloudy skies and little wind. You don’t want it to wet or too hot. Feeling comfortable while on your roof is one of the best ways to avoid injury. It’ll allow you to focus on your safety and doing a good job.

These conditions also allow your cleaning solutions to work without evaporating or washing away too quickly.

2) Move Surrounding Lawn Furniture and Items Out of the Way

Roof care can be both messy and toxic. It’s not uncommon for lawns to get littered with debris during a roof cleaning process. It’s also not uncommon for cleaning solutions to have chemicals in them that stain and corrode fabric.

It’s important to move any lawn furniture or items out of harms way to keep them looking nice. The last thing you want is to have a shiny roof but dirty furniture. Items also include cars in your driveway, garden gnomes, and swimming pools (of course you can’t move a swimming pool but covering it up would help).

3) Roof Care Safety

If you are at all skeptical about your ability to be on your roof make sure you have the proper safety equipment. This includes having a sturdy ladder, shoes with a good grip, soft kneepads and gloves.

A quick tip with your ladder: always make sure your ladder is on steady ground like a concrete sidewalk or wooden platform. Never lean your ladder against gutters.

The Bottom Line

You want to make sure the conditions are ideal for roof care. Make sure to do all the organization beforehand and buy all necessary equipment. No expense is too much to ensure the safety of your home, your family and yourself.

Why we don’t Recommend Pressure Washing Your Roof

symmetrical suburbs birds eye view

symmetrical suburbs birds eye viewWhy we don’t Recommend Pressure Washing Your Roof

Pressure washers are glorious tools that get the job done effectively and efficiently. But if pressure washing isn’t done right it can lead to some serious damages, especially for your roof.

While professionals use pressure washers for all sorts of things, you’ll most likely never see it used for cleaning roofs. Here’s why…

1) Damage to Shingles by Uplifting Them

Pressure washers are powerful machines and your roof’s shingles are really no match. While not noticeable right away, when shingles are pressure washed water gets into the cracks and strips away the adhesive material that keeps your roof together.

This is what keeps your roof together and protects your home from the elements. It’s just a matter of time until your roof starts taking a beating from the weather. Pressure washing your roof may make it look nice but it’ll shave years off its life.

2) Gouged and Damaged Wood

Pressure washing can also cause damage to your home exterior if not done carefully. When used to their full extent, pressure washers have been known to crack driveways so there’s no question that they can break wood.

Not only is this unsightly but water getting into wood is probably the worst home damage you can ask for. This can caused your wood to expand and bubble up. It can even cause wood rot from the inside out, which is very hard to take care of.

3) Spread of Moss and Fungus Across Your Roof

You also run the risk of spreading moss and fungus to other places on your roof, or even onto a neighbor’s roof. It doesn’t take much from pressure washing to send things in the air.

This is mostly because of the lack of control someone can have while pressure washing. Although it’ll look nice when the job is done, moss will come back quickly and in higher amounts.

The Bottom Line

Pressure washing your roof will do more harm than good. This is why professionals use soft washing and wire brush methods. They’re safe, controlled, and most importantly don’t damage to your roof. Forcewashing uses the wire brush method along with a gentle rinse and treatment.

Moss Removal Matters – Eliminate Moss Growth on Your Roof

Mossy Birdhouse Vancouver WA

Mossy Birdhouse Vancouver WAMoss Removal Matters – Eliminate Moss Growth on Your Roof

While sometimes it may look pretty, moss has the potential to cause severe damages on your roof. Mosses are small, green, flowerless plants that lack roots and seeds. Because moss lacks roots, they generally grow best in shady and wet areas. Moss removal is important for saving you time, money and stress.

Common signs of moss growth on your roof are black streaks and grass-like substances growing in the cracks of shingles. Since moss doesn’t have a root system, it grows by collecting and holding water in its leaves. This collection of water is what ultimately damages your roof and calls for moss removal services.

Now, if you aren’t afraid of being on your roof, there are a few things that you can do to prevent moss growth. Here are the 3 that Forcewashing recommends…

1) Remove Shady Areas on Your Roof

Moss loves the shade. It thrives in dark and cool areas. While there are some cases where you simply cannot help but to have shady areas on your roof, we would recommend doing your best to eliminate it.

Common cases where something can be done are trimming any nearby trees, taking down tenting near your home, and removing any unnecessary add-ons to your roof like overcompensating window shades or satellite dishes in darker areas.

A plus side to trimming trees that are near your home is that you’ll also avoid leafy debris falling on your roof – taking care of two things at once!

2) Use Store Bought Roof Cleaners to Impede & Eliminate Moss Growth

There are also several store bought solutions out there that can prevent moss growth! These work best for moss removal in areas of your home that are always shady and damp. Take a look at the list below…

Spray and forget outdoor cleanersSpray & Forget

This is a solution for removing, moss, mold and mildew off roofs and other surfaces as well. The name really says it all you simply spray and forget. No rinsing or pressure washing is required. It’s eco-friendly, biodegradable and is safe on all exterior surfaces.

 

Wash safeWash Safe Industries – Roof Wash

A professional roof cleaner specifically designed this product for cleaning roofs. To use, you simply mix it with water and spray it on your roof then you use a wire brush to gently scrape the moss away. This product does require some work to use it, but it’ll be worth seeing your roof shine.

3) Ensure Your Roof is Always Cleaned of Debris

Another leading cause of moss growth is debris on your roof. In order to further prevent moss growth you should keep it clean on a regular basis. This does mean going on your roof and inspecting regularly (maybe every 1-2 months) but it’s worth not having the headaches of a mossy or damaged roof later.

The Bottom Line

There are many ways to take care of moss growth on your roof. However, it can be unsafe and Forcewashing would not recommend going on your roof if you are uncomfortable or afraid to do so. It is best to contact a professional who specializes in moss removal and can get the job done safely.

Top 3 Reasons for Treating Your Home With Roof Cleaning

Well treated homes in Vancouver WA

Well treated homes in Vancouver WATop 3 Reasons for Treating Your Home With Roof Cleaning

A dirty roof is an eye sore and can mean unwanted damages with severe replacement costs. Upon costing a lot, roof damages and moss can be harmful to you and your family, making roof cleaning essential.

For those living in the Portland and Vancouver areas in the Pacific Northwest, mossy roofs filled with debris are no uncommon occurrences. But that doesn’t mean you should blend in with the crowd.

There’s no dispute on whether or not you should avoid costly roof repairs. Below you will find the top 3 reasons to keep your roof clean.

1) Freshen Up Your house and Make it Shine

Roof cleaning is hands down one of the best ways to boost your homes curb appeal. Think about houses that are for sale. Would you rather choose one with a mossy and debris filled roof or one that has been freshly cleaned and polished to perfection?

Also, those unappealing black stains, caused by moss growth, on your roof would be stripped away by a professional cleaner. Roof cleaners like Forcewashing uses a zinc sulfate solution after cleaning your roof, which keeps it safe from moss growth and black stains for at least a year.

2) Roof Cleaning is Much Cheaper Than Repairs

Of course, this is an obvious statement but it can’t be emphasized enough! Roof cleaning costs typically range from $200 to $550 while roof replacement can cost anywhere from $5,000 to $10,000.

Of course this depends on the size of your roof and house but it would take about 20 roof cleanings to meet the cost of one roof replacement. To put this into perspective, a 900 square foot roof can cost $5,500 while a roof cleaning can cost $260.

3) Protect Your Family From Getting Sick

You may not know this but moss and debris on your roof can cause unwanted mold and bacteria to enter your home. When your roof is left untreated for long periods of time, moss and algae start to form under your roof’s shingles and in cracks.

When this happens, the inside of your roof becomes damp and starts to mold. This bacteria spreads through your house and can cause sickness. Plus no one likes the bitter smell of mold.

The Bottom Line

There are many reasons to keep your roof clean but here is the top 3. It’ll make your home stand out, especially in places like Portland and Vancouver where mossy roofs are found frequently. It’ll also keep your wallet happy and your family safe!