Flat Roofing Materials Compared

There are three basic types of flat roofing materials, although there are variations within the three categories that allow building owners to have more choices. Whether your building is new and this will be its first roof or you are replacing older roofing material, here are the three main categories you will be able to consider. There are inherent advantages and disadvantages of each type.

Built-Up:

Built-up bituminous roofs have been the standard for many years. They are still relatively popular primarily because they are inexpensive.

Built-up bituminous roofing is created using layers of hot tar, gravel, a smooth river stone ballast and tar paper or fiberglass membranes. Other than the lower cost, the advantages include fire resistance and some people think the appearance is more attractive.

There are several disadvantages. The material is very heavy. The underlying joints of the roof may need to be strengthened in order to install this type.

The installation itself is messy and smelly. It is not a do-it-yourself job for the building owner.
Once installed, it is hard to find leaks in the material and repairing leaks can be difficult. As time goes by, the gravel can break loose and clog the gutters. This choice is not recommended for buildings that are currently occupied.

Modified Bitumen:

Modified bitumen sheeting has a mineral-based surface to convey the fire resistant benefits of built-up bituminous with less weight. The sheeting consists of a single layer that is rolled onto the roof. The sheeting may be attached using a “torch-down” system, although newer modified bitumen rolls have a peel-off backing that sticks to the existing surface. The peel-and-stick installation can be a DIY project for the building owner.

One advantage of modified bitumen has to do with the light colored minerals that are embedded in the sheets. The minerals reflect heat, which can convey energy savings in areas where summer air conditioning costs are high. This is also an affordable alternative.

The main disadvantage of the torch-down system is the risk of fire. The process is not recommended for buildings that are currently occupied. The sheets are not the most resistant to scuffs and tears. Modified bitumen is considered less durable than the next type.

EPDM:

EPDM is a type of synthetic rubber. It resembles an inner tube but has been engineered to resist damage from sunlight. EPDM sheets are available and can be anchored with fasteners, glued on or ballasted with stones. Liquid Roof is another form of EPDM rubber is also available for waterproofing or coating existing roofs to extend the lifespan of the roof.

The advantages include easy installation and high durability. Rubber is inherently accompanied by a reduced risk of leaking. If leaks do occur, they are easy to locate and repair. There may also be a sound-reduction advantage.

The only disadvantage may be heat absorption depending on the color selected. Lighter colors are recommended for warm climates but may cost more.

Some building owners feel that the cost is a disadvantage. EPDM does cost more than other roofing materials. But because it is more durable and typically lasts longer, EPDM may cost less in the long run.

For product information or ordering visit EPDM Coatings or call them at 855-281-0940.

The Causes of Ice Dams and How to Prevent Them

Ice dams occur due to uneven temperatures on a sloped roof. The greater the slope of the roof, the more damage an ice dam can do. The process is usually set into action by snow, although an ice storm could also be the trigger.

What happens is that snow or ice on the higher portions of the roof melts. The melt or water flows down the slope until it reaches a point on the roof where the temperature is below freezing. Often, the point that is below freezing is an overhang where there is little or no warming from radiation, convection or conduction of heat.

When the water reaches the lower temperature, it freezes. Water from above continues to flow down the slope and remains liquid until it reaches the ice. Over time, the result is an ice dam. It is a dam in that it traps water behind it. The water can only freeze if it reaches the colder portion of the roof.

Icicles typically form below the dam as some melting occurs during the day. Seeing icicles along the edge of a roof can be a sign that an ice dam has formed.

The damage that occurs to the building is mainly from the water, although the weight of the ice can also cause damage if the overhang on which it rests is not strong enough to support the weight. The water behind the dam searches for an outlet. It starts to work its way through the roofing material and into the insulation.

Once inside the building, the water spreads through the insulation and down the interior walls. It can also spread across the ceiling causing stains and damage to dry wall or other materials.

Ice dams can be prevented in the planning stages of a newly constructed roof. Additional insulation can be used to make sure that the ceiling is airtight. Warm air travels through the ceiling and into the attic space. The warm air rises, causing the higher portions of the roof to be warmer than the lower portions.

Reducing heat loss prevents snow melt. The roof must be strong enough to support the extra weight of the snow. In areas where a large amount of snow falls on a regular basis, there are usually requirements concerning the load that a roof can bear.

Snow rakes can also be used to remove snow and prevent ice dams. Caution is required when using the snow rakes to avoid personal injury and prevent damage to the roofing materials.

There are products like elastomeric roof coatings, liquid rubber and liquid roof that are one the best products in the market to save your roof from damage.

For product information or ordering visit EPDM Coatings or call them at 855-281-0940.

Things to Remember When Applying Liquid EPDM

1)      Catalyst must be added prior to use.  Scrape sides of container with a rubber spatula to ensure catalyst distribution.

2)      Xylene or Mineral Spirits Solvents may be added to adjust viscosity or for clean-up.

3)      Easiest way to spread the rubber on a flat surface is to broadcast material with a rubber squeegee then roll using a short nap roller.  Product is self leveling.  A flat spatula can be used for small areas.

4)      Product has a long pot life after catalyst has been added; 4-6 hrs. depending on temperature.

5)      Only temperature affects the rate of cure.  Relative humidity has no influence. 

6)      Product is hydrophobic (sheds water) so substrate to be coated must be dry initially.  The uncured rubber can get wet or even have ponding water, with only a cosmetic effect after application, and will still cure.

7)      The rubber will penetrate into porous substrates such as wood and poured concrete.  A primer/sealer should precede application of rubber.

8)      The chemical reaction of the catalyzed rubber can be arrested by freezing the material.  This can keep material usable for weeks or months.  To use again simply allow it to reach room temperature and apply.

Liquid EPDM Coatings are aftermarket roof sealants

A number of aftermarket roof sealants are available, including urethanes, acrylics and liquid rubber. Liquid EPDM rubber is by far the most durable of the sealants available and has the widest range of applications.

It is more water resistant than other rubbers, including neoprene. It is more resistant to swelling and has a wider range of acceptable temperatures. It can be applied directly to practically any roofing material other than asphalt and can even be used on wood that has been primed.

Liquids have an obvious advantage over sheets. Sheets have seams. Seam sealers eventually deteriorate and water gets through the seams and under the sheeting.

Liquid EPDM can be used on top of neoprene, although some pre-treatment of the surface is required. Just knowing that the liquid rubber is recommended for use on top of the other type of rubber should be an indication that the material is more durable.

Liquid EPDM can also be used on top of polyurethane after a light sanding. It is somewhat surprising that urethanes are still used as aftermarket roof sealants. It is known that the structure is damaged by UV light and that discoloration occurs relatively quickly. Anyone who has made the mistake of using urethane as a roof sealant should consider applying liquid EPDM to truly protect the roof.

The liquids can also be used to seal existing leaks. They are self-adhering and fill up tiny fractures that let water through. It is a good idea to use a thick coat and cover the entire surface instead of attempting to only cover the leaky area.

When covering the entire roof, the liquid rubber reduces heat buildup. Not only does the roof stay cooler, but the interior of the building or the vehicle will also stay cooler. This benefit may reduce heating costs and keep the occupants more comfortable.

Liquid EPDM has become the most popular choice for RV roofs, because of all the above-mentioned advantages. It extends the lifespan of the roof and requires less maintenance. It lasts up to three times longer than any other aftermarket RV camper rubber roof sealant and also reduces noise from rain.

As far as price goes, most sealants are similar in price. Depending on where you buy, EPDM may be a little more expensive, but because primers and additional coats are not usually necessary, and because it lasts so much longer, owners who choose this aftermarket roof sealant save money in the long run.

How to Maintain Your RV EPDM Roof

With proper care and maintenance, your RV EPDM roof can last for 20 years or more. That’s pretty much equivalent to the life of the vehicle itself. One of the benefits of EPDM Rubber roofing materials is that the care and maintenance required is minimal. Regular cleaning is the first step.

Most manufacturers recommend cleaning the roof at least four times per year. The cleaner used should be one that is specifically designed for EPDM roofing and is free of petroleum distillates.

Products containing petroleum distillates, whether they are designed for cleaning or protecting, will cause the rubber to swell and loosen. There are many chemicals that fall under the category. The easiest way to tell for sure that the cleaner you are using does not contain any of the chemicals is to look for one that states on the label “free of petroleum distillates, safe for use on RV camper rubber roof.”

Cleaning is a relatively simple matter, but you should keep your safety in mind. If you are going to be getting up on the roof, you should be on your hands and knees to reduce your risk of falling.

The first step is to rinse the roof thoroughly with plain water at a relatively high pressure. Any branches or sharp objects should be removed by hand, if possible. While EPDM is tear resistant, sharp objects can cause scratches when they are pushed along the surface. Eventually the scratches can become tears.

Once all debris has been rinsed away, you will need to take a medium bristle brush, a bucket of safe cleanser diluted with water and get up on the roof. You need only scrub in areas where you see stains or dirt.

Keep your hose with you so that you can rinse while you are cleaning. Start in the corner farthest away from your exit point and work backwards to minimize the amount of time you spend on the wet surface.

After the roof is cleaned, you can use an EPDM protectant if you like. The protectant should be specifically designed for EPDM roofing, not for other types of materials. Some EPDM manufacturers also sell special protectants. While using the protectant is not essential, it may extend the life of the roof and reduce your need to restore or repair the roofing material.

Finally, proper care of your EPDM roof includes parking it in an area where the roof is protected as much as possible. Don’t park around fruit trees. The citric acid can deteriorate the material in between cleanings.