The Complete Guide to Rubber Roofing

An Introduction to Rubber Roofing

Owners of homes with flat and extremely low sloping roofs have traditionally had a problem with leaks. Because there is no way for rainwater to roll off, it builds up and eventually seeps through the ceiling.

Rubber roofing offers a solution, as it repels rainwater, allowing it to dry naturally.

Pros of Rubber Roofing

Rubber roofing has several advantages over traditional felt flat roofs. With felt roofs, the slightest tear can cause the roof to leak.

– Rubber roofing is durable, lasting anything up to 50 years without needing to be replaced, and does not tear anywhere near as quickly as felt.

– It can survive in temperatures ranging from -62 degrees to 300 degrees Fahrenheit without cracking or deteriorating.

– It is low maintenance—rubber roof repair is easy and can be done by merely applying a low-cost rubberized solution available at any hardware or building supplies store.

– Rubber roofing adds value to your home, too. It has a class A fire rating and is favoured by most home insurance companies.

– Finally, it is an excellent insulator. It can absorb heat in hot weather and release it in colder weather, thus reducing your heating and air conditioning bills.

– Another advantage of rubber roofing is cost-effectiveness. It is by far the least expensive type of single-ply flat roofing material and weighs less than a third as much as slate roofing tiles.

Cons of Rubber Roofing

Not everyone is enamoured of rubber roofing, however. Modified bitumen roofing systems being erroneously described as “rubber roofing” has sometimes caused realtors and building inspectors a headache. Also, there is a little margin of error for roofers.

– If installed incorrectly, it can leak even worse than felt roofing. Fortunately, most rubber roofing manufacturers offer certification schemes to ensure that their products are correctly fitted.

– Make sure a roofer installs your rubber roof with the appropriate certification unless you are doing it yourself, in which case you need to make sure that every seam is flush and that there are no gaps.

– Rubber roofing is also relatively new to the market, so there could be problems that have not been noticed yet. They first appeared around 30 years ago, which is generally regarded as the minimum lifespan for this type of roof, so the first ones are starting to wear out around now.

– The effects of this will become clear as time progresses. Until then, they remain a hard-wearing and inexpensive option for people with flat roofs.

Installation of Your Rubber Roof

This part of the article will provide a step by step guide to rubber roof installation for those who wish to perform this task themselves rather than employ the services of a professional roofer.

Tools & Materials

The list of items required for rubber roof installation is a fairly short one. Apart from the roofing material itself, all you will need is a :

  • knife or scissors
  • bonding adhesive
  • a paint roller to apply the adhesive
  • a broom to sweep away any debris
  • Also, it is advisable to wear gloves to protect your hands and some form of eye protection
  • If you are installing a rubber roof over the top of an existing roof, you will also need some kind of plywood baseboard to lay underneath the rubber.

To bond properly with the rubber membrane, the baseboard should be sanded, thoroughly cleaned and completely dry.

If you plan to attach the rubber to vertical surfaces such as walls, you may need some metal strips to affix the rubber properly. You can buy inexpensive aluminium termination bars, especially for this purpose.

Rubber Roof Installation Step By Step

If you are installing black rubber roofing, it is best to do so on a cool, dry day with a fair amount of cloud cover.

Not too cool, though, since latex bonding adhesive requires an ambient air temperature of at least 50 degrees Fahrenheit, or 10 degrees Celsius, for 48 hours after application.

One needs to get the temperature just right because on a bright, sunny day. The rubber roofing membrane can become hot very quickly due to the black rubber absorbing the heat from the sun’s rays.

Also, since the rubber is very heavy, it is advisable to have at least one other person to help you with it.

The good news is that rubber roofing material comes in rolls of anything up to 50 feet wide and 100 feet long, so the amount of cutting and shaping that you will need to do is relatively minimal, especially when compared to tile roofing. It should be possible to cover most roofs seamlessly.

You are now ready to begin the installation of your rubber roof.

  • Start by sweeping the roof thoroughly to remove any dirt or debris.
  • Once the roof is clean, you can begin applying the latex bonding adhesive with the paint roller. Make sure that the adhesive is applied evenly, to prevent air bubbles in the rubber, and be careful not to paint yourself into a corner.
  • Lay down the rubber roofing and then sweep it again with the broom to make sure that it lies flat against the surface and that there are no wrinkles.
  • Wait half an hour for the adhesive to bond, and then repeat the sweeping, from the centre outwards.
  • Use the scissors or utility knife to trim any unwanted rubber from above the termination bars, if applicable, and apply latex tape over any seams that may exist.
  • Your rubber roof installation should now be complete for a typical flat roof. A more complicated roof, for example, one that is an odd shape or has pipes and other fixtures that you need to work around, may require more specialist advice.
  • Home improvement stores should be able to advise you of any special equipment you may need, or whatever else you need to take into consideration when dealing with the hard cases in rubber roof installation.

How to Repair Your Rubber Roof?

One of the most significant advantages of rubber roofing is that it requires very little maintenance. But occasionally, your rubber roof will need repair. This part of the article presents a quick and easy guide to show you how to repair your rubber roof, should it ever become necessary to do so.

Sealants for Rubber Roof Repair

While severe repairs may require replacement of your rubber roof coating, minor rubber roof repairs can be carried out using a liquid rubber sealant cement that comes in a tube, or by applying the special rubberized tape.

Tubes of rubber roof repair sealant cement typically come in 10oz sizes and contain oils mixed with the liquid rubber that help it to penetrate and fill any cracks that may have appeared.

You can also buy tapes to help in rubber roof repair. Ordinary duct tape won’t do the trick here. The tape needs to be a specialized type made specifically for repairing rubber roofs.

It is made from a combination of resins and rubber. It is backed with a powerful adhesive that is able to withstand extreme heat and cold, and which is resistant to ultraviolet rays so that it does not deteriorate due to the ravages of the weather.

Liquid rubber cement for rubber roof repair comes in a variety of colours, to match the colour of your roof.

The Effect of Cleaning on Rubber Roof Surfaces

In 1992, the US Army released the results of a study assessing the results of 16 different cleaning methods on the rubber roofs of its installations when preparing them for patching.

The study concluded that the application of a droplet of dimethylformamide, commonly abbreviated to DMF, applied with an eyedropper, can adequately indicate the bonding condition of aged rubber roofing.

It recommended that all contaminants be removed so that the original colour of the roofing material is restored before any patch is applied.

When cleaning rubber roofs for repair, make sure that you change brushes or cloths often, to avoid re-depositing dirt on the surface.

The Army’s recommended method for cleaning was a wire brush applied to an electric drill, to apply vigorous abrasion to the surface.

The results of this study show the durability of rubber roofing. With cleaning, the condition of the roofing can be returned to almost the same as when it was new. Such cleaning allows it to be patched in such a way that it can last a lifetime, even if a crack or wear and tear should occur.

Coatings for Your Rubber Roof

When merely patching up your rubber roof with sealant or tape is not enough, it may become necessary to apply a new coating to your rubber roof. 

Rubber roof coatings come in two varieties, a liquid rubber that you apply like a coat of paint, and rubber sheeting that is bonded to your original rubber roof installation with a unique adhesive. In this part of this article, we will look at the advantages and disadvantages of each type of rubber roof coating.

Liquid Rubber Roof Coatings

Liquid coatings for your rubber roof come in a range of colours, most commonly black, white and grey, to match the original colour of the roof.

They are applied with a brush or roller, just like paint, and you can apply up to six coats, depending on how thick the replacement rubber needs to be.

This makes it a more versatile solution than sheeting. No primer or topcoat is needed; the liquid rubber is applied straight to the surface.

Manufacturers claim that liquid rubber roof coatings can extend the life of a rubber roof by up to 20 years if applied correctly.

When applying liquid rubber roof coatings, you must be sure to take care that the surface is even. If you have ever seen a rushed paint job, you will know how ugly uneven paint can be.

Now imagine that applied to the surface of a flat roof. If your supposedly flat roof resembles a topographic map of the Himalayas, it would not only look bad (which doesn’t really matter that much, since few people will see your roof). Still, it could also cause surface water to gather in the ridges after a rainstorm, a process known as ponding.

This makes it more difficult for the water to evaporate once the rain clouds part, and can shorten the lifespan of the coating.

However, you have to bear in mind that rubber roof coatings are incredibly durable, and so will not bubble and crack like other roofing materials, so this shortened lifespan is only relative.

But naturally, most people will want to prolong the life of their roof as much as they can anyway, and taking that little extra care provides a way to do this.

The Use of Sheeting for Coating Rubber Roofs

Rubber roof coatings also come in sheet form. Some manufacturers will provide them custom made for the shape of your roof, in sheets of up to 10,000 square feet. If you are looking for a less expensive solution, you can buy them off the shelf.

Sheets should be applied in a grid-like fashion, with the edges slightly overlapping. Make sure that the joins are airtight. Otherwise, water could seep in between them.

The advantage of this type of rubber roof coating is that it is easier to apply than a liquid coating, though it does require a primer and the use of special adhesive to make sure that it bonds to the original surface correctly.

One must be careful to lay it flush with the original surface; otherwise, air bubbles could appear underneath the rubber sheet.

The Joy of Rubber Membrane Roofing

In days of old, flat roofs were made of asphalt, with gravel used as ballast. This made it very difficult to locate the source of a leak, as the gravel would hide it better than the illustrations in a Where’s Waldo book.

Now, thanks to the invention of rubber membrane roofing, this problem has largely been eliminated.

The Rise of Rubber

In recent years, rubber has grown in popularity as a roofing material. While rubber roof shingles are available for those who want to maintain a traditional appearance for their roof, rubber membrane roofing is the most common option for those with flat or gently sloping roofs.

Coming in either roll or sheet form, it allows people to cover most roofs seamlessly. It can even be used on your RV.

The rubber membrane roofing material is known as EPDM, which stands for Ethylene Propylene Diene Monomer, and comes in a variety of different thicknesses.

45 mil EPDM, about the thickness of a dime, should be sufficient for most flat roofs, but in areas with an increased risk of punctures, such as a place with overhanging tree branches that could fall and pierce the roofing membrane, 60 mils (about the thickness of a quarter) and 90 mil EPDM is also available.

EPDM first came to prominence as a roofing material in the late 1970s, after a history of being used in hoses, tires and other moulded products since the early 1960s.

In the last decade or so, it has really taken off in popularity and now has a 22% market share among roofers, making it the most popular material for new roofs as of February 2018.

Rubber Membrane Roofing for Your RV

One area in which rubber membrane roofing is becoming increasingly popular is as a roofing material for recreational vehicles or RVs.

As with flat-roofed housing, it has gained in market share with RV owners over the last few years because of its lightweight and ease of installation. It has disadvantages over more traditional metal or fibreglass RV roofs, however, due to the risk of being torn by overhanging branches.

RV owners should maintain their rubber membrane roofing at least twice a year by cleaning it with warm soapy water and applying two coats of UV protectant spray.

It is possible to buy a complete kit containing everything you need to install rubber membrane roofing on your RV.

These kits contain the rubber membrane roof itself, the adhesive needed to affix it to the RV and butyl tape to seal around the edges. They are available from all good RV supplies stores.

Recent Posts