A leaky roof is a common problem that affects many building owners. It can have a variety of causes, but is an issue that needs to be dealt with sooner or later due to the risk of structural damage. Protective steps like installing a roof coating can help in preventing leaks in some situations, but won't work for all causes. Read on for our comprehensive guide to different roof coating types, the main causes of leaks, how roof coatings can prevent some leaks, and when to know which approach to choose.
A roof coating is a fluid-applied roofing membrane that protects and extends the life of a roof. Roof coatings can be made from a variety of materials, and they each have their own advantages.
Silicone roof coatings are made from silicone polymers. They are an elastomeric roof coating and are reflective, making them UV resistant. They maintain their flexibility even during harsh weather conditions, and are unlikely to crack, peel, or bubble.
The silicone creates a watertight seal around the roof surface, plugging any holes or gaps. They are particularly effective on flat roofs where ponding water can be an issue because they do not degrade when wet.
Silicone roof coatings can, however, be more expensive upfront. It can also be difficult to re-coat with something else later on because the silicone creates such a smooth surface.
Because silicone doesn't shed, like an acrylic roof coating does, it generally has a longer lifespan. This lack of shedding, however, does mean that dirt can accumulate on the surface. This reduces its reflective capabilities over time.
Get in-depth information in our post "How long does silicone roof coating last".
Acrylic roof coatings are water-based and made from acrylic polymers. They have high flexibility and strong adhesion, and are lightweight.
Their main benefit is the high level of UV protection they provide. They are very reflective, and this reflectiveness does not decrease over time, like it does with silicone roof sheets.
They are not, however, as waterproof as silicone. Because of this, they may not be the best choice for flat roofs and those susceptible to ponding water. The water will degrade the acrylic material over time.
View our post for more information "How long does acrylic roof coating last".
Polyurethane roof coatings are made of polymers that are flexible and have a high impact resistance. Because of this, they can withstand both foot traffic and falling debris. They are also chemical resistant.
These traits make them ideal for commercial buildings and industrial settings.
Their flexibility means that they are unlikely to crack as the building expands and contracts, and their topcoat provides a high level of UV protection.
A roof coating works by creating a protective layer over the existing roof material. It has several benefits that can help to extend your roof's life and its appearance.
One of the major ways that they can protect your roof is through their waterproofing, which prevents some causes of roof leaks.
For more details check out our post "Can you make roof tiles waterproof".
Roof coating can prevent some types of roof leaks, but not all. Let's take a look at the situations where a roof coating could solve the problem.
Roof leaks caused by cracks or gaps in the roof can be stopped by a roof coating. This is because a roof coating fills up any gaps in the roofing, and all of the pores. This prevents water from entering.
Roofs can develop small gaps over time due to normal wear and tear, weathering, and UV damage. The seamless layer of a roof coating stops leaks due to these surface damages.
Acrylic roof coatings are most effective at preventing UV radiation damage that can lead to cracks and degraded roof surfaces.
Ponding water is common on flat roofs or roofs with a small slope. The pooled water can degrade the roofing material and lead to leaks.
Some roof coatings, particularly silicone roof coating, are highly resistant to ponding water. They create a waterproof barrier that prevents the water from reaching the roof structure.
On some roof types, the seams and joints may develop small gaps, especially when there are fluctuating temperatures. Applying a roof coating can fill in these gaps and prevent water from leaking through.
In this situation, a highly flexible roof coating would be most effective, such as polyurethane.
It is always important to get your roof assessed by a professional roofer before opting for a roof coating. Applying a coating may mask a more serious issue that needs addressing, and will get much worse if left untreated.
While a roof coating can solve a leaky roof problem in some situations, there are others where applying a coating would not solve the problem at all. These tend to be more serious damage that needs more extensive work to fix.
In some cases, a roof leak can indicate that there is a problem with the structural integrity of the roof deck. This is the layer beneath the outer roofing material. The issue could be rot, warping, or other types of significant structural damage.
A roof coating won't fix the underlying structural issues, and these will need to be addressed before any coating is applied. In the most severe cases, a roof replacement may be needed.
While smaller cracks can be filled in using a roof coating, it won't be effective against large cracks. These cracks or holes could be caused by fallen debris, storm damage, or significant long-standing wear, and they will need to be fixed before a roof coating is applied.
This work could include patching or section replacements in more severe instances.
Flashing is installed around the edges of fixtures such as chimneys, skylights, and vents. Its purpose is sealing the gap where the roof meets the wall, and directing water towards guttering instead of more vulnerable areas.
When it fails, water can enter in the gap between the roof and the wall. A coating won't stop roof leaks caused by damaged flashing because they don't adhere to metal flashing, and they won't fix any of the present damage.
The flashing will need to be repaired or replaced separately before a coating is considered.
Clogged gutters can cause water to back up and leak into the roof edge or fascia board. A roof coating won't fix drainage issues, and these will need to be addressed directly to ensure that water drains off the roof as it should.
A roof coating won't address a missing or cracked tile or shingle. When tiles are heavily damaged, cracked, or missing, they expose the roof deck to external moisture, and this can quickly start to degrade the roofing materials.
These tiles should be replaced to maintain the roof's integrity before applying a roof coating.
Ice dams are usually caused by a combination of snow build-up and heat escaping from the thermal envelope and into the roof space. This creates a situation where snow melts and refreezes, causing an ice dam at the roof's edge. Water will then pool there, which can seep underneath the shingles.
While a roof coating can create a waterproofed seal that prevents water from seeping through, it is not designed to deal with the insulation that has caused the heat leakage in the first place, and this will need to be addressed separately.
A roof coating helps to prevent leaks in some situations, and it can also provide other important benefits.
Reflective roof coatings bounce UV rays off the roof instead of allowing them to be absorbed. This can help to reduce the cost of cooling your home because it prevents the sun from warming the building.
By protecting it from the elements, a roof coating can extend the life of your roof. Roof coatings can last anywhere from 10 to 20 years, or more.
This makes them a worthwhile and cost-effective investment that can delay the need for a roof replacement.
Roof coatings are an environmentally friendly option for a few different reasons. First, they reduce the number of times that a roof needs to be replaced. The impact of this is fewer materials needed, and less energy spent on creating those materials and installing the roof.
Secondly, the creation of a cool roof through reflecting UV rays reduces energy use and the building's carbon footprint.
Of the three types of roof coating we've covered, polyurethane is the most environmentally friendly material. It can often be recycled and it contains fewer toxic materials. Silicone is less environmentally friendly. It is more difficult and expensive to recycle and it is not biodegradable. It does use sand, however, which is a less finite resource than used in other types of coatings.
Acrylic roof coatings are the least environmentally friendly of the three because it contains microplastics and it isn't recyclable.
Roof coatings are not the only option to stop roof leaks. Other options include:
If you are dealing with a roof leak and you are looking for a solution, we can help. Our experienced and professional team will thoroughly assess your roof to determine the root cause of the leak and whether it is a good candidate for a roof coating. If it is, we will go through the different roof coating options with you and provide expert advice about which could work best with your roof.
Our roof coatings always use high quality product, and are installed to a professional level that will stand the test of time.
A roof coating provides a waterproof seal to a roof that can prevent leaks in certain situations. For example, when there are small cracks or gaps, minor seam issues, or ponding water. They won't work if there are more serious structural issues causing the roof leaks, and only a professional roofer can determine what the best cause of action is.
