The roof is the most important part of your home’s exterior. After all, it keeps your heating in and the rain, snow, and wind out. Whether you’re purchasing a house or have owned one for a few years, it’s a good idea to check the condition of the roof and know how to go about renovating it.
Here you’ll learn everything you need to know about your roof, including the best time to book roofers for repairs or a full replacement. You’ll also learn about different types of roofs and which materials are best for each!
The lifespan of a roof may change over time. Inclement weather, nearby trees, and even local animals or insects could cause some damage to your roof, forcing you to repair or replace it earlier than anticipated. While you can’t prevent a winter storm from blowing in, you can make sure it undergoes routine maintenance to keep it in good shape. Semi-annual inspections are also a good call, whether performed by you or a trusted professional.
We know that picking a contractor can be daunting, so we’re here to help. After you’ve learned a bit about roofing, we’ll go over a list of questions to ask potential contractors so that you can get the best quote and roofer for your project.
When is the best time to change your roof?
Unlike interior renovation projects, roof replacements can only be done during certain times of the year. Roofers aren’t going to tear up asphalt shingles when they’re buried under an inch of ice, after all.
If your flat roof has an elastomeric coating, it’s best to schedule your project to be done between March and December. Roofs with shingles on the other hand can be replaced as soon as the snow melts in the spring up until late October. Be sure to hire your contractor as soon as possible – they’re in high demand when the weather gets warm!
Ideal temperature for a roof renovation project
Spring is when roofers are the busiest – the temperature is warmer and water leaks have begun to appear. Early and late summer aren’t too bad either, but keep in mind that roofers may have to postpone projects when temperatures are high. Since asphalt shingles absorb heat, they can become too hot to handle without gloves, making them difficult to install. Wind and rain can also cause project delays, especially for sloped roofs; it’s not safe to work on them during inclement weather.
In the winter, the snow and cold make it much more difficult to install shingles properly. They’re usually attached with nails, but sometimes that method isn’t possible. For example, if a flat roof needs urgent repairs during winter, the shingles may just be glued on. The cost will be quite steep. That said, roofers won’t install shingles on sloped roofs in colder temperatures because they’re prone to breaking.
When to contact a roofing contractor
Once you’re ready to renovate or replace your roof, you’ll need to reach out to a professional roofer. Timing is important here – you shouldn’t wait until you need emergency repairs done. And if you know your roof is reaching the end of its useful life, make an appointment ahead of time, even a year prior, so that it can be redone in spring.
To get a good price, try to reach out before high season arrives. Late February is ideal, but you should still be able to find a contractor up until late May. After that point, you may have difficulty finding someone with any availability.
Best roofing materials for sloped roofs
Most homes have a sloped or pitched roof! Its triangular shape not only makes it a more stable and solid structure but also allows snow, ice, and rain to slide off more easily. Sloped roofs need less maintenance and have a longer lifespan than flat roofs, too. When choosing a roofing material, you’ll need to consider your needs and budget, as well as each material’s pros and cons.
Asphalt shingles comprise three layers: bitumen, asphalt, and fibreglass. They’re cheaper, more heat resistant, and less likely to curl up than other options. They’re also relatively easy to install and require little maintenance. That said, they’re not able to handle temperature fluctuation and inclement weather as well as other roofing materials. Since they’re black and contain petroleum, asphalt shingles can cause the temperature of your roof and attic to increase significantly.
Aluminum shingles are made entirely from aluminum. They’re much more resistant to extreme weather conditions than other materials, and they require almost no maintenance. Aluminum is also much lighter than corrugated steel panels. With a lifespan of nearly 70 years, aluminum shingles are a great investment, albeit a little more expensive.
Keep in mind that aluminum shingles don’t provide good acoustic damping, so it may be a little noisy during rain or hail. They also have poor impact resistance and provide little heat insulation, meaning that you’ll need twice as much insulation if you opt for them.
Steel panels have the advantage of a long lifespan: they can last up to 50 years. They provide superior protection against ice and snow and are recyclable! Steel panels can also be installed in the winter. Although less vulnerable to rodents, vermin, and other infestations, this material is susceptible to salty air. So, if you live near an ocean or large body of salt water, go for a different material.
Slate shingles are available in many colours and are used for very old buildings. While they’re highly durable and resistant to inclement weather, they’re also expensive and quite heavy. Before slate shingles can be installed, an expert would have to assess whether the roof frame can bear the weight.
While clay tiles are a less common option, they are still available on the market. This eco-friendly roofing material is durable, expensive, and, like slate shingles, extremely heavy. You’d need a professional to determine if your roof’s frame could handle the weight.
Cedar shingles are aesthetic and durable. This lightweight roofing material can easily be replaced and provides good heat insulation. Cedar shingles are, however, expensive and require significant maintenance to prolong their lifespan.
*Please note that RenoAssistance doesn’t currently have roofers specialized in installing slate shingles, clay tiles, or cedar shingles.
Best roofing materials for flat roofs
Commercial and rental buildings usually have a flat roof. While they’re prone to leakage, they are built using different materials and have different maintenance requirements. Here are some flat roofing options available on the market.
Elastomeric or modified bitumen membrane
Elastomeric (or modified bitumen) membranes normally have two layers: the membrane itself and a granulated surface finish. The finish gives the roof a number of advantages, such as resistance to impacts, tears, and UV rays. The finish is hot applied, and the seams are fusion welded. Make sure your contractor has the right insurance coverage for using an open flame.
While an elastomeric membrane can be installed in the winter, scheduling your project during this season will make your project cost significantly more. Moreover, while a hot-applied elastomeric membrane may be expensive, it does have a longer lifespan than other flat roof material options.
White roof (elastomeric membrane)
Made with a white elastomeric membrane, white roofs reflect the sun’s rays instead of absorbing them. This is a major advantage: heat is one of the leading factors of elastomeric membrane degradation. Moreover, white roofs not only help prevent buildings from heating up but also combat the urban heat island effect. They resist inclement weather better than traditional membranes and can also be recycled.
TPO membrane (vinyl)
Thermoplastic polyolefin (TPO) is a single-layer reflective roofing membrane made from polypropylene rubber and polymerized ethylene-propylene. Similar to elastomeric membranes, the joints are normally fusion welded.
TPO is easy to maintain and install. Since it comes in large panels, it has fewer seams than other roofing materials, which cuts labour costs significantly. Moreover, TPO membranes are remarkably durable – they’re resistant to tears, wind, impact, bacteria, humidity, and perforation.
EPDM roofing (thermosetting plastic) is made from ethylene, propylene, diene, and monomer and installed in a process similar to that for TPO. EPDM resists rot, UV rays, fire, cold, vapour, and temperature variations, all properties that ensure it has a very long lifespan. This material requires little maintenance and is an excellent long-term investment.
Asphalt and gravel
An asphalt and gravel membrane is a traditional roofing material comprising several layers of overlapping bitumen felt covered with liquid asphalt. However, we recommend using a higher quality material that is less harmful to the environment. Several Montreal districts have banned this roofing material, and RenoAssistance’s roofing experts advise against using asphalt and gravel for your roof. There are many problems associated with this material: it tends to dry and crack under the heat of the sun; the gravel blocks drains, causing water infiltration; and the water that pools on its surface causes premature wear. We recommend a white elastomeric roof instead.
It’s possible to install a rooftop patio on a flat roof, but first you need to determine if the building structure can support the extra weight. To do that, you’ll need to consult a structural engineer and then get a permit. Keep in mind that the roof underneath must be watertight and that there are significant maintenance costs that come with a rooftop patio. That said, it has many benefits: it reclaims space, gives you a great location for a small garden, and provides you with the perfect place to relax outdoors in the summer!
Eco-friendly roofing options
An eco-friendly roof meets many criteria for respecting the environment and is available as an alternative to traditional asphalt shingles or tiles. It’s an integrated, multi-level system comprising underlayment, a waterproofing membrane, a root barrier, and a drainage system. If you want to be more mindful of the environment, you have two options.
According to Water Canada, green roofs provide many ecological, economical, and social benefits, such as rainwater management and reducing the urban heat island effect. There are two main types of green roofs: extensive and intensive.
Extensive green roof
An extensive green roof is lighter, more affordable, relatively easy to maintain, and has little biodiversity among the plants grown on it. This type of roof usually has limited access, so it’s best to avoid planting a large variety of species as it would need more upkeep.
Intensive green roof
An intensive green roof has a deeper growing medium layer for holding plants, which requires a solid support structure. This makes it a little more expensive than an extensive green roof but has the benefit of greater biodiversity.
A green roof has numerous benefits: it increases property value, blocks all UV radiation, reduces heat loss and gain (thereby lowering energy costs), and can even slow the spread of a fire to the roof. When the waterproofing membrane reaches the end of its useful life and needs to be replaced, the entire plant covering will have to be removed to access it.
The biggest financial investment is the installation itself, so be sure to request a certificate for your green roof for your insurance company if you decide to build one. You can also apply for the Canadian Greener Homes Grant to help fund your project.
Blue roofs are an incredible new concept in the roofing industry – they’re designed to collect rainwater to reduce the demands on the municipal sewer system. In areas with high rainfall, they can even reduce the risk of flooding. They’re generally installed on industrial or commercial buildings and can help keep the structure cool, thereby reducing air conditioning costs.
The base of a blue roof comprises standard insulation underneath a waterproofing membrane and a water barrier. An empty space to hold (and drain) the accumulated water sits on top of the base. This space is then covered by a permeable substrate and an outer surface.
It’s also possible to install a combination of both eco-friendly options: a blue-green roof. This roof performs the best in terms of water retention and management.
Overall, blue roofs are tricky to install and maintain and add considerable weight to the structure. If you’re thinking of getting one, you’ll need an engineer to determine if your building can support the weight.
Solar panels absorb the sun’s rays and use them to produce heat or energy. There are two main types: solar thermal panels (for heating water usually) and photovoltaic panels (for electricity). In both cases, their output depends on the amount of energy they absorb.
Solar panels are effective and affordable and have a long lifespan. They have less of an impact on the environment than natural gas, oil, coal, propane, and gas. If you’re thinking of installing solar panels, be sure to apply for the Canada Greener Homes Grant – it’ll help fund your eco-friendly project. Unfortunately, RenoAssistance does not have any Verified Contractors who can install solar panels at the moment.
Roof renovation cost
Many different factors influence the cost of a roof renovation. For example, replacing a roof that has experienced normal wear and reached the end of its useful life will not cost the same as repairing a roof that’s been damaged by inclement weather. Your roof may require other work like structural repairs or need ventilation outlets replaced.
The complexity and slope of your roof will also influence the cost. Steep slopes incur higher costs because they’re more difficult to work on. The same is true of roofs with lots of sides and gables – they need more elaborate work, so prices tend to be higher.
Of course, large roofs will have higher costs because they need more labour hours and materials to complete. Season is also a factor: labour costs are higher in the winter. Here are the estimated costs of different roofing materials in the GTA.
TPO and EPDM
$13 to $18/sq. ft.
Multilayer (gravel and bitumen)
$13 to $18/sq. ft.
$23 to $30/sq. ft.
$25 to $43/sq. ft.
$36 to $50/sq. ft.
Note these prices do not include demolition, crane rental, scaffolding, parking permits, and street occupancy fees.
Lifespan of different roofing materials
The average lifespan of your roof depends on the material installed. As can be seen in the table below, some materials age more quickly than others. Certain factors can affect the lifespan of your roof, such as the weather, material quality, and the slope of your roof.
15 to 25 years
TPO and EPDM
25 to 30 years
Multilayer (gravel and bitumen)
15 to 30 years
20 to 30 years
75 to 150 years
How does slope affect the lifespan of your roof?
The average lifespan of your roof depends on the material installed and the steepness of the slope, which is measured as a ratio of an increase in roof height over 12 inches of length (a flat roof has a ratio of 0:12). However, a standard slope ranges from 2:12 (two inches of height over twelve inches of length) to 4:12.
A normal slope (2:12 to 4:12) will not affect the lifespan of your roof, though a slope ranging from 5:12 to 9:12 will shorten it. A steeper slope makes roof renovation more difficult for the workers, as they often have to set up a scaffold for their safety.
A properly maintained flat roof has a standard lifespan.
What other factors affect the lifespan of a roof?
The lifespan of your roof depends heavily on how well you maintain it, so be sure to get it inspected twice a year. Branches falling from nearby trees could weaken or damage your roof, which would then have to be repaired. Weather conditions could shorten the lifespan of your roof as well. A pile of leaves could interfere with rain runoff. Hail could damage your roof, while strong winds could tear off shingles. What’s more, leaks in the roof could be worsened by snow, which constantly exposes your roof to humidity. Squirrels, birds, racoons, and other animals could shorten the lifespan of your roof if they find their way into the attic.
To ensure your roof lasts for its entire lifespan, you’ll need to do a few things to keep it in tip-top shape.
Conducting a roof inspection
To ensure your roof is well maintained, we recommend inspecting it twice a year: just before the frost and after the spring thaw. These inspections will help you notice potential issues like paint bubbles on the ceiling (caused by water leaks) and curling shingles (caused by strong winds). Remove debris, branches, or leaves that could damage or block drains or eavestroughs. Look for spots, organic matter, and mould. Make sure that water does not pool on the roof for more than 48 hours after a heavy rainfall.
Be sure not to overlook the attic. A smelly attic could be a sign of humidity. We recommend checking for fungus, mould, and signs of water infiltration. Every part of the roof structure must be in its proper place and in good condition. Also check that the trusses (part of the roof structure) have not become unstable and pose a risk of collapse.
How to maintain your roof
Here are a few things you can do to help maintain your roof.
- Remove any leaves or debris on your roof. They can block drains.
- Clean off any moss or algae that you see using a garden hose and/or roof cleaner. Over time, they can weaken the structure of a shingled roof.
- Repair damaged eavestroughs. They can cause water leaks in the basement and premature soil erosion.
- If you have a chimney, consider installing a rain diverter or cricket. It’ll help make the rain flow on either side of the chimney instead of letting it accumulate behind it.
Common roof problems
There’s a good chance that your roof will experience different problems over its lifespan. One of the most common issues is water leaking in through the roof. Sometimes leaks can be easy to spot: humidity stains may be visible in the middle of a wall or on the ceiling, paint may blister and bubble, wallpaper may peel off, or water might collect on the floor near a wall. Other times, they might be invisible. Since water can take many different paths into your home, you might need a thermal imaging inspection done to make sure you’re in the clear.
Damaged flashing can also cause leaks. Flashing protects the fittings and sealing joints of your roof from water accumulation; if it gets damaged, stagnant water may leak into the layers under the membrane and cause blisters to form. That said, this can also be caused by high humidity or a poorly installed membrane. Inclement weather can rip off poorly installed flashing or membranes, causing water to leak into the attic and fissures to appear in the roof.
Ventilating your roof
To prevent condensation, your attic from overheating, and your roof covering from premature wear, you must ensure your roof is adequately ventilated. Good ventilation not only prolongs the lifespan of your shingles and roof structure, but it also reduces the chance of mould and lowers the risk of long-term damage from ice dams. Some common signs of poor roof ventilation are lots of ice dams on the edge of the roof during winter and an overheated house during the summer.
Water bubbles or blisters appearing on the walls in the spring are a possible sign that condensation is accumulating in the attic over the winter. Be sure to check your attic for spots, mould, strong and abnormal odours, peeling, and stains on the wood or insulation. If the ventilation is inadequate, you may have to add a drip diverter or vent cap, replace the soffits, or install new roof insulation.
Questions to ask your roofing contractor
So, you’ve decided to redo your roof, have chosen your roofing materials, and are ready to begin your project. To ensure that the work is done properly and avoid future problems, here’s a list of questions to ask a potential roofing contractor.
- Do you have a licence? In Quebec, a contractor must hold the appropriate RBQ licence. In Ontario, you can ask your contractor if they have a Certificate of Qualification for their non-compulsory trade.
- Do you have contractor liability insurance? Make sure your contractor is insured so that you’re covered in case of injury or property damage. Take down their insurance certificate information and call up the company to see if it’s still valid.
- How long have you been in business? Ask the contractor how long they’ve been in business for and double check with ServiceOntario for Ontario-based contractors or le Registraire des entreprises for Quebec-based contractors.
- Who are your main suppliers? If the contractor has been purchasing their supplies from the same companies for a long time, it means they pay their suppliers well and they have a good business relationship.
- What type of warranty is offered for the roof? Make sure the warranty applies to the required work. Also check and see if the warranty covers labour, materials, or both.
- How long will the work take? Ask how long the work will approximately take and get them to lay out a detailed timeline for more complex projects. This way you can check in on the contractor’s progress and see where they’re at.
- Is there a chance that the cost will go up before the project has been completed? Avoid unexpected surprises and ask the contractor if they foresee any issues that could cause the price to go up.
- Who will be my main point of contact? It’s best to deal with one designated person; it’ll prevent misunderstandings and communication issues.
- What are the terms of payment? Be sure to put together a detailed payment schedule with your contractor and include these terms in your contract.
- What precautions will you take during the work and is debris disposal included in the contract? A good contractor wants to minimize potential risks and damage to your home during the renovation process, so ask them how they’ll go about it. Also, be sure to ask about debris disposal – it’ll save you some extra time and money.
Choosing the right contractor can be stressful, so if you want to save a lot of time and frustration, let RenoAssistance handle it. We’ve vetted all of our contractors, so you don’t have to. Just tell us about your project and one of our dedicated Advisors will get you up to three quotes, at no cost or obligation. Then you can talk to each of our Verified Contractors and pick the best one for your renovation.
Roof installation process
While installing a new roof is a relatively straightforward process, there are many steps involved. Both you and your contractor will need to prepare a few things before you start.
Preparing the work area
Although the contractor will carry out all the work, you should prepare your property beforehand. Keep in mind that roofing work can cause vibrations inside your home. Here are a few things you can do to get ready for your roof replacement project:
- Make sure the contractor has enough space to work
- Have parking nearby for the workers
- Empty your attic or cover anything inside it with plastic sheets to protect it from dust falling from the ceiling
- Make your patio and the entryways into your home available to the workers
- Identify the plants in your garden that need special protection and cover them, as work on your house will certainly have an impact on the landscaping of your yard
- Mow the lawn before the work begins to make it easier to find debris
- Remove any wall decorations that could fall off due to vibration
- Explain the danger posed by debris to the rest of the family, especially your children
- Make sure the workers have access to an outdoor electrical outlet
- Warn your neighbours about the noisy work that will soon begin
Once these preparations have been made, the workers will be able to go about their business efficiently, and your house will remain safe during the project.
Deconstructing your old roof
After the old roofing material has been removed, any structural work needed will be done. Then, the new materials will be installed. Doing things in this order makes it possible to detect hidden problems.
Installing primary components
The primary components (waterproof membrane and various underlayers to protect the roof from inclement weather) must be in place before the roofing material can be installed.
A waterproof membrane is installed beneath the roofing material and is designed to protect the vulnerable points on the roof from damage caused by water or ice.
Eave protection helps prevent water infiltration.
A fire-resistant barrier must be installed to slow the spread of a fire.
Mechanical outlets and ventilation intake openings
Mechanical and ventilation outlets must be installed. Mechanical outlets on the roof serve as an exhaust for the bathroom fan, vent hood, dryer, or indoor ventilation system, while ventilation intake openings allow for air circulation in the attic.
Roof support structure
The roof support structure includes trusses, rafters, and all the other components that make up the frame. The roofing material is nailed, screwed, or glued onto these elements.
Different types of flashing are found on your roof. Generally, flashing is needed at critical points where water could infiltrate and cause damage to the roof, such as at the junction between two roof surfaces (e.g., the chimney and the roof, the ventilation system and the roof).
You’ll find the ridge board at the peak of your roof – it’s where all your rafters meet!
The soffit is the finished side under the eaves, which should have intake openings to allow air to circulate in the attic. If the soffit is poorly maintained, rodents or other animals could enter the house.
A plumbing vent is the opening in the roof deck through which a pipe or tube is passed to allow air to circulate.
Roofing material installation
Once the primary components are in place, the roofing material may be installed. This step consists of attaching your choice of roof covering to the frame.
Verification and cleanup
Once the work has been completed, you should walk around your property looking for any debris the contractor may have overlooked. Also, inspect the roof to ensure the work was done properly. Don’t hesitate to speak to your contractor about any problems you notice or ask them questions about the work done. And when everything is in order, don’t forget to pay them!
Average time for changing a roof
If the frame doesn’t need to be touched, the work will take a minimum of one day, two if a few repairs need to be done to the frame and the surface area of the roof is under 540 sq. ft. Only an experienced roofer can give you an accurate timeline estimate based on your type of roof. The duration of the work will depend on the size of the roof and the nature of the work. The installation technique needed for your roofing material helps determine how long the installation itself will take. For a roof replacement, the time for deconstructing the old roof must be included. Basically, the duration is determined by the size of the roof, the work to be done, and the number of contractors at the work site.
Things to avoid when installing a roof
Now that you understand the process of installing a new roof, it’s time to go over some things to avoid during your roof renovation.
- Don’t install new shingles over old shingles. Instead, replace them.
- Don’t leave ventilation issues unaddressed. A poorly ventilated roof can cause condensation build up and increase heating/cooling costs.
- Don’t press down on the insulation. It’ll cause heat loss through the roof.
- Don’t leave air pockets. Instead, fill the space completely with insulation.
- Don’t leave any structure unprotected from rain and wind.
A quality warranty applies when you have your roof built or renovated. Consumers’ rights are protected by the Consumer Protection Act and Civil Code.
Register the warranty
The warranty is ensured by the contractor. Keep your invoice in a safe place in case you ever need to make a claim; it’ll prove the work was done if a problem arises.
What is covered by the manufacturer’s warranty
Your best protection is your contract. However, there are warranties that protect you should either the contractor or manufacturer be at fault. Under the Civil Code of Quebec, the contractor is responsible for a year after the date the work was accepted should any issues arise due to poor workmanship. The contractor is also responsible for five years for any loss resulting from a construction defect. The Consumer Protection Act holds the manufacturer responsible for guaranteeing usage of the product for a reasonable time and that it be free from hidden defects.
Our no-cost Renovation Guarantee
RenoAssistance offers an additional renovation guarantee at no cost to any client that hires one of our 53-point Verified Contractors to complete their renovation or construction project. That said, certain conditions do apply. Here’s what’s covered:
- Deposit reimbursement, up to 25% of the contract value (max: $25,000)
- Renovation completion, up to 25% of the contract value (max: $25,000)
- Apparent defect repairs, up to 10 days after the work has been completed (max: $10,000)
- Latent defect repairs, up to one year after the work has been completed (max: $10,000)
Please note that this warranty is offered in Quebec and only applies to non-commercial residential projects.
Nowhere to go but up
Your roof is a critical part of your home – if there’s a problem with it, it can damage the rest of the interior. Many home-related issues can be avoided by having a well-built roof, so be sure to perform routine maintenance and inspections to extend its lifespan. And if you’re looking to redo your roof, check out the different types of materials on the market, their costs, and their pros and cons.
Don’t hesitate to ask your roofer questions to ensure that you hire the right person. For example, ask about how they’ll manage debris, if they have insurance, and what the manufacturer’s warranty includes.
Of course, if you do business with RenoAssistance, we’ll support you throughout the roof replacement process, starting with finding you up to three Verified Contractors for your project. We can help you if you encounter any difficulties, answer your questions, and make sure your new roof is of the highest quality.