Are you thinking about adding a roof access hatch, a skylight, or both? The right choice depends largely on the type of roof you have: a flat roof and an asphalt shingle roof have different installation, waterproofing, and structural requirements. Here’s what you need to know before making your decision, including safety considerations, explained simply below.
Key points to remember
- An access hatch eliminates the need for an outdoor ladder, which is more dangerous in winter.
- Flat roofs and shingle roofs have different installation and waterproofing requirements.
- A hatch combined with a skylight adds natural light without sacrificing access.
- Waterproofing around the opening is the most critical aspect, regardless of the type of roof.
- Safe access to the roof becomes important as soon as regular work at heights is planned.
Why Install a Roof Access Hatch?
On many buildings, access to the roof is still via an exterior ladder—a method that is impractical and downright dangerous during Quebec winters. An access hatch, on the other hand, allows you to reach the roof safely from the inside, which simplifies maintenance, snow removal, or routine inspections of equipment installed on the roof (air conditioning units, chimneys, solar panels).
Access Hatch on a Flat Roof vs. a Shingle Roof
Both types of roofing can accommodate an access hatch, but the requirements differ.
On a flat roof, the opening is integrated into a horizontal surface covered with a membrane (elastomer, TPO, or EPDM). The edge of the hatch must be raised to prevent standing water from reaching the seal—a particular concern with this type of roof.
On an asphalt shingle roof, the skylight is typically installed on a sloped surface. Water flows more naturally this way, but the flashing around the opening requires more precision: the hatch must be integrated into the existing rows of shingles to prevent any water from seeping under the roofing material.
In both cases, the frame must be made of sturdy material—aluminum or galvanized steel being the most common choices in Quebec—to withstand freeze-thaw cycles and the weight of accumulated snow.
Combining an access hatch and a skylight
It is possible to combine the access hatch and the skylight into a single opening: the hatch then serves both as an access point and as a source of natural light. This combination is increasingly in demand, both in new construction and in renovations, since it reduces the need for artificial lighting while providing convenient access to a patio or usable outdoor space.
However, the glazing used must be specifically designed for access purposes, not just to let in light: it must be strong enough to withstand snow loads while remaining safe for regular use.
Safety: What You Need to Know About Accessing the Roof
Beyond comfort, access to the roof raises a real safety concern. The CNESST reminds us that whenever there is a risk of falling more than 3 meters, protective measures must be put in place, whether in the form of a guardrail or an equivalent device. A properly positioned access hatch, combined with an anchor point if regular work is planned on the roof, reduces this risk compared to an improvised exterior ladder.
Reference Chart: Which Solution Is Right for Your Situation?
| Situation | What it means | What to do |
| Flat roof, occasional access | Membrane to be protected around the opening | Hatch with a raised rim and flashing adapted to the membrane |
| Shingle roof, occasional access | Flashing to be integrated into existing rows | Installation by a roofer to ensure waterproofing |
| Need for natural light in addition to access | Two functions to combine in a single opening | Skylight hatch with snow-load-resistant glazing |
| Frequent access for equipment maintenance | Risk of falling to be assessed | Provide an anchor point or guardrail depending on the height |
What to Do Before Installing Your Access Hatch
If you simply need occasional access for general maintenance, a standard access hatch in the right location is usually sufficient. If the roof is frequently accessed for maintenance of mechanical equipment or solar panels, it’s worth evaluating fall protection needs at the same time. In any case, a professional must verify thestructural integrity and watertightness of the opening before installation, particularly on an existing roof where the condition of the deck is not always visible.
Long-lasting access, a roof that stays watertight
A properly installed access hatch makes roof maintenance easier for years to come—provided the seal around the opening is installed correctly. Whether you’re looking for simple, safe access or a combination with a skylight, the choice of materials and the quality of the installation make all the difference.
Our team can inspect your roof—whether it’s flat or made of asphalt shingles—and recommend the solution best suited to your structure and your needs.
Contact Us for more information
FAQ
Can an access hatch be installed on any type of roof?
Yes, but the installation method varies. A flat roof requires a raised edge to manage standing water, while a shingle roof requires flashing integrated into the existing rows.
Can an access hatch replace a skylight?
Yes, several models serve both purposes, featuring durable glazing designed for regular access rather than simply as a fixed window.
Is an anchor point needed in addition to the hatch?
It depends on how often the roof is accessed and the risk of falling. An anchor point becomes necessary as soon as regular work on the roof is planned.
What frame material is recommended in Quebec?
Aluminum and galvanized steel are preferred for their resistance to freeze-thaw cycles and the weight of accumulated snow.
Could an access hatch cause water to seep in?
Only if the installation or flashing is done improperly. Professional installation minimizes this risk, whether the roof is flat or shingled.
