The threshold is the small strip at the bottom of every patio door — but it determines water control, accessibility, and energy performance.
Three Common Threshold Types
- Standard threshold — 25–38 mm raised, best water resistance
- ADA / accessible threshold — max 13 mm raised, allows wheelchair access
- Recessed (flush) threshold — flat between interior and deck, modern look
Threshold Impact on Energy
A standard raised threshold has a built-in weatherstrip and excellent air seal. ADA-compliant thresholds can leak air more easily — they require careful installation and high-quality compression seals.
Water and Weather Control
Recessed thresholds need exterior drainage planning — the deck or patio surface should slope away from the door. In Quebec, this also means thinking about ice damming and snow accumulation.
When to Choose Each
ADA for aging-in-place or wheelchair households. Recessed for new builds with proper drainage planning. Standard for most retrofits and replacements. See our patio doors page for options.
Frequently Asked Questions
Can ADA thresholds work in Quebec winters?
Yes — with the right compression seal and exterior drain channel.
Are recessed thresholds more expensive?
Yes, typically 10–20% more due to drainage and installation complexity.
Can I add a threshold ramp to an existing door?
Yes — aftermarket aluminum ramps work for short-term accessibility.