The work
What patio doors actually involves
Sliding or hinged, and what each needs from the opening
Sliding doors run on rollers in a track and take no space to open, which suits a small room or a tight terrace. Hinged doors seal better, because a compression seal beats a sliding one, and they need clearance to swing.
Both are large glass areas in a structural opening, which means the header above has to be right and the sill below has to shed water.
Sliding doors need their tracks kept clean and their rollers adjusted, and a door that has become hard to slide is usually rollers rather than the door. It is a cheap service that people leave until something breaks.
Glass
Safety glazing is required, and the coating is worth choosing
Any large glazed door is required to use safety glass, and beyond that the coating on it is a decision rather than a default.
Low-emissivity coatings come in variants tuned for keeping heat in or keeping solar gain out, and the right one depends on the climate and which direction the doors face. West-facing glass in a warm climate is the clearest case for the second.
It is also worth asking about the spacer between the panes. Warm-edge spacers reduce condensation at the bottom of the glass, which is where large doors show it first.
Failure points
Two things that go wrong
The header above the opening
“Does the structural opening change, and if so who is specifying the header?”
Widening an opening or replacing a unit with something larger puts load on a header that may need to change. That is structural work with its own permit and engineering, and it is a very different project from swapping like for like.
Drainage at the sill
“How does the sill drain, and is the outside level low enough for it to work?”
Patio door sills have weep channels that let water that gets into the track drain out. Blocked, badly installed or set below the outside level, they deliver water into the floor instead. It is the main reason these doors leak.
Before you book patio doors
How we rank →Six checks, in the order they save you the most. None of them takes longer than a phone call, and the first one is the reason two quotes for the same job can be a thousand apart.
Common questions about patio doors
Who handles patio doors?
Patio doors is handled by window companies. Not every company in the trade takes this work on, so each ranking lists the services a company genuinely performs rather than everything it advertises.
What should I ask before booking patio doors?
Ask what the quote includes and excludes, who is doing the work, whether a permit is needed and who is pulling it, and what the workmanship warranty covers. Get the answers in writing before anyone starts.
How do I compare quotes for this?
Put them on one sheet line by line. Differences in price almost always turn out to be differences in scope, material grade or warranty length rather than margin.
Is patio doors priced separately from the rest of the job?
Usually it is a line inside a larger quote rather than its own invoice, which is exactly why the exclusions matter. Ask for it itemised so you can compare that line between companies instead of comparing two totals.
For windows and doors
Do you offer patio doors?
Claim your profile so the services you actually perform are the ones recorded here, alongside your licence, hours and coverage. Neither claiming nor advertising buys a ranked position.