Gas Fitter Mosman | Licensed Gas Fitting

One gas rises. The other sinks.

Most gas safety advice is written for a single-level house where it does not much matter which direction a leak travels. On a property with rooms below the entry level it matters a great deal.

Natural gas, the kind that arrives through a meter from the street, is lighter than air. A leak rises and disperses upward, which is why high-level ventilation is what deals with it.

LPG, the kind that comes in bottles or a tank on the property, is heavier than air. It sinks. It finds the lowest point available and stays there: a lower-ground room, a cellar, a plant space, a boat shed, a stairwell that goes down rather than up.

So a leak that would dissipate harmlessly in a flat-plan house can pool in a low space here and remain. That is why we confirm which gas a property has before giving any advice at all, and why a room that seems well ventilated at head height can still be wrong for LPG.

Call 1300 381 569 Book a look

We confirm which gas firstThe safety advice genuinely differs
Low-level ventilation assessedWhere LPG actually collects
Compliance certificateIssued on every gas job, always
Licensed gas fitterNSW Licence 368473C, fully insured

Local gas guide

LPG, natural gas and low rooms in Mosman

Natural gas rises, LPG sinks

Natural gas is lighter than air and disperses upward. LPG is heavier than air and settles at the lowest point it can reach.

They are opposite behaviours, and almost all general gas advice quietly assumes the first one.

Which gas you have is easy to establish

Mains gas arrives through a meter connected to the street. LPG comes in cylinders or a tank on the property, with no street connection.

If you swap or refill bottles, it is LPG. We confirm it as a matter of course because the advice differs.

Low spaces change the risk with LPG

A lower-ground room, a cellar, a plant space or a downward stairwell is exactly where LPG will accumulate and stay.

A leak that would dissipate in a single-level house can sit in one of those and not disperse at all.

Ventilation has to match the gas

Low-level ventilation is what matters for LPG. High-level is what disperses natural gas.

A room that looks properly ventilated at head height can still be entirely wrong for LPG at floor level.

So the assessment is of the room, not the appliance

Whether an LPG appliance suits a particular low space depends on that space and its ventilation, not on the appliance's specification.

It is not a decision that can be made from a catalogue, and we will look rather than generalise.

What gas fitting costs in Mosman

Agreed before we start. These are indicative 2026 ranges. The Certificate of Compliance is included on every gas job and is never charged as an extra.

Leak test and make safe $200 – $450

Any hour. Isolated and made safe first, then diagnosed properly.

Ventilation assessment $180 – $350

For a lower-ground room or plant space, matched to the gas actually in use.

Appliance connection $250 – $550

Cooktop, oven, heater or bayonet onto an existing point, tested and certified.

New gas point or run $450 – $1,200

Priced on the route and what it has to pass through.

Certificate of Compliance included

On every gas job. Legally required, and never charged for here.

How a gas call-out runs.

Step 01

Licensed gas fitter attending a call-out in Mosman

Which gas, established first

Mains or LPG. It changes the safety advice and it changes where a leak would be.

Step 02

Pressure testing a gas installation in Mosman

Made safe, then tested

Supply isolated first on any suspected leak, then pressure tested to find where it is actually escaping.

Step 03

Assessing ventilation in a lower-ground room in Mosman

Ventilation checked where it matters

For LPG in any low space, at floor level rather than at head height.

Step 04

Issuing a gas compliance certificate to a Mosman customer

Certified and handed over

Tested again on completion and your Certificate of Compliance issued on the spot.

Gas fitting questions.

What Mosman locals ask us before booking a plumber.

Ask us yours Licensed plumbing van covering Mosman and the surrounding suburbs

I can smell gas. What should I do right now?

Stop reading and act. Do not touch a light switch, a power point or anything that could spark, and do not use a phone inside the building. Open doors and windows on the way out, turn the gas off at the meter if you can safely reach it, get everyone outside, and ring from outdoors. On a property with lower levels, go UP and out rather than down, because where the gas collects depends on which gas it is. We answer 24 hours.

Why does it matter whether it is LPG or natural gas?

Because they behave in opposite directions, and on a property with rooms below the entry level that matters a great deal. Natural gas is lighter than air, so a leak rises and disperses upward. LPG is heavier than air, so it sinks and collects at the lowest point it can reach: a lower-ground room, a cellar, a plant space, a boat shed, a stairwell that goes down rather than up. A leak that would dissipate harmlessly in a single-level house can pool in a low space and stay there.

How do I know which one I have?

Mains gas is natural gas and arrives through a meter connected to the street. LPG comes in cylinders or a tank on the property, and there is no street connection. If you are refilling or swapping bottles, it is LPG. If you have never thought about where it comes from and there is a meter at the boundary, it is almost certainly natural gas. We confirm it as a matter of course, because the safety advice differs.

What does that mean for ventilation?

That the ventilation has to suit the gas. Low-level ventilation matters for LPG because that is where it accumulates, and a room that appears well ventilated at head height can still hold LPG at floor level. High-level ventilation is what disperses natural gas. This is a genuine design question rather than a formality, and on a property with lower-ground rooms it deserves proper attention rather than an assumption.

Can I put an LPG appliance in a lower-ground room?

It depends entirely on the room and how it is ventilated, and it is not a decision to make from a catalogue. The combination worth being careful about is LPG plus a space with no low-level ventilation and no route out at floor level. We assess the actual room rather than giving a general answer, because the general answer is neither yes nor no.

Do I get paperwork?

Always, on every gas job, without asking. A Certificate of Compliance is legally required for gas work in NSW and it records what was done, that it was tested, and under whose licence. Keep it with the house papers, because insurers ask for it and so does anyone buying the property.

What does gas work cost in Mosman?

A leak test and make-safe is $200 to $450. Connecting an appliance to an existing point is $250 to $550. A new gas point or run is $450 to $1,200 depending on the route. A ventilation assessment for a low-level room is $180 to $350. The compliance certificate is included on every gas job.

Licensed Mosman plumber arriving with his tools

Get the gas work done in Mosman

Tell us whether it is mains gas or LPG, and whether the room involved sits below the entry level. Those two answers change the advice entirely.

Which gas confirmed first, ventilation assessed where it matters, and a Certificate of Compliance before we leave.

1300 381 56924/7 emergency line

[email protected]Non-urgent enquiries

Servicing Mosman & districtNSW Licence 368473C

Licensed gas fitting
across Mosman

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One gas rises. The other sinks.

Smell gas on a property with lower levels?