Gas fireplace venting done by the manual in Audubon Park

Air space around the vent pipe

Vent pipe needs open air around it. In one maker's chart, horizontal pipe keeps 3 inches of space above it and 1 inch below and to each side until it reaches the outside wall, and the pipe keeps a 1 inch gap on every side where it passes through that wall and wherever it runs vertically.

The same maker warns that stuffing insulation or anything else into those gaps can drive temperatures up and create a fire hazard. Our crew checks every section it can reach for framing, wiring or insulation crowding the pipe and lists any correction in the estimate.

• 3 inches above horizontal runs in that manual
• 1 inch at the sides and bottom
• 1 inch all around at walls and on vertical runs

Offsets and horizontal runs in B-vent

Natural draft needs the pipe to keep climbing. One B-vent fireplace manual keeps every horizontal run shorter than half the total vent height, measuring pipe center to pipe center, and wants each run to rise at least 1/4 inch per foot, never level and never downhill.

Too much offset is also the first cause in that manual's list for poor draft. Our pros check the slope of every horizontal section they can reach and compare the total offset with the height of the whole vent.

Moving the termination during a remodel

Relocating a vent cap counts as a new installation of the vent rather than a small extension. The new route has to fit the manual's vent graph, stay inside the elbow and length limits and end at a spot that meets every termination clearance.

Our specialists plan the route before the walls are opened in Audubon Park, list the wall, roof and finish work on separate lines and show you where the new cap will sit. Nothing gets cut until you have approved that plan in writing.

A new roof around a vertical vent

Reroofing disturbs everything at a vertical gas vent, from the flashing to the storm collar to the cap. Section 503.6.7 of the Florida fuel gas code calls for gas vents to pass through a roof flashing, roof jack or roof thimble and end with a listed cap or listed roof assembly.

A generic cap from the roofing supply is not always the listed one. Our crew checks the cap, the collar and the height above the new roof surface and replaces what does not belong.

Nothing but gas in a direct-vent firebox

A gas fireplace is built for one fuel. One direct-vent manual says not to use any solid fuels in it, naming wood, coal, paper and cardboard, and not to use it to cook or burn paper or other objects.

Debris and ash from anything else can block burner ports and air passages and change how the vent works. If our crew finds signs of burned paper or other material in the firebox, we clean it out and explain what it may have done to the burner.