The 10-foot/2-foot Rule Explained
For additional information regarding the 10-foot /2-foot rule, download this PDF file to get detailed information and calculation diagrams.
This rule is frequently misunderstood or ignored, and many people have drafting problems with their fireplaces for this reason. This rule is fairly simple, however, and must be followed in every vented fireplace installation.
National Fuel Gas Code, ANSI Z223.1, Section 10.5.2.1, states the rule: “A chimney for residential-type or low-heat gas utilization equipment shall extend at least 3 ft. (0.9 m) above the highest point where it passes through a roof of a building and at least 2 ft. (0.6 m) higher than any portion of a building within a horizontal distance of 10 ft. (3 m).”
The basic rule is this: the bottom of the vent termination must clear the roof penetration point (the upper edge) by at least 3 feet; further, the bottom of any fireplace vent termination must clear anything within a 10-foot radius by at least 2 feet. This includes the peak of the house, parapet, dormer, chimney, or spire.
Tips For Good Fuel
Firewood should be cut, split, and stacked in an open area in the early spring to be ready for burning the next heating season. Very hard woods like oak may take longer to season, and seasoning in damp maritime climates may take a little longer than the summer months.
The firewood pieces should be cut to a consistent length, about 75mm (3 inches) shorter than the largest horizontal firebox measurement.
Firewood should be split into a variety of sizes, ranging from about 75mm (3 inches) to no more than 150mm (6 inches) across the largest cross-sectional dimension.
Stack the firewood on rails or poles to raise it slightly off the ground. Separate the rows by at least a pace or two to allow air circulation to carry away moisture.
Any wood species can be burned, although some are less desirable because they are hard to split or have sticky sap in their bark.
Scrap lumber and packing skids can be burned if the pieces are not painted or coated.
Garbage of any kind
Treated, painted, or coated wood
Plywood and particle board
Fine papers, coloured papers and cardboard
tips for smoke-free fires
A good wood fire doesn’t produce much smoke because the tarry droplets and gasses that would become smoke are burned before they leave the firebox. The easiest way to achieve smoke-free fires is to use an advanced combustion stove like those certified by the US Environmental Protection Agency. (EPA approved) But even if you don’t have a clean burning stove, furnace, or fireplace, there are some things you can do to reduce the smoke from your fires.
Burn only seasoned wood. Wet wood makes smoky fires.
Burn the wood in cycles. A cycle starts with loading some wood on a bed of charcoal and ends when about the same size charcoal bed remains. Don’t expect perfectly steady heat output. In most appliances, the wood burns best in cycles.
Make sure that each load of wood flames brightly until it is reduced to a coal bed. Never let a fire smoulder.
In mild weather, split your wood smaller and build smaller fires using at least three, and preferably five or six, small pieces. One or two large pieces of wood in the firebox will smoulder.
Gauge your progress by checking your chimney. If there is smoke, something is wrong.