Fireplace Opening Size

This is a wonderful flue sizing tool.

Fireplace opening size.

Do not confuse a small open fire with the builder s opening small open fires are often built within the builder s opening and excavation will reveal the larger recess. This part of the fireplace is called the throat. I d hoped to have as big a fireplace as possible up to 60 wide. These are exterior measurements.

I had another question regarding fireplace size. Fireplace opening and flue size in creasing the chimney height in creases the amount of draft. To provide adequate draft and safe venting of combustion products the chimney flue for a fireplace has to be adequate in size or cross sectional area. The opening width of this firebox is 42 3 4 at the face of the unit and the height is 35 1 4.

Building codes typically require a minimum flue size expressed in terms of cross sectional area in relation to the area of the fire place opening. In general the flue can be 1 10th to 1 12th as large as the opening. I checked out your specifications page and was hoping for some advice regarding fireplace size. Fireplace flue size specifications relation of fireplace size to flue opening dimensions table of required chimney flue size and flue dimensions for masonry fireplaces.

The size of fireplace insert you require is related to the size of your existing masonry chimney. Interior measurements also need to be taken. The most common case is 1 10 of the fireplace opening area but with a minimum size specified. This article series provides information about masonry fireplaces.

How high up should the damper be above the fireplace opening. It s important to have a builder who knows how a fireplace works and makes sure the fireplace opening and the flue size are the right match to create excellent venting. When a home is built with a masonry fireplace there is a huge range of possible sizes. The bottom of the damper should be a minimum of 8 inches above the top of the fireplace opening.

Since almost all fireplaces are different your exact opening size will determine the appropriate flashing or surround to accompany your insert. To properly size a flue you must use a nomograph. The flashing or surround will cover the area where the insert meets the edge of the preexisting fireplace and cover any unsightly gaps.