Hearth and Home Technologies Montana-42, Montana-36 Chimney Height Requirements above roof line

MONTANA INSTALLATION INSTRUCTIONS

2.Chimney Height Requirements (above roof line)

a.Major building codes specify a minimum chimney height above the roof top. These specifications are summarized in what is known as the Ten Foot Rule. This rule states:

“If the horizontal distance from the side of the chimney to the peak of the roof is ten feet or less, the top of the chimney must be at least two feet above the peak of the roof, but never less than three feet in overall height above the highest point where it passes through the roof.

“If the horizontal distance from the side of the chimney to the peak of the roof is more than ten feet, a chimney height reference point is established on the surface of the roof a distance of ten feet from the side of the chimney in a horizontal plane. The top of the chimney must be at least two feet above this reference point, but never less than three feet in height above the highest point where it passes through the roof.” See Figure 8.

b.These chimney heights are necessary in the interest of safety but do not ensure smoke-free operation. Trees, buildings, adjoining roof lines, adverse wind conditions, etc. may create a need for a taller chimney should smoking occur.

3.Number of Sections Required

To determine the chimney components needed to complete your particular installation, follow the steps below:

a.Determine the total vertical height of the fireplace installation. This dimension is measured from the base of the fireplace assembly to the point where the smoke exits the termination cap.

b.Subtract the effective height of the fireplace assembly from the overall height of the fireplace installation (measured from the base of the fireplace to the bottom of the termination cap).

c.Refer to Table 2 to determine what components must be selected to complete the fireplace installation.

d.Determine the number of firestop spacers, stabilizers, roof flashing, etc. required to complete the fireplace in- stallation.

Figure 8 - Chimney Height

Table 2

HEIGHT OF CHIMNEY COMPONENTS

Chimney Stabilizer

SL11	43/4"
Firestop Spacers
FS538	0
FS540	0
Offsets/Returns
SL1130	14½"
Roof Flashing
RF570	0
RF571	0
Chimney Sections*
SL1106	43/4"
SL1112	103/4"
SL1118	163/4"
SL1136	343/4"
SL1148	463/4"

*Dimensions reflect effective height.

01/04 4039-150 Rev B 11