Maintain Clearances
The most important aspect of safety while designing your venting system is maintaining clearances to combustible materials. Failure to maintain proper clearance is a severe fire hazard. Remember to use clearance shields whenever required. See the chart below:| Attic Insulation Shield | Passing thru an attic |
|---|---|
| Firestop | Passing thru 2nd story |
| Radiation Shield | 2nd story + Attic Space |
| Wall Thimble | Passing thru a wall |
| Mortar Sleeve | Passing thru masonry wall |
| Ceiling Support | Passing thru ceiling |
Reference the guide below for clearances:
Simpson/Duratech
| Simpson | Duratech | 2 Inches |
|---|---|---|
| Simpson | Pellet Vent | 3 Inches |
| Simpson | Pellet Vent Corn | 3 Inches |
| Simpson | B Vent | 2 Inches |
| Simpson | SS Liner | 2 Inches |
| Simpson | AL Liner | 2 Inches |
| Simpson | Stove Pipe (Single Wall) | 18 Inches |
| Simpson | Stove Pipe (Double Wall) | 8 Inches |
| Simpson | Direct Vent | 3 Inches |
Metal-Fab
| Metal-Fab | Class A/ UL-103/HT | 2 Inches |
|---|---|---|
| Metal-Fab | Class A 5-7" Dia | 1.5 Inches |
| Metal-Fab | B Vent | 2 Inches |
| Metal-Fab | Pellet Vent | 3 Inches |
| Metal-Fab | SS Liner | 2 Inches |
| Metal-Fab | AL Liner | 2 Inches |
| Metal-Fab | Stove Pipe (Single Wall) | 18 Inches |
| Metal-Fab | Stove Pipe (Double Wall) | 8 Inches |
| Metal-Fab | Direct Vent | 3 Inches |
| Metal-Fab | Special Gas Vent | ? |
Metalbest
| Metalbest | Class A | 2 Inches |
|---|---|---|
| Metalbest | Pellet Vent | 3 Inches |
| Metalbest | B Vent | 2 Inches |
| Metalbest | Flexible Liner | 2 Inches |
| Metalbest | Stove Pipe (Single Wall) | 18 Inches |
| Metalbest | Stove Pipe (Double Wall) | 8 Inches |
| Metalbest | Direct Vent | 3 Inches |
Support Brackets:
Support brackets are required when running pipe vertically along a wall, or additionally above the roof.
| Wall Support Band | Every 5-7 Feet |
|---|---|
| Extended Roof Support | More than 5 ft Above Roofline |
| Elbow Strap | Always in an offset |
| Firestop | When passing thru 2nd story |
Check Local Code:
Remember to contact your local code office before proceeding with your installation. Some counties have abnormal requirements for clearances, and even types required for your appliance.
Some clearances that may differ from county to county are:
- Clearance to windows/doors/air inlets
- Clearance from the ground
- Clearance from a sidewalk/path
- Minimum roof termination distance (How far the pipe is above)
Some type requirements that may differ:
- Triple-wall pipe may be required where double-wall is normally sufficient.
If you choose to ignore local code requirements, please keep in mind that your installation will not pass general inspection, and there could be potential fire hazards.
