Firestop Penetration Calculator

Calculate annular space, sealant volume, and packing depth for through-penetration firestop systems.

Opening diameter (in)

Penetrant diameter (in)

Wall/floor thickness (in)

Required fire rating (hrs)

Number of penetrants

Tab to move between fields

Annular space (sq in)

25.13

Sealant volume (fl oz)91.9

Fill ratio (%)11%

Mineral wool depth (in)5

Material cost ($)$46.30

Total installed cost ($)$70.30

How to Use This Calculator

Enter Opening diameter (in), Penetrant diameter (in), and Wall/floor thickness (in).
Set Required fire rating (hrs) and Number of penetrants.
Review the Annular space (sq in) result.
Use Sealant volume (fl oz) and Fill ratio (%) (%) to inform your decision.

How the result changes with Opening diameter (in)

Opening diameter (in): Diameter of the opening in the fire barrier.
Penetrant diameter (in): Outer diameter of each pipe, conduit, or cable.
Wall/floor thickness (in): Thickness of the fire-rated assembly.
Required fire rating (hrs): Required hourly fire resistance rating (1, 2, 3, or 4 hr).
Number of penetrants: Number of pipes/conduits passing through the opening.

Annular space (sq in): Gap area between opening and penetrants.
Sealant volume (fl oz): Firestop sealant needed including 10% waste factor.
Fill ratio (%): Percentage of opening occupied by penetrants (max 40% typical).
Mineral wool depth (in): Minimum packing depth per ASTM E814.
Material cost ($): Estimated sealant and mineral wool cost.
Total installed cost ($): Materials plus labor estimate.

Identify Input Parameters
4 parameters
Opening diameter (in) = 6, Penetrant diameter (in) = 2, Wall/floor thickness (in) = 6, Required fire rating (hrs) = 2 = 5 input(s) provided
Calculate Annular space
Annular space
25.13 = 25.13
Calculate Sealant volume
Sealant volume
91.9 = 91.9
Calculate Fill ratio
Fill ratio
11 = 11%