Concrete Encasement Calculator

This concrete encasement calculator nets out what estimators often forget: the pipe. It computes the rectangular encasement prism along the run and subtracts the cylinder the pipe displaces — the true concrete volume for pipe and duct encasement.

in
in
in
ft
5%
$ per yd³

Come usare questa calcolatrice

  1. Inserisci le tue dimensioni — piedi per le lunghezze, pollici per lo spessore.
  2. Regola le opzioni — percentuale di sfrido, dimensione del sacco e il prezzo locale del calcestruzzo.
  3. Leggi i risultati — volume, sacchi, peso e costo si aggiornano in tempo reale mentre digiti.

La formula

Net volume = (width × height × length) − π × (pipe Ø ÷ 2)² × length

Esempio svolto: An 18 × 18 in encasement over 50 ft around a 6 in pipe: (1.5 × 1.5 × 50) − π × 0.25² × 50 = 112.5 − 9.8 = 102.7 ft³ ≈ 3.8 yd³.

Pipe encasement specs typically call for 6 inches of concrete cover on all sides, which sets the prism: pipe diameter + 12 inches each way. A 6-inch pipe gets an 18 × 18 inch encasement, as in the example.

For multi-conduit duct banks, subtract each conduit: run the calculator once per conduit size and deduct the additional displacements, or conservatively ignore small conduits (a 2-inch conduit displaces only 0.022 ft³ per foot).

Encasement pours flow under and around the pipe — strap or block pipes against flotation before the pour. Empty plastic pipe floats energetically in wet concrete.

Domande frequenti

Domande comuni sulla concrete encasement calculator.

How much concrete to encase a pipe?

Encasement cross-section (width × height) × run length, minus π r² × length for the pipe. The calculator handles both terms.

How much cover does encasement need?

Typically 6 inches of concrete on all sides of the pipe — check the utility's spec; some require 4 inches, telecom banks often 3.

Do I subtract small conduits?

Under 2 inches diameter, the displacement is usually within waste allowance. Above 4 inches, subtract — a 6 in pipe displaces nearly 0.2 ft³ per foot.

Why did my encasement pour float the pipe?

Buoyancy — concrete is 2.4× denser than water. Anchor or weight pipes at 5–10 ft intervals before pouring.