Figure below is a plan for a $3-$chamber septic tank.

Note:

a$.$ CHB vertical bars $0\mathrm{.}4m0.c.$; horizontal bars every layer.

b$.$ All inside walls shall be plastered finish

c$.$ Allow additional $0\mathrm{.}15m$ around perimeter for excavation

d$.2^{\text{'}\text{'}}$ thick gravel bed shall be compacted

e$.$ Manpower: $2-$skilled$($Carpenter$/$Mason$,$ Steelman$/$Mason$),2-$unskilled.

Required: Estimate the quantities and duration of work

$\backslash$table$[[,$Activities,Labor Rates,Qty$,$Days$],[$A$.,$Excavation,$1\mathrm{.}00\frac{m^3}{M}D,,],[$B$.,$Gravel Bedding,$1\mathrm{.}36\frac{m^3}{M}D,,],[$C$.,$Rebar placement,$95\mathrm{.}74k\frac{g}{M}D,,],[$D$.,$Concrete Mixing $($manual$),0\mathrm{.}41\frac{m^3}{M}D,,],[$E$.,$Concrete placement,$1\mathrm{.}89\frac{m^3}{M}D,,],[$F$.,$CHB laying,$4\mathrm{.}25\frac{m^2}{M}D,,],[$G$.,$Backfilling,$2\mathrm{.}50\frac{m^3}{M}D,,],[$H$.,$Plastering,$9\mathrm{.}50\frac{m^2}{M}D,,],[$I$.,$Formworks Installation,$0\mathrm{.}61\frac{m^2}{M}D,,],[$J$.,$Formworks stripping,$1\mathrm{.}91\frac{m^2}{M}D,,],[,,,$Total,$]]$