First Line Sales
PO Box 200
Vernon, VT 05354
www.firstlinesales.com
Construction Estimating
Formulas & Useful Information
Formulas, equations, tables, facts, specifications and
other
information useful in planning and estimating construction,
decorating and other projects.
Measure of Dimensions, Theorem
▪
Formulas, Rectangles, Squares, Triangles
& Circles ▪
Board Feet
Concrete Estimating
▪ Decimal and Metric Equivalents
▪ Weights, etc.
▪ Metrics
▪ Energy, Electric, Insulation
▪
Drywall Estimating, Door Handing
Cord Wood:
A cord of wood measures 4' x 4' x 8'.
Stacked cord contains 128 cubic feet by measure. Actually is 80 cubic feet
the rest is air.
Weighs 3,000 pounds when dry, 4,000 pounds when wet.
Seasoned wood is defined as having 25% moisture content. Four percent of
its energy is lost in the evaporation process as it burns.
Green wood is defined as having 80% moisture content. Fifteen percent of
its energy is lost in the evaporation process.
Fuel energy BTU comparison:
Heating Oil 
138,000 BTU per gallon (number 2 fuel oil) 
Natural Gas 
100,000 BTU per therm 
L P gas 
93,000 BTU per gallon 
Mixed Hardwood 
8,600 BTU per pound based on seasoned wood weighing +/ 3,000
pd. per cord. 24,000,000 BTU per cord (+/) 
Electrical formulas: 1. Amps = Watts / Volts
2. Watts = Amps x Volts
3. Volts = Watts / Amps
Insulation: The Rvalue of materials measures its resistance to heat
flow. The higher the R value, the better the resistance to heat flow.
The Uvalue is used to calculate heat loss.
Formula to find Uvalue is: 1 / R  value = U  value.
Rvalues of some common building materials:
1" Fiberglass batt,
Insulation 
3.17 

1" Expanded
polystyrene 
4.00 

1" Extruded
polystyrene 
5.0 
1" Polyisocyanurate,
foilfaced 
7.20 

8" concrete block 
1.11 

1' Poured concrete 
0.08 
1" Soft wood lumber 
1.25 

2x4 kds 
4.38 

2x6 kds 
6.88 
1/2" plywood 
0.63 

3/4" plywood 
0.94 

1/2" gypsum board 
0.45 
Window with
single glass 
0.91 

Windows with
IG glass 1/4" air sp. 
1.69 

Windows with 1/2"
Low E IG 
3.13 
Wood solid core
13/4 door 
3.03 

Metal ins. door
no glass 
15.00 

1/2"  4" air space 
1.00 
Temperature Formula: Degrees Fahrenheit  32 x 0.56 = degrees Celsius
Degrees Celsius x 1.8 + 32 = Degrees
Fahrenheit
Liquid:
1 ounce = 29.57 milliliters
1 quart = 0.95 liter
1 gallon = 3.79 liters
Measure of Dimensions, Theorem
Formulas, Rectangles, Squares, Triangles
& Circles
Board Feet
Concrete Estimating
Decimal and Metric Equivalents
Weights, etc.
Metrics
Energy, Electric, Insulation
Drywall Estimating, Door Handing
This information is believed to be
accurate. The Polymer Roof Factory or First Line Sales will not be
liable for errors and omissions. Specifications, detail, and other
information should be verified by the user.
