Where do you start when
figuring the lumber you need to build a house? For a lot of
people doing a lumber takeoff from a blueprint could be a
daunting task. By taking logical steps anyone with basic
knowledge of how a house is built can make a lumber
The easiest way to figure
lumber amounts to build a house is to start at the beginning.
By this I mean figure the lumber in the order you would build
it. Start with the sill plates and finish with the plywood on
As mentioned start your checklist
with the sill plates. Figure the lineal footage and divide by
the lengths of lumber you want to use (10', 12', 14',
Next on the list would be the 1st
floor framing and sheathing. This would first include the floor
joists. These are usually 2x10's or 2x12's. Use the lineal
footage for sill plates to get the amount of rim joists. Figure
the lengths that are needed and how many of each that are
needed for 12" or 16" on center. Include bridging for the floor
joists whether it be solid or cross bridging. The last item for
the 1st floor deck is the 3/4" tongue and groove plywood or
OSB. This can be done by figuring the square footage and
dividing by 32 to get the amount of sheets of plywood
After the floor comes the walls.
This can be broken down to exterior walls and interior walls.
Again the lineal footage for the sill plates can be used to
figure the exterior wall plates and studs. Take this figure
times 3 to get the amount of material for bottom plates and the
double top plates. For exterior wall studs figure one stud for
every lineal foot. This takes into account window and door
openings, wall intersections and corners. To get the wall
sheathing amount, take the sill plate lineal footage and divide
by four. For interior walls, figure the lineal footage and
figure one stud per foot. For headers, add the opening widths,
multiply times two and divide by the length of material to get
amount of pieces.
Next is ceiling joists. These
usually have to be figured room by room and are usually 16" on
center. Also size of ceiling joists can vary from room to room
depending on the span.
Lastly,the roof system is
figured. For a basic gable roof with rafters 16" on center,
figure 3 rafters for every four feet plus one. Don't forget the
ridge board which will run the entire length of the building.
Also include material for a gable overhang if there is one. If
it wasn't already built into the end exterior walls, include
studs and sheeting material for the gable end walls.
If the roof is a hip roof it will
have the same amount of rafters as a gable. The difference will
be including four hip rafters and less ridge board.
When figuring the plywood
sheeting for a gable roof, multiply the length times the width
of one side of the gable. Take this number times two (both
sides of the gable) Take this number and divide it by 32
(square feet in a 4 x 8 sheet of plywood). This will give you
the total number of sheets of plywood to cover the
For a hip roof, even though it is
shaped differently, it will take the same amount of plywood to
cover its rafters.
To finish off the roof system,
add collar ties, fascia boards and soffit material to your
In closing, figure it like you
would build it and you can't go wrong. After you have done it a
couple times it will become very easy.
More lumber takeoff
Lumber Amounts for Homebuilding