Raising Day Planning Calculator
Crew size, equipment needs, and schedule for a timber frame raising day.
About this calculator
This calculator estimates crew size, crane needs, and schedule for raising a timber frame from industry rules of thumb. Crane Required flips on at exactly 400 lbs: any Heaviest Timber Weight of 400 lbs or less assumes hand raising (with a gin pole), and 401 lbs or heavier triggers a crane along with a bump in Recommended Crew Size, since a crane also needs riggers and a signal person. Recommended Crew Size itself is driven by that same heaviest single timber -- roughly one person per 100 lbs, minimum 4 -- and is completely independent of how many pieces are being raised in total, so Connecting Girts and Roof Purlins never move it.
Raising Rate (bents/hour) slows down for larger bents (postsPerBent above 3) and for heavier average timbers (above 200 lbs), which then drives Raising Days Needed alongside the time spent on Connecting Girts and Roof Purlins (about 15 minutes each) and setup/breakdown. Total Timber Pieces adds up every bent's posts, tie beams, and knee braces across all bents, plus the connecting girts and purlins entered separately -- so both Number of Bents and Connecting Girts move that total directly, while neither affects crew size or crane requirements at all. Safety Equipment Items scales with crew size (3 items per person) plus fixed first-aid and tag-line counts.
Inputs
Results
Recommended crew size
6 people
Raising days needed
2 days
How to Use This Calculator
- Enter Number of bents, Posts per bent, and Average timber weight.
- Set Heaviest timber weight, Connecting girts, and Roof purlins.
- Review Recommended crew size (people) and Raising days needed.
- Use Total raising hours (hrs) and Crane required to inform your decision.
What each input means
- Number of bents
- Total number of bents (cross-frames) to raise.
- Posts per bent
- Number of posts in each bent (2 for simple, 3+ for interior posts).
- Average timber weight
- Average weight of individual timber members.
- Heaviest timber weight
- Weight of the heaviest single timber. Over 400 lbs typically requires a crane.
- Connecting girts
- Number of horizontal girts connecting bents together.
- Roof purlins
- Number of roof purlins to install.
What each result means
- Recommended crew size
- Minimum recommended crew for safe, efficient raising.
- Raising days needed
- Estimated working days for complete raising (8 productive hrs/day).
- Total raising hours
- Total clock hours for the raising process.
- Crane required
- 1 = crane needed (heaviest timber > 400 lbs), 0 = hand raising possible.
- Minimum crane capacity
- Required crane lifting capacity with 2× safety factor.
- Total timber pieces
- All timbers including bents, girts, and purlins.
- Pieces per bent
- Posts + beams + knee braces in each bent.
- Raising rate
- Estimated bents raised per hour based on complexity and weight.
- Total person-hours
- Crew size × raising hours for labor planning.
- Safety equipment items
- Number of personal and site safety items to stage.
- Bent timber pieces
- Total pieces that are part of the bents (excluding girts/purlins).
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersNumber of bents = 5, Posts per bent = 3, Average timber weight = 200, Heaviest timber weight = 500 = 6 input(s) provided
- Calculate Recommended crew size6 = 6
- Calculate Raising days neededRaising days needed = ceil(totalRaisingHours / productiveHoursPerDay)2 = 2
- Calculate Total raising hoursTotal raising hours = bentHours + connectingHours + setupHours12 = 12
- Calculate Crane requiredCrane required1 = 1
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Does adding more connecting girts or purlins change the recommended crew size?
No. Recommended Crew Size is driven entirely by Heaviest Timber Weight (roughly one person per 100 lbs, minimum 4, with an added bump once a crane is required) -- Connecting Girts and Roof Purlins add time to Total Raising Hours and pieces to Total Timber Pieces, but they never change how many people the calculator recommends staging for the day.
Why does Crane Required flip on at exactly 400 lbs?
The calculator treats 400 lbs as the practical ceiling for hand-raising a timber with a gin pole, consistent with common timber-framing crew practice -- any single piece at 401 lbs or heavier trips Crane Required to 1, which also raises Recommended Crew Size (a crane crew still needs riggers and a signal person even though fewer people are physically lifting) and adds setup/breakdown time for the crane itself.
What happens to the recommended crew as Heaviest Timber Weight keeps increasing?
Recommended Crew Size never decreases as Heaviest Timber Weight rises across its full 50-10,000 lb range -- it climbs roughly with weight below the 400 lb crane threshold, jumps up at the threshold itself, and continues climbing (though at a shallower rate, 70% of the hand-raising formula) once a crane is in the picture, since the crane absorbs some of the lifting but riggers and signal crew still scale with the load.
Do the number of bents and the girt/purlin count affect the same things?
Both raise Total Timber Pieces, but differently: Number of Bents multiplies through Pieces Per Bent (posts + tie beams + knee braces for every bent), while Connecting Girts and Roof Purlins are added on top as flat counts. Both also add to Total Raising Hours, but only bent count feeds the bents/hour raising-rate calculation -- girts and purlins are estimated at a flat 15 minutes each regardless of bent complexity.
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Timber Frame Design Calculator
Beam sizing from span, load, and wood species using NDS bending and deflection checks.
Timber FramingTimber Volume Calculator
Board feet, cubic volume, and weight from timber dimensions and species.
Timber FramingSIP Panel Calculator
Structural insulated panel count, R-value, and cost from wall/roof dimensions and panel thickness.
Life Stage BudgetsCost of Raising Child
Sum of rising annual costs with inflation (illustrative USDA-style midpoint).
More in Construction & Building Trades.