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Count twice: roof plan counts vs the trade sheets
Why count roof items twice on a takeoff?
Drains, penetrations and curbs appear on the roof plan and on the trade sheets, and the counts can differ. Count both, carry the higher count with its source, and put the difference on the Questions tab.
Disclosure: Sharp Pencil sells commercial roofing takeoffs, so we have a stake in this topic.
This is a takeoff checklist, not mechanical, plumbing, code or design advice. The design team and your bid documents decide which sheet governs.
Short answer
Drains, penetrations, curbs and supports show up on the roof plan and again on the plumbing, mechanical and electrical sheets, and the counts can differ. Count each item twice, once on each sheet. Carry the higher count with the sheet it came from, and put the difference on the Questions tab so it can be answered before bid day.
Which items show up on more than one sheet?
Anything another trade draws and the roofer has to flash usually appears twice.
| Item | Roof plan | Trade sheet | Detail page |
|---|---|---|---|
| Roof drains and overflow drains | Roof plan | Plumbing sheets | roof drainage takeoff |
| Scuppers and conductor heads | Roof plan, elevations | Plumbing sheets, elevations | roof drainage takeoff |
| Pipe and vent penetrations | Roof plan | Plumbing and mechanical sheets | penetration and curb takeoff |
| Conduit penetrations | Roof plan | Electrical sheets | penetration and curb takeoff |
| Rooftop unit and fan curbs | Roof plan | Mechanical sheets | penetration and curb takeoff |
| Equipment and pipe supports | Sometimes not shown | Mechanical and structural sheets | penetration and curb takeoff |
The rule: carry the higher count and ask
- Count the item on the roof plan.
- Count it again on the trade sheet.
- Carry the higher count with the sheet it came from, and put the difference on the Questions tab.
The takeoff doesn't decide which sheet is right. The design team does.
What the question looks like
Example data, not a real job. These two lines come from the worked examples on our drainage and penetration pages.
- Drains: the roof plan shows 4 drains and the plumbing sheets show 8.
- Conduit: the roof plan shows 4 conduit penetrations and the electrical sheets show 6.
Each one becomes a line on the Questions tab with both counts and both sheets, and the takeoff carries the higher number until someone answers.
Where to go next
- Drain, scupper and gutter lines: roof drainage takeoff.
- Pipe, curb, skylight and hatch lines: penetration and curb takeoff.
- Which sheets to open: the sheets a roofing takeoff has to read.
- When the plan and a detail disagree: roof plan and details conflict.
- How to write the question: the roofing RFI register.
What you get back from Sharp Pencil
Every quantity carries its source sheet and its basis.
Four files: START HERE, marked-up drawings PDF, Takeoff.xlsx with a Questions tab, and the material order list.
Pricing is optional. Send your cost data and we apply your prices to the quantities. Any line you have not priced comes back marked UNPRICED.
We take off steep slope (standing seam, shingle) and commercial low slope (TPO, EPDM, PVC, mod bit, BUR) from the full set.
FAQ
Why do roof plan and trade sheet counts differ?
Each sheet can come from a different discipline, and a change may not reach every sheet. The takeoff can't tell which one is current, so it lists the difference.
Which count goes in the takeoff?
The higher count, with the sheet it came from. The difference goes on the Questions tab.
What does a takeoff from Sharp Pencil cost?
$395 per takeoff. $395 covers a new set of drawings, or a new address. Your first takeoff is free, one per contractor, on a job you're bidding or quoting.
What does Sharp Pencil send back?
Four files: START HERE, marked-up drawings PDF, Takeoff.xlsx with a Questions tab, and the material order list. Every quantity carries its source sheet and its basis. Usually within one business day. Delivered within 48 hours*.
*Clock starts once any questions we send you are answered.
Why send it to us
- We take off steep slope (standing seam, shingle) and commercial low slope (TPO, EPDM, PVC, mod bit, BUR) from the full set.
- Every quantity carries its source sheet and its basis.
- Four files: START HERE, marked-up drawings PDF, Takeoff.xlsx with a Questions tab, and the material order list.
- Pricing is optional. Send your cost data and we apply your prices to the quantities. Any line you have not priced comes back marked UNPRICED.
- Usually within one business day. Delivered within 48 hours*.
- A plan set you send us will never be used to compete with you, and plan sets are deleted whenever you ask.
- First takeoff free, one per contractor, on a job you're bidding or quoting.
Residential is not our focus today, but ask if you have a job in mind.
*Clock starts once any questions we send you are answered.
Try it on a job you are bidding
Get your first takeoff free · $395 per takeoff · See a sample takeoff
The Sharp Pencil team