The label area is not the coverage
Every roll of anything laid in strips loses width to the overlap, and the loss is proportionally worse the narrower the roll. A 3 foot by 200 foot roll of floor film is 600 square feet on the label. Lap it 2 inches and the usable width is 2.83 ft, so a roll actually covers 567 square feet, which is 94 percent. That is the small case. A 2 foot roll lapped 3 inches loses an eighth of itself.
The same arithmetic runs on sheeting for openings, except there the loss is not overlap but the extra you need on all four sides. A 3 by 7 foot doorway taped 12 inches onto the wall all round is a 5 by 9 foot piece, which is 45 square feet rather than 21. More than half of the material is the part you tape to.
Where the tape goes, and why it is more than you think
| Run | Default job |
|---|---|
| Round three openings, all four edges of each 5 x 9 ft piece | 84 ft |
| Floor seams, one per 2.83 ft of width | 120 ft |
| Floor edges, rough perimeter | 74 ft |
| Plus 10 percent | 306 ft |
Three hundred feet of tape on a 340 square foot job, which is two 180 foot rolls. The perimeter figure for the floor is a stand-in rather than a measurement: it treats the area as a square, which understates a long corridor and overstates a compact room. If the protected area is a hallway, expect more, and the seam figure grows with it because a narrow room is mostly seam.
Film, paper or board
They do different jobs and the choice is not about cost. Self-adhesive film stays put on a finished floor and resists a boot; it does not resist a wheelbarrow or a dropped cast iron fitting. Rosin paper is cheap, breathes, and is what goes under something else rather than being the something else. Hardboard or panel over paper is what you use where material is being carried out, because the wheel and the corner both land on the board and the paper keeps grit off the finish underneath.
Board is also the only one that is a real cost. Thirty-two square feet a sheet means a 340 square foot floor is twelve sheets, which is a delivery rather than a purchase, and they have to go somewhere afterwards. That is worth deciding before demolition day rather than during it.
What protection cannot do
It keeps grit, mud and dropped tools off surfaces that are staying, and it makes the clean-up at the end an hour rather than a day. It does not make a demolition clean. Fine dust goes everywhere regardless, through gaps, up stairs, into ductwork and into rooms nobody opened. And it has nothing at all to say about hazardous material: if what is being disturbed might contain asbestos or lead, that is not a plastic and tape question and never was. Test first and route it to people licensed to deal with it.
For the demolition that produces the dust, the remodel debris calculator covers the tear-out quantities, and the dumpster fit calculator deals with where the material goes and how far it has to be carried across the floor you just covered. If the walls are going back up afterwards, the drywall sheet calculator covers sheets, screws and compound.
Questions people ask
How much floor protection do I need?
Take the area you are covering, add waste, and divide by the usable coverage of the roll rather than the printed one. A 3 by 200 foot roll lapped 2 inches covers 567 square feet, not 600, so a 340 square foot floor with 10 percent waste needs 374 square feet of coverage and one roll does it. The overlap is why people who divide by the label figure end up short.
How much plastic do I need to cover a doorway?
More than the doorway. A 3 by 7 foot opening taped 12 inches onto the surrounding wall all round is a 5 by 9 foot piece, so 45 square feet instead of 21. Three of those is 135 square feet, and a 10 by 100 foot roll covers it many times over, which is why sheeting is rarely the thing you run out of.
Is rosin paper or plastic film better on a floor?
They are for different situations. Film sticks down and stays put underfoot, which is what you want on a finished floor in a room that is only being walked through. Paper is cheap and breathes but slides and tears. Neither survives a wheelbarrow, which is why anything on a debris route wants hardboard or panel over paper, with the board taking the wheel and the paper keeping grit off the finish.
Does covering the doorways keep the dust out of the rest of the house?
It reduces what walks through and it does not make the rest of the house clean. Fine dust travels through gaps, up stairwells and into any ductwork that is open, and it will be found in rooms nobody entered. Treat protection as reducing the clean-up rather than preventing it, and be honest with yourself about which of those you are buying.
What about asbestos or lead — is sheeting enough?
No, and it is the wrong question. If the building is old enough that asbestos or lead paint might be in what you are about to disturb, the sequence is testing first by a certified inspector, then licensed abatement if a sample is positive, and whatever your state environmental agency requires on top of that. There is no materials take-off that answers it and this page has nothing useful to add.