Plan your outdoor project
Greenhouse & Plant Protection Guide
Choose greenhouse covering for the season and plants you intend to protect, then measure the structure. Thickness matters, but it cannot tell you whether a film admits the light you need, has the right UV specification or comes in a width that reaches both sides of your frame.
Decide what the covering must do
Clear growing film and white overwintering film are not interchangeable descriptions. Farm Plastic Supply’s greenhouse-film range includes different grades for different uses, while its white greenhouse covering reduces incoming light. Use the particular film’s light-transmission and intended-use specifications to decide whether that suits your crops and season. Do not transfer a percentage from one thickness or grade to another.
| Question | Why it changes the choice |
|---|---|
| Is this a growing cover or an overwintering cover? | You need the light and protection characteristics of the selected grade, not simply its color. |
| Is UV exposure specified for this exact film? | Construction sheeting and greenhouse film can look alike. A thickness figure alone does not establish outdoor service life. |
| Does the roll reach across the frame and its attachment points? | Floor width leaves out the curved roof, side walls and material needed at the edges. |
| Does the fixing system accept this material? | Film thickness, reinforcement and the frame’s attachment method must be considered together. |
Read thickness as a measurement, not a promise
A mil is one-thousandth of an inch: 10 mil means 0.010 inch. It does not mean ten millimeters, and it does not by itself guarantee a particular number of seasons. Compare the manufacturer’s stated grade, reinforcement and UV treatment alongside thickness. If a seller quotes a service life, check which product it applies to and what conditions or warranty terms qualify it.
Our 10-mil reinforced clear film listing specifies a 24-by-40-foot sheet. That makes it a concrete option to compare when you need a reinforced covering in that size. It is not evidence that the roll will fit a frame with a 24-foot floor width, nor a basis for transferring the warranty of a different film. Confirm the selected roll and fixing method before ordering.
Measure the route the film must follow
For an arched structure, measure along the frame from the intended fixing point on one side, over the arch, to the fixing point on the other. Record the length in the same way and add the material required by the fixing system’s instructions. Treat end walls, doors and vents as separate pieces where the design requires them. A sketch of each piece is easier to check against a roll than one combined square-foot total.
Orientation also matters: a roll can contain enough total area and still be too narrow for the main span. Check both dimensions before planning cuts. Leave required openings and ventilation in the design; covering material does not replace the greenhouse manufacturer’s ventilation or structural requirements.
If the project is temporary frost protection for individual plants, first decide whether you need a greenhouse skin at all. The right product should explicitly suit the intended plant-protection use. Browse greenhouse covering plastic once you know the purpose, grade and individual cut sizes, rather than choosing by thickness alone.
Reviewed October 1, 2026 by Eco Sweet Home. Based on manufacturer specifications and the sources linked above; no hands-on product testing is claimed. Confirm the selected model, pack quantity and included parts on the product page. For an unresolved specification, contact us before ordering.
