What Is R-Value?
In simple terms, R-value indicates how quickly heat is transferred from one material to another. Heat insulators have high R-values. Heat conductors have low R-values.
- The R-value of one inch thick wood is about 1.
- An R-value of about 3.2 can be found in a 1-inch wide strip of fibreglass batting
- The R-value of a 1-inch block of Styrofoam is about 5.
- A thicker material has a higher R-value.
Conduction, convection, and radiation are all methods of transferring heat. Here are 3 myths from which you should be aware!
Myth 1: RV skirts need R-value
Skirting surrounds the base of your RV as an interlocking wall. Travel trailers and fifth wheels often use them during cold weather. Here’s what the myth says:
“The skirting panels must be insulated and have a high R-value.”
The truth is that airflow is more important than R-value. RV skirts prevent cold air from flowing below your trailer floor and sucking away heat. As a result, skirting enables air to do the work on its own! Warm air leaks into the skirting and heats the air.
Myth 2: R-Value is in sales brochures
R-values don’t match what you see! When RV manufacturers say, “Our wall is R-11,” they usually mean either:
- An internal aluminium tube or 2-inch foam core is installed in the walls
- Walls are framed with 2×2 (1-12 x 12 actual) wood stud bays stuffed with 16-inch wide fibreglass batt insulation.
Myth 3: Fibreglass RV insulation is tried & true
Fibreglass batting is still used for insulation in many entry-level “stick ‘n’ tin” RVs. Insulating RVs with fibreglass remains one of the worst choices.
Travelling RVs can cause fibreglass to settle and compress, causing cold spots to form. Glueing the batt facing to the plywood sheathing prevents settling, but foam insulation is a better choice, so choose a RV with foam insulation inside the walls.
