This tool tackles the “Energy Vampire” of tiny homes: the wheel well. It’s a thin piece of sheet metal separating your living space from freezing road spray. This calculator helps you design an insulated box that stops the cold without stealing too much precious floor width.
It features a “Thermal Layer Visualizer” that shows exactly how adding inches of Rigid Foam or Spray Foam pushes the “Freeze Line” away from your interior.
Wheel Well Box Designer
Build insulated boxes that stop cold spots.
1. Fender Dimensions
How far it sticks out from the wall.
2. Insulation Strategy
- 0 sq ft Insulation
- 0 sq ft 1/2″ Plywood
- 1 Tube Constr. Adhesive (PL Premium)
- 1 Can Spray Foam (Gaps)
The “Cold Bridge” Killer
Simply gluing rigid foam to the metal isn’t enough. You must seal the seams where the foam meets the subfloor with Spray Foam (Great Stuff) or acoustic sealant. Even a pinhole leak here acts like a blowtorch of cold air into your home.
Layer 1: Steel Fender
Layer 2: Adhesive (PL Premium)
Layer 3: Rigid Foam (R-10)
Layer 4: 1/2″ Plywood (Protection)
This creates a durable, walkable box that won’t dent when you step on it.