This tool demystifies one of the trickiest parts of tiny house framing: the wheel wells. Since the trailer wheels cut into your floor plan, you have to cut your wall studs short. This creates a structural gap exactly like a window or door.
The calculator helps builders size the “Header” (the beam bridging that gap) correctly to prevent the roof from sagging over the tires.
Wheel Well Header Guide
Bridge the gap: Frame over axles without sagging.
1. The Gap (Span)
Lumber placed on edge.
*Visual simplified. Typically, the header sits just above the fender box.
It’s Just Like a Door
Structurally, a wheel well is identical to a window or door opening. You are removing studs that carry roof load. Therefore, you must install a Header to transfer that weight horizontally to the “Jack Studs” on either side of the wheels.
Don’t just rest the header on the fender box! The fender is usually thin sheet metal. The weight must be carried by wood framing all the way down to the trailer frame. Use Simpson Straps to tie the header to the jack studs to prevent uplift.