Loftup Spark

Loftup Spark puts a full-size roof on your screen and works out every cutting dimension from the span and pitch you set. No rafter tables to flip through. No manual trigonometry. Drag the span rule, dial in the pitch, and watch rafter lengths, paired bevel angles, and birdsmouth depths update in real time as your finger moves. The Setting-Out Bench draws the roof as a live cross-section that redraws under your touch. Every figure — common rafter length, ridge height, rise, run, seat cut, plumb cut — is derived instantly from a single geometry engine. Eight roof types are covered: lean-to, couple, close-couple, collar, purlin, king-post truss, hipped, and queen-post. Real British structural timber sections from 47x100 mm to 75x225 mm, in grades C16, C24, TR26, Douglas fir, oak, larch, and glulam. The Cutting List generates a full schedule of every timber in the roof — member name, quantity, length in millimetres, plumb angle, and seat angle — ready to save to your photo library and take to the timber yard. The Loft Envelope screen shows usable standing height inside the roof as you vary the pitch and collar height. Point the camera at any existing gable, tap the plate corners and ridge, and the app reads back the span, plate level, and pitch straight from the photo. Built for carpenters, timber framers, and self-builders working on traditional cut roofs. Covers 10 structural members with illustrated cut sequences, 9 named setting-out faults with causes, checks, and fixes, and 12 hand tools of the trade. Fully offline. No account. No subscription.