The shed designer's gambrel barn can have a storage loft on its truss ties, over half the shed's length or all of it. Until now the loft had a floor and no way to reach it. The lane that built the barn listed that as open.
A half loft is open over the other half of the shed, so the tool frames a ladder leaning on the loft's edge joist:
- two 2x4 rails 16" apart in the clear, leaning 1 in 4;
- a level cut at the foot, a plumb cut at the top, screwed to the joist;
- 2x4 rungs 12" apart, inside the 10" to 14" OSHA 1910.23 spaces ladder rungs.
The rails and rungs are in the cut list, the 3D view and the build steps like any other board. They add about $12 on the 10x10 barn preset.
A full loft covers the whole length, so it needs a hole:
- The hatch. The floor is left out over the bay nearest the left gable that is at least 22" clear between joists, 30" across the width. That is the least attic opening IRC R807.1 asks for. With trusses at 24" the bay is 22-1/2" clear, which passes.
- Narrower bays. With trusses at 16" the bay is only 14-1/2". The tool still cuts the hatch there, and it says that this is under R807.1's 22" and that a wider, headered opening or trusses at 24" would fix it.
- The floor around it. The floor pieces it overlaps are cut round the hatch, and the ladder stands under it.
Two practical checks.
- The door. On the 10x10 barn preset the door is in the left gable end. A ladder down the middle would have landed in the doorway, so when a gable door is near the middle the ladder and hatch move toward the back wall.
- Short sheds. In a shed too short for a 1 in 4 lean to land inside the walls, the tool leaves the ladder out and says to use a stepladder. The random-design sweep found that case: a 4 ft long barn whose ladder foot ended up in a wall stud.
The loft is still sized for 20 psf of stored things (IRC Table R301.5), not for people to stand in. The ladder reaches the loft floor with no handhold above it, and the notes say so. Not engineered or code-checked.