Shed Floor, Door and Sill Rot: What Can Be Repaired
By Jeff Rabkin, JustFix Wood · Published October 14, 2026
A shed with a soft floor or a door that won't close usually looks worse than it is. If the roof is keeping water out, most sheds are worth saving.
Why sheds rot from the bottom
Sheds often sit close to the ground, on blocks or skids. Snow piles against the walls, and leaves and soil build up around the base. The bottom of the shed stays damp, and that's where rot starts: the floor edges, the skids, the sill plate under the walls and the bottom of the siding and trim.
Soft floors
A spongy floor is usually rotted plywood or OSB decking, and sometimes the joists under it. I pull the bad decking, check the joists, sister or replace the soft ones and lay new exterior-rated sheathing. If only one area is bad, often near the door, I can patch just that section.
Rotted sill plates
The sill plate is the bottom board the walls sit on. When it rots, the walls can settle and the door frame goes out of square. I support the wall, cut out the rotted section and put in new pressure-treated lumber. It's careful work, but it's a lot cheaper than a new shed.
Sagging or sticking doors
Shed doors sag for the same reasons gates do: loose hinges, no diagonal brace, or a frame that has shifted. Sometimes the door is fine and the problem is a settling sill. I fix the cause, then re-hang and re-latch the door.
Siding and trim
Rotted trim and the bottom courses of siding can be replaced piece by piece. I also fix the cause, like adding clearance at the bottom or flashing at the base, so it doesn't come right back.
Worth repairing or not?
- Good roof, bad floor or sills: repair
- Sagging door: almost always repair
- Roof leaking and walls rotting: it may be time to replace the shed
Send photos of the whole shed, the floor near the door and the bottom of the walls. Text them to 612-382-1306.
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