Shed & Outbuilding Repair on San Juan Island

Almost every property on this island has one: a shed, a garden building, an old pump house, a chicken coop, a woodshed, a barn that has become storage. They get no maintenance because they are not the house, and then one day the door will not shut, the floor gives underfoot, and the mice have moved into the lawn tractor. The good news is that outbuildings are simple structures, which makes them cheap to fix if you get to them before the sill goes.

The sill is the thing to worry about. Most island sheds sit directly on skids, blocks, or a slab, often with the wood in contact with soil or with a gravel path built up against it over the years, and once the bottom plate stays wet through eight months of wet season it rots quietly from underneath. You find out because the wall above it starts to move or the door racks out of square. Cutting out and replacing a rotted sill, raising the building enough to get pressure-treated material under it, and correcting the drainage or grade that caused it is bread-and-butter work and it saves the rest of the building.

Doors are the most common call. A shed door drags because the building has racked, the hinges have pulled out of soft wood, or a Z-brace was never installed and the door has sagged on its own diagonal. The fix depends on which, and it is worth diagnosing rather than planing the bottom of the door, which is what most people do and which just moves the problem. On sliding barn doors it is nearly always the track, the hangers, or the header the track is screwed to.

Rodents are the other constant here. Field mice, rats, and the deer mice that come out of the woodpile will get into any outbuilding through a gap you would not credit, and the routes are always the same: the gap under a badly hung door, the corner where siding meets an out-of-square sill, unscreened gable and soffit vents, and any hole a previous owner cut for a hose or a cord. Exclusion is a carpentry job, not a poison job. Rodent-resistant metal mesh at the vents, hardware cloth over the openings that need to breathe, blocking and flashing at the sill line, and a door that closes tight. If you have an active infestation, that is pest control’s job and it should happen first; I seal the building so it does not come back.

Ventilation is the counterintuitive one. A shed sealed up tight against weather with no airflow becomes a condensation box — you get water dripping off the underside of the roof sheathing on a cold clear night and tools rusting on the bench in a building that has never leaked. Island humidity makes this common. The fix is screened intake low and exhaust high, and it costs almost nothing when the building is already open for other repairs.

The rest is straightforward carpentry: replacing floor sheathing and joists where the floor is spongy, patching or replacing siding, rebuilding a rotten corner, resetting a shed that has settled off level, replacing fascia and trim, adding a proper workbench or shelving, hanging a new door. Woodsheds get their own attention because they need air on the wood, which most enclosed ones do not have. Pump houses I will repair the structure of, and only the structure.

Clear boundaries, because outbuildings are where people ask for everything. I hold a Washington general contractor registration, not an electrical or plumbing license. I do not run power to a shed, add a receptacle, wire a light, or touch anything to do with the pump, the pressure tank, or the supply lines in a pump house — that work requires the specific license and it goes to a licensed electrical or plumbing contractor. I will line one up and meet them at the property. I also do not do roofing or re-roofing, structural or load-bearing alteration, or new outbuilding construction requiring engineering. Roof moss on an outbuilding is covered under gutter cleaning and moss removal.

Whether it is worth repairing is a fair question and I will answer it straight. A shed with a sound frame, a bad sill, and a racked door is a good repair. A shed where the studs are punky top to bottom and the roof structure is failing is not, and I will say so rather than take a day’s money to prop it up for one more winter.