Why the irrigated side of an Idaho house gets hit first
Walk any yard in the Treasure Valley in July and you can find the wet edge without a moisture meter. It is the strip of turf that stays green against the stem wall, the bed under the drip emitters, and the ground below the swamp cooler line. In a state averaging about 12 inches of precipitation, that strip is the only dependable moisture in the top foot of soil for months. Subterranean termites forage where the soil stays workable. Dry, compacted ground slows them; irrigated ground does not. So instead of pressure spread evenly around a house, Idaho homes tend to show a hot side and three quiet ones. That is useful information. When you inspect, start on the irrigated side and the shaded north wall. Check where the sprinkler throw hits siding, where a downspout dumps against the foundation, and where a planter box sits flush against the wall. If tubes exist, that is where they usually are, and a technician who does not look there first is not looking hard.
A month by month look at termite season in Idaho
Late winter is quiet above ground. Colonies feed below the frost line while surface soil is frozen, so you will not see new tubes, but existing damage is still expanding at depth. April and May are the months to pay attention. As soil warms and the first real irrigation cycles start, foraging returns to the top of the soil and mature colonies release winged swarmers on warm, still afternoons following moisture. Higher elevation areas around Idaho Falls run later than the lower Snake River Plain. June through August is the working season. Sprinklers run daily, the soil against the foundation stays damp, and tube building is at its peak. This is the best window for a homeowner walkaround because tubes are fresh and easy to spot. September and October are the practical time to schedule treatment, since soil is still workable for trenching and you get the barrier in place before the ground hardens. November through February, expect inspections rather than digging.
What a real termite inspection covers
A good inspection is mostly a crawl and a poke, not a sales pitch. Expect the inspector to walk the full exterior perimeter looking at the joint where siding meets grade, then get into the crawlspace with a light and a probe. In the crawlspace they are checking piers, the sill plate, the rim joist and the underside of the subfloor, especially under bathrooms and the water heater. They will sound wood with a screwdriver handle, break open anything that gives, and look for shelter tubes running up the inside of foundation walls where no one ever sees them. Inside, they look at baseboards on exterior walls, window sills for shed wings, and any spot where a slab meets framing. On slab homes they pay attention to plumbing penetrations, expansion joints and the garage-to-house wall. Ask for the findings in writing with a diagram of where activity was found, and ask specifically what they could not access. The unreachable areas are where surprises live.
Slabs, crawlspaces, and why the construction type changes the plan
Idaho's newer subdivisions lean heavily on slab-on-grade and shallow crawlspace construction, and the two need different treatments. On a slab, termites travel through settlement cracks, expansion joints and the gap around plumbing penetrations. Nothing about that route is visible until damage reaches drywall or trim. Treating a slab home means drilling through the concrete at intervals along interior bearing walls and around penetrations, then patching, in addition to trenching the outside perimeter. That drilling is a real part of the labor and shows up in the quote. A crawlspace home is easier to inspect and easier to treat, because you can see the piers and sill plate directly. Its weakness is moisture: an unvented or poorly drained crawlspace holds humidity that termites and rot both like, particularly under a house with irrigation on three sides. When you compare bids, make sure both companies are pricing the same construction. A slab quote with no drilling line item is worth a question.
Renters, landlords, and who pays for termite work
Structural pest treatment is almost always the property owner's expense, not the tenant's. termites attack the building itself, and the sill plates and joists they eat belong to the landlord no matter who lives there. What a tenant owes is prompt notice. If you rent, report mud tubes, wings on a sill, or a soft floor in writing the day you see it, and keep a copy. Photos with dates matter later if there is an argument about how long the condition existed. Landlords should treat a termite report as a building maintenance item on the same footing as a roof leak. The cheap version is an annual perimeter check. The expensive version is discovering a rotted and hollowed rim joist during a turnover. For multi-unit buildings, remember that a soil colony does not respect unit lines. Treating one apartment's baseboard while leaving the shared foundation untreated just moves the problem to the neighbor.