Short answer
Late summer and fall are peak web season around the Treasure Valley, and spiders favor eaves, soffits, window corners, and anywhere porch lights attract insects. A soft-wash house washing clears webs and egg sacs from the whole exterior; window cleaning clears them from glass, frames, and screens. Washing isn't pest control, but it makes a big visible difference.
Why webs pile up
Outdoor lights draw insects at night, and spiders build where the food is. Covered, sheltered spots — under eaves, around window frames, in porch corners — protect webs from wind and rain, so they accumulate quickly through the warm months.
What washing does (and doesn't) do
A house wash removes webs, egg sacs, and the dust and insect debris stuck to them from siding, eaves, and soffits. It doesn't treat pests — if you have a real infestation, a pest control company is the right call. Many homeowners do both: a pest treatment and then a wash to clear away what's left.
Small things that help
Switch porch lights to warm or yellow 'bug' bulbs
Keep shrubs trimmed back from siding and windows
Brush down webs regularly in high-traffic areas
Rather have a pro handle it?
Pro Solutions does house washing across Boise and the Treasure Valley. Quotes are free, itemized, and usually texted the same day.