Sammamish sits on a plateau above Lake Sammamish, and most of it was built out as subdivisions in the last thirty years. Under a thin layer of topsoil is glacial till, a hardpan that water barely soaks into, and many lots back onto tall stands of Douglas fir. Shade and drip feed the growth. We can clean the patio and the siding. We cannot make a cedar canopy into a sunny courtyard.
King County · ZIP 98074
Film on every surface under the trees
Decks and fences in the shade get a low-pressure wash and a treatment. Blasting the soft grain out of a deck board makes it hold more moisture next year. We would rather do it twice gently than once violently.
Needles and debris get blown off first. Washing a mat of debris just makes mud and drives it into the joints of the pavers.
The ground in Sammamish
The till is the reason so many yards here stay soggy in winter and dry out fast in summer. Water sits on top of the hardpan, so a new lawn or patio needs drainage planned in from the start. We put in French drains, grade the yard away from the house, and build patio bases deep enough that they do not heave.
Many neighborhoods have HOA rules for fences, front yards, and plant choices, and we work to those standards. Lots along the greenbelts get heavy shade and needle drop, so we use shade-tolerant planting and bark where grass has given up. Larger backyards here are a good fit for a full redesign: a paver patio, a low retaining wall to level the slope, and irrigation on a timer for the dry months.
How we do the work
Most of what people call pressure washing here is organic film: the black and green on the north side, the walks, the fence. The fix is the right tip, the right distance, and often a wash that kills the growth so it does not return in a month. A zero-degree tip on a soft wood deck is how you get a furred, ruined deck.
We do not drive water up under lap siding or into a vent to prove the washer is strong. High pressure is for concrete that can take it. Wood, paint, and mortar joints get a softer approach.
What we look at first
- What the surface is
- Where the water will run
- Plants and outlets we need to protect
- Whether the black is mildew that needs a treatment, not just a blast
Wood versus concrete
Concrete can take a stronger wash. Cedar decks, fences, and soft siding cannot. If we raise the grain, the surface holds more dirt afterward. We would rather leave it a shade less bright than furred.
How often
North sides and shaded patios, about once a year if you care. Sunny south walks can go longer. Exposed marine rails may want it yearly. We do not sign you up for a monthly wash of a surface that does not need it.
Treatment
A wash that kills the algae and mildew, applied and rinsed, is why the surface stays clean longer than a blast. We use it where the film is biological. We do not soak your vegetable bed in it. Plants get rinsed.
More from this crew
- Pressure washing across the region
- Patio installation in Sammamish
- Paver installation in Sammamish
- Fence installation in Sammamish
- Yard cleanup in Sammamish
- Pressure washing in Mercer Island
Sources for the climate and the water
- USDA plant hardiness map for choosing plants that can take a King County winter.
- EPA WaterSense on watering less once a lawn or a new planting is established.
- EPA Soak Up the Rain on keeping roof and yard water from becoming someone else’s problem.
