Mukilteo drops toward the ferry and the Sound. Salt reaches the lower streets, and the hills above the terminal shed water down through yards that were cut into the slope. A flat inland detail does not survive on these lots. A rock wall on sand needs a base that does not wash out. Pretty stone on a bluff edge, with the tide of runoff under it, is a temporary arrangement.
Snohomish County · ZIP 98275 · 2020 population 21,246
Rock that can take wind and a sandy toe
We dig the toe in, we drain the back, and we do not outlet that drain as a spout over the bank. The stone can look natural against madrone and shore pine. We avoid a formal, mortared look that cracks when the bank moves a half inch, which marine slopes do.
Salt does not bother the rock. It bothers the metal pins and the cheap edging people ask us to add. We keep the wall stone.
The ground in Mukilteo
Hillside runoff is the job. A patio with a view is also a patio that can send water at the house if the base and the pitch are wrong. We build the drain before the pavers, and we hold the bank with a wall that has rock or drain tile behind it, not a decorative stack sitting on the sod.
Salt-tolerant natives belong on the exposed edges. Pressure washing is how you get the marine film off a walk and a railing; it comes back, so we treat it as upkeep. Lawns on the upper, slightly flatter streets behave more like the rest of the county — clay, moss, shade from big trees — and we maintain them that way. The waterfront lots are a different trade: erosion, wind, and a view you do not want to block with a hedge.
How we do the work
A rock wall is dry-stacked or lightly set, with the weight in the stone and the drainage in the voids. It is not a veneer glued to a failing timber wall. We use rock big enough for the height, with a face that leans back into the hill, and smaller rock locked behind so the soil does not pipe through.
Good rock work looks heavier at the bottom. If every stone is the same patio-sized block, it is not a wall, it is a stack. We source local stone and we will tell you when the access cannot take the boulder the job wants.
What we look at first
- Height and whether it is structural or a garden edge
- Machine access for real boulders
- The soil behind: clay that needs a drain, or rock that already sheds
- An existing wall we are tying into
Tying into old rockery
We can often continue an existing rockery if the old base is still honest. If the old wall is tipping, we take it down and use the good stone again. Matching a lean is how you extend a failure.
The base course
The biggest stones, buried, on compacted rock or competent ground. If the first course is the one you can see sitting on the grass, the wall is already failing. You should see the second course at grade, not the bottom of the first.
Dry stack versus mortared
Most of our rock walls are dry, so water can leave and the wall can move a little without cracking a joint. Mortar is for a low, formal edge that is not holding a wet hill. We do not mortar a drainage problem shut.
More from this crew
- Rock walls across Snohomish County
- Retaining walls in Mukilteo
- Gravel installation in Mukilteo
- Landscaping in Mukilteo
- Hardscaping in Mukilteo
- Rock walls in Everett
- Rock walls in Edmonds
- Rock walls in Mill Creek
Sources for the climate and the water
- USDA plant hardiness map for choosing plants that can take a Snohomish 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.
