Concrete Retaining Walls in Mukilteo, WA

Retaining walls in Mukilteo: what to know

Height is taken from the underside of the footing to the top of the wall, which matches the state’s method, so the footing depth is the first figure on the drawing. A surcharge is any load that presses on the wall from behind, whether a driveway, a slope, or a building close by. Each such load is located on the site plan, because a surcharge can change the answer for a wall that stands low.

Chapter 15.04 adopts the building code, and its text was not readable in our research. The state exemption is therefore confirmed against that adoption before design. On sloped ground, the drain behind the wall runs to an outlet at or below the footing, and the discharge is placed so it does not reach a neighboring slope or the road.

Permits and rules in Mukilteo

Before quoting, we check each wall’s footing, its loads, and its placement against the state rule. The chapter 15.04 question goes to the city for any wall near the exemption line. Where stamped engineering is required, a professional engineer entitled to practice in Washington prepares it before the application is assembled.

Rules change and vary by parcel, so we confirm the current requirements with the city before we start.

How we approach it

Record the footing depth before the drawing is final
Locate every load that presses on the wall
Ask the city how chapter 15.04 treats the exemption
Place the drain outlet on the section

For the full process, see our Retaining Walls page.

Building in the cold months? See our guide to winter concrete pours.

Our retaining walls work, serving Mukilteo

Examples of our work. We build retaining walls in Mukilteo and the cities around it. See all of our work

Questions from Mukilteo homeowners

Where is the state wall exemption set for a Mukilteo wall?

The state rule covers a retaining wall not over four feet, measured from footing to top, with no surcharge and no impounded hazardous liquid of the classes it names. Mukilteo adopts its building code in chapter 15.04, and we confirm whether that adoption changes the exemption for your wall.

What counts as a surcharge behind a Mukilteo wall?

The state rule treats a load that presses sideways on the wall as a surcharge, so a driveway, slope, bank, or structure bearing on the back of the wall counts. A wall with a surcharge falls outside the exemption even when it stands under four feet.

When does a Mukilteo wall need stamped engineering?

We do not assume it always does. When the city asks for stamped plans, we arrange them through a professional engineer entitled to practice in Washington before the application is assembled.