Hey all! New build in the PNW and our driveway has a bit of washout after some crazy rains. Initial low cost plan would be to use some huge dunnage beams and line the steep side and drive them in with rebar. Could also just do asphalt?
Solutions?
by Which_Comfort651
4 Comments
I would go with asphalt. I have built many retaining walls and the material and labor for a drive the long would be crazy.
Asphalt is a waste of money until you stabilize that shoulder. If the base settles or washes out from underneath, the asphalt will just crack and slump right off the hill. Dunnage and rebar is a temporary fix that buys you maybe five years in the PNW before the wood rots or the wet soil pushes it over. You need to manage the water first by creating a slight berm on the driveway edge to guide runoff to a safe discharge point rather than letting it sheet over that loose fill.
For the slope itself large angular rip rap is usually your best bet here since it drains naturally and locks together under load. Before you commit to hauling heavy timber or rock, run the site photo through GardenDream to visualize how a rock armor slope looks compared to a vertical wall. It helps you see if you actually have the width for a proper slope or if you need to engineer a vertical solution to save space. Whatever you choose, get deep rooting natives like Nootka Rose or Snowberry into that bank immediately to knit the soil together.
Stabilizing the slope with native grasses is going to be a big deal for erosion control on a budget.
Retaining wall here is going to be upwards of $50k, surely.
A living retsining wall would look amazing. These are DIY…
https://www.verdtech.com/retaining-wall/
https://filtrexx.com/en/products/greenloxx