How to Build a Strong Foundation in Sandy Soils: Tips for Somali Coastal Construction

 If you’ve ever built  or thought about building near the coast in Somalia, whether it's in Mogadishu, Kismayo, Bosaso, or Berbera, you’ve probably heard one warning over and over: “Beware of sandy soil!” And honestly, that’s good advice. Sandy soil is tricky  it drains water quickly, doesn’t hold its shape well, and can cause foundations to shift or settle unevenly.

But here’s the good news: building on sandy soil is not impossible  you just need the right approach. I’ve worked on several projects along Somalia’s coast, and today, I want to share practical, real-world tips to help you or anyone interested in construction make solid choices when dealing with sandy ground.

Why Sandy Soil Is a Challenge (But Not the End of the World)

Let’s break it down first. Sandy soil, especially along the Somali coast, is loose, dry, and doesn’t bind well. That means:

• It shifts easily, especially during heavy rains or tremors.

• It doesn’t retain moisture, which affects how concrete cures.

• It has low bearing capacity, meaning it struggles to hold heavy loads like buildings.

So if you build a house the “normal” way on this kind of soil, you might start to see cracks in walls, tilting foundations, or even complete failure after just a few years.

But don’t worry with the right foundation techniques, you can build strong, lasting structures, even on sand.

Tip 1: Get a Soil Test Always

Before you even think about laying blocks or pouring concrete, get a proper soil test done. This tells you how deep the sandy layer goes, how compact it is, and whether there’s firmer soil underneath. In Somalia, some local engineers or universities can help with affordable testing. It might cost a bit up front, but it saves thousands later.

I once skipped a soil test on a small guest house project big mistake. The back side started sinking during the rainy season, and we had to tear down part of it and redo the foundation.

Tip 2: Use the Right Type of Foundation

Once you know what you're dealing with, choose the right kind of foundation. Here are three that often work well in sandy soils:

1. Deep Foundations (Piles)

For bigger buildings or where the sandy layer is deep, consider using pile foundations. These are long columns (made of concrete or wood) driven deep into the ground until they reach more stable soil. They're more expensive, but they’re super strong.

2. Raft (Mat) Foundations

For smaller buildings like homes or shops, raft foundations spread the load over a large area. Think of it like a big concrete slab that "floats" on the sand. It reduces pressure on any one spot and helps the structure stay balanced.

3. Strip Foundations with Compaction

If the sandy soil is shallow and there’s firmer ground below, you might use strip footings, but you’ll need to compact the soil properly first. Use machinery to compress the sand layer, making it more solid before building.

Tip 3: Compact, Compact, Compact!

Compaction is everything in sandy soils. Loose sand must be tightly packed to support any structure. If you skip this step, no foundation will save you. Use vibrating compactors, and do it in layers water can help bind the particles a bit during compaction.

Tip 4: Use Moisture-Wise Concrete

Since sandy soil drains water quickly, it pulls moisture from your concrete during curing and that’s a problem. Dry concrete cracks and weakens fast. To avoid this:

• Use a slightly wetter concrete mix.

• Keep it moist for at least 7 days after pouring.

• Cover it with plastic sheets or water it regularly.

Tip 5: Consider Adding Geotextile Fabric or Stabilizers

Geotextile fabric can act as a barrier under your foundation to keep the sand from shifting. There are also chemical stabilizers or cement-sand mixes you can use to firm up the soil before laying a foundation. These aren’t always needed, but they can be helpful in extra-loose sandy zones.

Tip 6: Don’t Forget Drainage

Sandy soil is great for drainage until there’s too much water. Then, it can erode underneath your building. Add proper gutters, soak away pits, and sloped surfaces around the building to guide water away. Trust me, rain can undo all your hard work if you ignore drainage.

Final Thoughts: Build Smart, Build Strong

Building in sandy soil isn’t just a coastal issue  it’s a national challenge for many Somali cities. But with smart planning, the right foundation type, and solid execution, it’s 100% possible to build safe, lasting structures on the coast.

If you’re thinking of building, don’t cut corners. Invest in soil testing, talk to local engineers, and make sure whoever’s doing the job understands the challenges of sand. You’re not just building a house or office you’re building something your family or community will depend on for years.

And if you’re a young Somali interested in construction, coastal building is one of the areas that will need experts more than ever. So study up, get hands-on, and maybe one day, you’ll be leading big projects along our beautiful Somali coastline.