Module 4: Foundations and Substructures 

1. Types of Foundations

Strip, Pad, Raft, and Piled Foundations

Choosing the Right Foundation for Soil Conditions

• Clay Soils → Use deep strip or piled (shrink-swell risk).

• Sandy/Gravelly Soils → Pad or raft (good drainage).

• Peat/Soft Ground → Piled or raft (avoids settlement).

• Rock → Shallow pad/strip (no need for deep excavation).

2. Concrete Work in Groundworks

Mixing, Pouring, and Curing Concrete

• Mixing:

• Ready-mix (for large projects).

• On-site mixing (small jobs, ratio control).

• Pouring:

• Vibrated to remove air pockets.

• Slump test checks workability.

• Curing:

• Kept moist for 7 days (prevents cracking).

• Covered with polythene in hot weather.

Reinforcement (Steel Mesh, Rebar)

• Rebar (Steel Bars):

• Tied in grids for tensile strength.

• Covered with 50mm concrete to prevent rust.

• Mesh (A142, A193):

• Pre-fabricated sheets for slabs.

• Lapped by 300mm for continuity.

3. Waterproofing and Damp Proofing

Membranes and Coatings

Importance for Substructures

• Prevents water ingress (mold, structural damage).

• Avoids rising damp in walls.

• Protects steel reinforcement from corrosion.

Conclusion

This module covers foundation selection, proper concrete techniques, and waterproofing—essential for durable, stable structures. The next module discusses final site preparation and handover.