Construction profiles
Semi-detached / duplex
House type affects access to exterior walls, shared boundaries, drainage routes and how structural changes can be carried out.
What should be checked
How the investigation changes
Photograph the whole area and close-ups; note approximate building age, wall/floor construction, outside ground level and when the symptom changes. If water is involved, record whether it follows heavy rain, snowmelt, showering or is present continuously.
The decision changes with moisture source, structural condition, available height, drainage level, intended room use and whether the work affects load-bearing construction. Treat a product choice as the final step, not the first.
Typical points of attention
Rapidly growing cracks, active water, structural movement, sewage backflow or extensive mould deserve a more cautious assessment before finishes continue.
Structural, electrical, plumbing, geotechnical and health-critical work can require qualified professionals and local approvals.