Getting drainage right under your tarmac driveway isn’t glamorous, but it’s absolutely crucial. Poor drainage will have your lovely new surface cracking, sinking, and looking tatty within a few years.
Most homeowners focus on the surface finish and forget what’s underneath. That’s a mistake that’ll cost you later. Water is tarmac’s biggest enemy, and heavy rainfall means you can’t afford to ignore proper drainage system planning.
Before You Commit: Essential Drainage Considerations
Walk around your property after heavy rain and note where water naturally flows. Check if neighbouring properties have drainage issues. Look for signs of standing water or boggy ground where your driveway will go.
Consider these key factors before any work begins:
- Natural water flow patterns across your property
- Existing drainage systems and their capacity
- Soil type and how quickly it drains
- Local planning requirements for surface water disposal
- Connection points to existing drains or soakaways
Questions to Ask Your Contractor
Don’t let anyone start laying tarmac without discussing drainage properly. A good contractor will assess your site’s drainage needs as standard, but you should still ask the right questions.
Make sure you cover these points:
- How will surface water be directed away from the tarmac?
- What depth of sub-base is needed for your soil type?
- Will the driveway slope be sufficient for proper runoff?
- Are additional drainage channels or gullies required?
- How will they connect to existing drainage systems?
- What happens if they discover drainage problems during excavation?
The contractor should be able to explain their drainage strategy clearly. If they seem vague or dismiss drainage concerns, find someone else. Proper drainage isn’t optional, it’s fundamental to a long lasting tarmac surface.