The study found more than half (53 per cent) of under-35s admitted needing help with DIY, with 15 per cent of 18-35s saying they cannot carry out tasks such plumbing, cleaning, gardening or household maintenance.
Of 2,000 adults in the UK surveyed this month, 42 per cent did not know how to bleed a radiator and less than a third (31 per cent) considered themselves self-sufficient.
It also confirmed a sex difference – with 47 per cent of young women needing help with most household DIY tasks, compared with 29 per cent of men.
The older generation excel at more too. The poll found over-50s were three times more likely to cook Sunday roasts each week – 36 per cent compared with 11 per cent of 18-35s.
One parent in five cooks for their grown-up children more than once a week, while nearly a quarter (23 per cent) of young Britons who had left home have their parents help them with their laundry.
Almost half (48 per cent) of over-50s help their grown-up children financially, and many also provide practical help.
A spokesman for insurer Confused.com said: “In the event of a claim, insurers may not pay out on your home insurance policy if you have not taken steps to ensure your property is adequately maintained.”