i use a 20ft double alloy ladder from B&Q
what say ypu lot?
I agree with Gaza. B&Q ladders are designed for very limited use.
Your ladders should be to the British Safety standard of EN 131 (the ladders should have BS EN 131 stuck on the sides) and will have 'yellow feet'. What Gaza says about 'class 1 or 2' ladders is a little out-dated now, but true none-the-less.
I've fallen from a set of B & Q ladders - luckily enough I just received bumps, bruises and scrapes.
BS EN 131 ladders are heavier; which may take a little getting used to; but you'll feel far safer.
I'd say get a set of these straight away and consider a double pointer after.