nail puncture through the tyre-advice needed

paul.d
paul.d Posts: 82
edited May 2008 in Workshop
I may just be luckky but in nearly 10 years of cycling I have just had my first nail puncture-rear tyre slow speed coming off a roundabout-replaced tube and got home but am not sure whether it's wise to keep the old tyre or should I replace the tyre? Thanks in advance