An incontinent
    person should make a new wudoo’ for each obligatory prayer
Question

                I understand that a person who finds it
      difficult to remain tahir due to circumstances beyond their control, eg urination problem
      etc it is not necessary to continually clean up if it is too much of a strain and the
      person should do fresh wudo before every prayer. What if the prayer for some reason is
      prayed late eg if 'Asr is done 30 minutes before Maghrib, is a fresh wudo for maghrib
      necessary for this small time gap? Also if one does wudo for Juma'h prayer one hour early
      and sits in the mosque waiting for prayer is this wudo adequate or is another one
      necessary, if it is alright then will the wudo last all the way until just before 'Asr
      time?
Praise be to Allah.The person who is suffering from incontinence should make a new and
    separate wudoo for each prayer when the time comes, even if he has just made
    wudoo for another prayer a short time before. This is because the Prophet 
    taught the woman who suffers from istihaadah (prolonged non-menstrual vaginal bleeding) to
    do this. Aaishah said: Faatimah bint Abi Hubaysh came to the Prophet
    
 (peace and blessings of Allaah be upon him) and said: O Messenger of Allaah, I
    am a woman who experiences istihaadah and I do not become clean from bleeding. Should I
    forget about salaah? He said: No, that is from a vein; it is not menses. When
    your period starts, then stop praying, and when it ends, wash the blood from your body and
    pray again. Abu Muaawiyah said in his hadeeth: He said: Do
    wudoo for each prayer, until the time for the next prayer comes
    Abu Eesaa said: The hadeeth of Aaishah is a saheeh hasan hadeeth,
    and this is the opinion of more than one scholar among the Companions of the Prophet 
    (peace and blessings of Allaah be upon him) and the Taabieen. It is also the opinion
    of Sufyaan al-Thawri, Maalik, Ibn al-Mubaarak and al-Shaafii that when the woman who
    suffers from istihaadah finishes her regular period, she should do ghusl, then do
    wudoo for each prayer. (Sunan al-Tirmidhi, 116; the hadeeth was
    reported by al-Bukhaari, no. 221).
    Ibn Hajar (may Allaah have mercy on him) said: The
    ruling on non-menstrual blood (istihaadah) is the same as the ruling on anything that
    breaks wudoo: she should do wudoo for each prayer, but she should not pray
    more than one fard prayer with that wudoo, whether she is praying on time or is
    making up the prayer later, because of the apparent meaning of the hadeeth, You
    should do wudoo for each prayer. This is the opinion of the majority of
    scholars. (Fath al-Baari, Kitaab al-hayd, Bab al-istihaadah).
    The same ruling applies to the person who suffers from continual incontinence or wind. You
    can pray as many naafil prayers as you like with the wudoo you made for a fard
    prayer, until the time for that fard prayer is over. And Allaah knows best.