Question:

Asalaamu alaykum,
Next to my work place we have a small musallaa wherein three to four fardh salaah take place and athaan also takes place.  My boss wants us to start praying jumuah.  Would it be alright because not all 5 salaah take place?

Answer:

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.

Jumu῾ah will be valid with the followings conditions: 
1)    Jumu῾ah salāh takes place in a city or in the outskirts of a city
2)    There has to be an imām to lead the salāh
3)    It must take place in the time of zuhr
4)    The khutbah (sermon) must take place in the time of zuhr prior to the salāh.  There must be at least one person to listen to the khutbah.
5)    General consent for people to attend.
6)    A congregation of at least three men besides the imam.[i]

It is not necessary for Jumu῾ah salāh that it be performed in a masjid.  However, the reward acquired in a masjid will be greater than that of a musallā.  In conclusion, as long as the above conditions are met, the performance of Jumu῾ah in a musallā where not all the salāh take place will be valid.[ii]
 
And Allah Ta’āla Knows Best

Mufti Faraz Adam
www.darulfiqh.com