Removal of internal wall

I want to remove part of a brick wall in my upstairs of my house. Above the wall is the loft and the water tank is near the position of the wall, the wall does not carry on into the loft. the loft beams run across not paralell, but the water tank sits near the wall i need taking down ( not the whole wall just a quarter of the whole wall), my loft is small and i have dormers coming up from my house so i am not sure if the wall is supporting the roof. I just need to know if i could get away with using concrete lintels and not steel. Thanks Dan