I am tearing my chimney down to roofline and rebuilding, all in all it will be about 8' vertical of chimney. Using modern (new) brick, 3/8 mortar joints, and type N mortar. How much vertical height can I do in one day before I need to stop to let the mortar on the lower layers set up? And how long do I need to wait for it to set? And if I needed to sit on top of the chimney to have a good angle to put a liner in, how long should the mortar set before that?