deck oven issues with sourdough
been using a larghe old tom chandley deck oven for the last 3 months and it has alot of hot/cool spots which is fine. It has a broken steam injection which i havent been able to afford to get fixed yet however i spray on preload and after load and colour is fine and yeasted breads rise perfectly. I bake straight on the stone and generally i have good spring however my sourdoughs can be inconsistent in their rise so im looking for advice.
I currently bake at 440-450F and have top element at 4 and bottom at 1. I open damper after 20 minutes and finish bake.
When I started with this oven I had bottom element at 2 but then thought id play it safe instead of burning bottom of loaf. These days I sometimes get flatish sourdough loaves.
So my question is this:
should i increase bottom element
should i increase temperature and then move breads to a cooler spot in oven after 10/15 minutes?
if i increase temperature to maximise oven spring when can i open deck to move breads (i.e. can i open deck after 10 minutes and move breads to cooler spot without compromising rise)
has anyone any advice?