would like to add a sill plate to interior block wall above window
as bricks inside are sagging.
Where can i buy this peice of metal?
Is it correctly called the sill plate to hold the bricks secure and level and keep the load off the window?
The sill would be the bottom of the window opening not the top as I think you mean.
What your looking for I think is a lantel. May have miss spelled it.
Any real concrete company, Lowes and Home Depot have them in the concrete area.