I would suggest using a water based poly on chalk paint if it is going to be near heat.
Chalk paint over marble fireplace.
Mary did a great job.
She used french linen chalk paint on the floor tiles and then ran a wash of pure white and water 1 part each over the dried french linen and immediately wiped off the excess.
Like most water based paints chalk paint takes weeks to cure.
Paint the marble with your chosen chalk paint colour using a chalk paint brush.
Kristin young totally transformed her fireplace surround using old white chalk paint by annie sloan.
I used the same wash on the brick fireplace.
Don t confuse chalk paint with chalkboard paint which creates a surface that mimics a chalkboard and allows you to write on it with chalk and remove your jottings with an eraser.
Apply a soft wax over the painted marble if you wish.
Apply the second coat of chalk paint again relatively thinly.
In hot weather wax gets sticky and tacky.
Allow six weeks or longer.
Leave to dry for a couple of hours.
So we went neutral.
I would assume the same thing might happen on a fireplace surround or mantle.
It will make the poly chip and peel.
Poly will work fine on chalk paint but never put poly over chalk paint that has already been waxed.
This budget friendly 25 fireplace update can be done in less than a weekend.
Get step by step instructions and tips to paint a marble fireplace surround using chalk paint including which brand holds up to the heat.