It looks quite nice to be honest!
Was it there when you moved in?
If it was a diy job you might be lucky and find instructions for assembly online?
Often there are hidden metal brackets plastered over on tHe sides. Another option is that the mantelpiece sits over a void inside which are similar brackets pointing inside?
My fireplace was fitted by a mason, he seemed to glue it together using some sort of mastic /silicone in a tube.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local