Fireproofing wooden beam

[vivyan]

What is the best way to fireproof an old oak beam over an open fire. I have heard of something called master board but cannot locate the product.
All sugestions gratefully received-Vivyan

 

[Scrit]

I'd have said move the fire elsewhere! Could you perhaps explain what you are trying to achieve, please?

Scrit

 

[BOB NUTS]

do you want to have the oak beam as a visual feature?

or are you happy for the beam to be covered over?

 

[vivyan]

do you want to have the oak beam as a visual feature?

or are you happy for the beam to be covered over?

The fireplace is very old and the overmantle beam is a feature of it so I would rather not use the fireplace than cover it over completely although covering the back and underside would be acceptable.
Vivyan

 

[JohnD]

I'm thinking of a folded steel plate, with a couple of layers of plasterboard inside, to cover the underside and back, with a generous overlap so that no spark can get inside. The steel is to protect the plasterboard from impact, and from getting so hot that it crumbles.

In older houses it's very common to find the wooden beam has beeen on fire. It will be very dry and can smoulder for a long time. You won't smell it.

I believe you mean the beam that spans the fireplace and supports the chimneybreast? You also used the term overmantel, which I understand to be outside and above the hearth opening and is non-structural, so not the same thing.