BS 1251 discusses open-fireplace components. A fireplace is typically made up of four parts: the firebox, the masonry chimney, the smoke chamber, and the roof. The firebox is where you put the logs and light them on fire.
The masonry chimney is what vents the smoke out of your house. BS 1251 specifies requirements for components which, when assembled in accordance with BS 8303, form the setting for inset open fires of nominal sizes 400 mm and 450 mm.
BS 1251 on open-fireplace components is useful for:
The firebox, the interior of the fireplace, contains the fire and collects the smoke. The flue is the passageway at the top through which the smoke and gases travel for the exit. Flues are often made of baked clay but can also be stainless steel.
BS 1251 guides you with the design, dimensions, heat resistance, and installation of firebacks. BS 1251 guides you with the prefabricated fireplace surrounds and hearths, throat forming lintels, and marking. BS 1251 helps you to manufacture high-quality open-fireplace components.
BS 1251:2015 supersedes BS 1251:1987 which is withdrawn. BS 1251:2015 includes some technical changes with respect to BS 1251:1987. These include: