Why period fireplaces behave differently

An original Georgian or Victorian fireplace is not simply a hole in the wall. Many have a wide, shallow opening, a generous chimney breast that soaks up heat, and a flue built from unlined brick, sometimes parged with lime mortar, sometimes shared with a neighbouring property. They rely on a strong, steady draught, and that draught depends on chimney height, the air supply in the room, wind direction and the weather.

The simple test is observation. Once lit, smoke should clear steadily up the chimney within a few minutes. If it spills into the room, curls back, or the fire sulks, something is wrong: a blockage, a cold flue, too little ventilation, or a downdraught. Older houses are often draughty, which helps, but if you have fitted draught-proofing, double glazing and extractor fans, you may have removed the very air the fire needs. A dedicated air vent near the hearth or a window left slightly ajar on mild evenings can solve an apparently stubborn fireplace.

Sweeping is not optional

Book a chimney sweep every year, ideally in late summer before the first cold snap catches everyone out. As a working rule, a wood fire or a fire burning smoky fuel should be swept twice a year, and bituminous coal more often still. Soot, tar, cobwebs and summer bird nests all restrict the flue, and a restricted flue is the most common precursor to a chimney fire.

• Ask the sweep to carry out a smoke test so you can see where any leaks are.
• Have the flue inspected by camera every few years, particularly if you have moved into a property with no paperwork.
• Fit a bird guard or cowl where the flue is vulnerable, but never one that reduces ventilation.
• Keep a written record of every sweep — insurers frequently ask for it after a claim.
• Never assume a swept chimney is a sound chimney. Sweeping clears deposits; it does not repair cracked parging or failed liners.

Keep the hearth and surround clear

Give the fire room to breathe. Allow at least a metre of clear space in front of an open fire, and follow the maker's clearance instructions for any inset stove or insert. Combustible items creep into that zone over winter: drying washing, stacked logs, newspapers, magazine racks, curtains, and a fender loaded with kindling.

Where children or pets share the room, a substantial fender and a spark guard are essential, and they should be secured rather than merely propped in place. If you use an open fire, keep ash and embers contained. If your property is listed, remember that altering the surround, hearth or chimney breast may need consent, and original materials such as lime plaster, stone or cast iron are best conserved rather than replaced.

Choosing and storing fuel

Wet wood is the enemy of both efficiency and safety. Burn wood at below 20 per cent moisture content, tested with a cheap moisture meter on a freshly split log. Kiln-dried logs or timber seasoned for twelve to twenty-four months will do; softwoods are fine if genuinely dry, though they burn quickly. Never burn painted or treated timber, driftwood, or household rubbish, which clog flues and release corrosive compounds.

In a smoke control area, check with your local council about which fuels are permitted, and use authorised smokeless fuel where required. Store logs off the ground, covered on top with the sides open to the wind, and away from the house wall so damp cannot travel into the masonry. Never stack firewood against the chimney breast indoors, and remember that coal wants air from below while wood prefers a bed of ash.

Let ashes cool in a metal container for at least forty-eight hours before disposing of them, and keep that container off anything combustible.

Running a fire well

Warm the flue before you commit to a big fire. A small, bright kindling fire with the air control fully open establishes the draught and drives off any lingering damp. Build up gradually, and avoid cramming the grate full. A hot fire burns cleanly; a smouldering one coats the flue in tar, and slumbering a fire overnight is the single biggest cause of chimney fires in period homes.

Close the damper or air control only when the fuel has genuinely died down, and never leave a fire unattended with the doors open.

Chimney fires, thatch and alarms

A chimney fire often announces itself with a low roaring like a distant train, sparks or smoke at the pot, an unusually hot chimney breast, or a burning smell in an upstairs room. Do not throw water on the fire. Close the appliance's air controls, move everyone out, and call the emergency services. Have the chimney swept and inspected before you light it again.

Thatched properties need particular care: the chimney must extend well above the ridge, a spark arrestor should be fitted, and sweeps should be more frequent. Finally, fit carbon monoxide alarms in any room with a solid fuel appliance and test them weekly. A working alarm, a clear hearth and an annual sweep are the three habits that keep an old fireplace a pleasure rather than a risk.