Muddy Mortars


If there is one feature that defines the Cornish cottage, it has to be the inglenook fireplace.

Before stoves and ranges were in common use, cooking was traditionally done over an open fire and in Cornwall that fire would have been made in a cob or stone inglenook fireplace.

Inglenook fireplaces are typically quite grand; often two metres wide, a meter and a half high, and a metre deep. Two stone columns flank the hearth area, and a granite or timber lintel should span the front. They would originally have been mortared with clay or lime, but are now often hidden under layers of plaster.

They make for a fantastic and unique feature when exposed and traditionally restored and apart from their aesthetic attraction, there are strong benefits to the building to be had from uncovering and restoring them in a traditional manner with lime and other breathable materials.

Why Hidden Fireplaces are a Cause of Damp in Old Buildings

When we expose old inglenook fireplaces, they are almost always very damp and filled with rubble, old bird nests, and soot. In some cases we have removed two tonnes of this detritus before we have been able to begin rebuilding and restoring. This detritus is one of the reasons why a sealed fireplace is a high risk area for moisture build up.

Another reason is that as flues in granite cottages lie within the stone walls, there is little to prevent wind driven rain penetrating the stonework and passing into the flue and the fireplace void. If the chimney is leaking or has open pots, this also creates a point for moisture to enter the flue. Once moisture is in an unvented flue, it can condense and drip down to saturate the contents of the fireplace void. It then has no exit point except to the inside of the house, where it may cause the humidity in the living area to increase and promote the growth of mould, fungi, and other microorganisms damaging to health.

This effect is particularly pronounced when non breathable finishes have been used instead of the traditional clay and lime finishes.

Benefits of Traditionally Restoring Hidden Fireplaces with Breathable Materials

When an inglenook is restored in the traditional manner with breathable materials such as lime, it allows for the passage of air into the fireplace and through the flue. This prevents damp building up, and results in better and dryer living conditions for the occupants of the building.

Every inglenook is unique; they vary massively in size and construction, but they all open a window into history.

Typically, they have been filled in over generations as cooking and heating technology changed – first they would have been used as an open fireplace, then maybe round 1900 they would have been partially filled in to make a space for a Cornish range, then filled in a bit more to fit a small open fire, and finally sealed off completely.

When we come to them they are completely hidden – no more than an unexplained protuberance in the wall.

Once they have been restored to their original form and the stonework cleaned and re-pointed, some pleasure may be taken in observing that one is looking at a feature that has not been seen in a hundred years.

As experienced lime masons operating in West Cornwall, we at Muddy Mortars can help you with all aspects of your traditional restoration and assist you in transforming your cold damp cottage into a cosy warm home. Get in touch if you'd like advice or a building assessment.

To get a quote or to arrange a building assessment, call us on or 01736 741272.