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Living with your French Home

As a practicing RICS Building Surveyor and Conservation Practitioner in France I get the opportunity to spend a great deal of time looking other people’s houses and as if that on its own weren’t pleasure enough, at the same time the opportunity to fulfil one of my great pleasures - historic buildings.

Now it could be argued that all buildings are historic to some degree and if one really wanted to split hairs, I would have to agree. But when I talk about historic buildings I refer to those built in the vernacular style – that is an indigenous building constructed of locally available materials, to local detail, usually without the benefit of an architect. Somehow it is now taken to imply a fairly humble or practical origin, but this is not the case.

Vernacular is often referred to as the ‘little tradition’ as opposed to the greater or polite architecture of national or international influence but this in itself of not correct for it is the regional buildings that give a place its sense of uniqueness.

Before we look at why many people get the restoration of older properties so wrong, we need to consider at what it is that makes these buildings unique in the first place. Is it the ‘exposed beams’ that we hear so many immobiliers waxing lyrical about or the lilting door openings or varying sizes, the beautiful inward opening casement windows with their quirky espagnolette fasteners or is it the fascinating, almost mathematically sized and placed limestone blocks that form the majority of Charantaise rural buildings with their deep clay-red earth joints or indeed the formidable square cut granite quoins vousoirs and reveals of the Limousin townhouse. In

truth it is all these things.

However, for some unknown reason, a great many people who buy properties with these same wonderful

features seem hell-bent on removing them, only to be replaced with modern double-glazed windows, laminate flooring, central heating, synthetic paints and cement mortar pointing.

An article published by the RICS in February 2006 highlighted how a massive number of old buildings in the UK (This list could just as easily apply to French properties) are being irrevocably damaged because of ignorance about traditional building skills and cited the following as the top ten botches:

1. Replacing original windows with inappropriate modern types.

2. The unnecessary use of injected chemical damp proof courses or improperly executed.

3. Encouraging damp, rot and insect attack through blocking vents and high external ground levels.

4. Removal of chimney breasts and other structural walls without adequate support.

5. Badly neglected mortar pointing

6. Re-pointing brick and stonework with the wrong materials.

7. Neglecting flashings around chimneys and abutments allowing moisture penetration.

8. Recovering slate roofs in heavier concrete tiles without proper internal support.

9. Failing to cap and vent disused flues or using fireplaces without first checking the condition of the flue.

10. Weakening timber floor and ceiling joists by cutting for cable and pipe runs.

My own personal desire to see these elements retained is not borne purely out of some misplaced dislike of all things modern – on the contrary, my own French home is only forty years old! No, the reason is much more practical. Older vernacular buildings last so well because of the materials their builder’s chose, not in spite of them. Most of this is finding the equilibrium between the various elements that exist within it which are;

Earth, water, fire and air.

These can be translated into modern day language as;

External walls (sometimes earth), moisture (produced from within and without), heating and ventilation.

Lime

There is not enough space here to fully cover this wonderful material and I would advise anyone who is interested to seek out more information on its use.  Don’t get me wrong, cement is a wonderful material if you want to build a motorway bridge or perhaps foundations. You simply add sand or aggregate and water in approximately the correct proportions, and within a few hours it begins to set and 28 days later it will have achieved its maximum strength. It is a material that is quite forgiving to those not entirely skilled in its use it is relatively easy to achieve a reasonable result with only a minimum of experience.

Rock solid in 28 days - what could be better?

The problem though is that old buildings, especially those built in the soft French limestones are not solid structures. Most are constructed upon the surface of the ground with no formal foundations and over their lifetimes, they move a considerable amount. Joints between the stones open and close with the seasons, roofs gradually spread and force out the walls, walls settle with age and that’s without the movement of the ground as it absorbs and gives up moisture.

Older properties are much more adept at coping with this movement being built as they are with more ‘fluid’ materials and less rigid forms of bonding one element to another. Thus it is possible for older properties to move a considerable amount without it being even apparent, the stone shifting and the lime mortar almost ‘self-healing’ as it gradually re-fills the small voids within formed by the movement.

One of the quickest ways to compromise an old property is to introduce modern materials into it without regard of how they are going to work with those that already exist. A prime example of this is re-pointing. I am frequently asked to survey properties that have been ‘renovated’ by well-intentioned individuals, and as the smiling agent meets me at the front door and proceeds to tell me how the current owners have lovingly restored the property my heart invariably sinks as I cast my eye over the acres of exposed stonework.

Where once there existed the beautiful mellow tones of powdery lime mixed with chunks of glinting coarse grit and a handful of warm red earth now sits a sea of bland grey cement and lifeless uniform sand – rigid and unrelenting. The problem is not just one of appearance; it is also one of practicality.

The pointing between stonework, and indeed brickwork fulfils a very important function. When water is absorbed through the face of any form of masonry, it has to eventually evaporate. Water will always take the path of least resistance and if the pointing is soft enough and free draining, the water will track through the stonework and evaporate out through the joints. If the pointing is made from hard cement, the

water will opt to evaporate out through the less dense limestone or brickwork. Over a long period of time the process of this evaporation will slowly cause the face of the stonework to crumble and flake away leaving the cement pointing looking as good as the day it was applied. As a rule, the pointing should always be less dense than the building stone.

Anyone doubting this should look at the front elevation of the Hotel de Ville in Ruffec in the Charente where repointing the limestone façade some years ago in cement has caused this process to occur. Alternatively if you are UK-bound, there are thousands of examples Victorian brickwork all over Britain where the soft faces of the bricks have literally fallen off leaving sharp well defined joints of cement mortar standing proud.

Another area where the use of lime is important is with the control of moisture within wall structures. The exterior loadbearing walls to most vernacular buildings are built directly upon the ground on which they stand and as a consequence they tend to draw up quite a considerable amount of moisture from the soil. This is a natural process and where lime or simply earth joints exist in the masonry, this moisture evaporates both inwards outwards quite harmlessly. Imagine now that a well-meaning restorer decides to repoint (or worse, render) the outside of the wall with a cement based material. The moisture is suddenly prevented from evaporating externally, so where does it go? That’s right, inwards.

I have often seen old properties that have suddenly developed quite bad apparent ‘rising damp’ to the external walls, only to discover that the previous owner picked out all that “nasty crumbly earth from the outside” and repointed it in cement. A final word about lime: If you move into a property that has a nice original lime plastered wall, please don’t go and paint it with a modern synthetic paint system or else you’ll undo all the wonderful work of the plasterer.  Make up a limewash with water, lime putty, linseed oil and a natural pigment of your choice and you’ll be enjoying the results for years to come.

Timber Floors

As I have tried to emphasise, the success of living in an historic property is to understand how it ‘works’ and to work in harmony with it. Achieving the balance between these elements is critical. A timber suspended floor within a property does two things. It provides a structure to walk on and also provides a space underneath where ground water can evaporate and (hopefully) air can circulate.

The new owners of old properties frequently opt to pull up an old rotting wooden floor and replace it with a

continuous concrete slab to provide a solid base on which to tile. Having lovingly undertaken this work they then wonder why they suddenly see moisture creeping up the outside walls six months later. The reason is that  all the moisture that previously slowly percolated out from the ground under the suspended floor and evaporated out through the gaps is now trapped under the slab (with damp-proof membrane as well sometimes) and has nowhere to go. Water will always take the path of least resistance and creeps outwards until it finds those lovely old walls built straight onto the soil and up it goes!

“Aha!” I hear you say, “But if that old floor was so rotten then surely a new one will rot just the same”. Well you can prevent that happening by making sure that your nice new timber floor is not in direct contact with the soil, has proper ventilation around the edges and that external ground levels are kept lower than internal levels, that drainage is properly sorted out and that dense clinging vegetation kept properly under control. All these factors will have a direct influence on the durability of your property.

Heating & Ventilation

I have placed these last two together because in many ways achieving the balance of either one is crucial to achieving the best environment for you and your historic home. Modern living has made us used to heating. Most of us expect central heating as the norm, and the prospect of living without it might send most of us running for our nearest Berghaus fleece. I am not going to suggest that we should huddle together in the depths of a Charente winter and rely solely upon that hugely inefficient feature fireplace where 93% of the heat goes up the chimney. But similarly, do not block up the fire place, install draft-proof double-glazed windows and turn up the thermostat.

A study by the BRE (the United Kingdom Building Research Establishment) arrived at the conclusion that

an ‘average’ family can produce up to 14 litres of airborne moisture per day. This is created through cooking, bathing, boiling the kettle and simply breathing in and out. A good deal of this will gradually percolate outside through open doors and windows but residual quantity will remain in the property and be absorbed into the building’s fabric. This is usually apparent by the appearance of black mould in cool corners where moisture laden air condenses back to water and causes the ever-present spores to germinate. Older properties tend to be less airtight than their modern counterparts and the proliferation of ill-fitting single glazed casement windows (the original dehumidifiers where water condensed) and two or three chimneys will ensure a regular air change within the building and thus help to dissipate the moisture created within it. By all means, install central heating into your period home but let it breath and help keep you and your French house healthy.

Conclusion

Building conservation is a vast subject that cannot be covered in such a short space and requires a reasonable depth of understanding of how buildings work. If you have lived your life in a modern post-war property then the idiosyncrasies of a stone or cob building with irregular walls built at alarming angles may be unsettling None the less, by following a few very simple rules the average home owner can ensure that they don’t cause irreversible damage to their aged property.

1. Always endeavour to repair rather than replace where economically possible.

2. If a defect exists, think logically about why it might be manifesting itself. Sometimes the simplest answer is the right one.

3. If replacement materials are required, try to replicate those that exist in the property. If you have a large

country property there may be piles of stone or roof tiles around the grounds that match those that were

used to build the house.

4. Above all, respect the building and work with it rather than against it.

Living in an old property with a long and varied history is a privilege. Part of the pleasure of any old building is  to ‘read’ the changes and repairs that have occurred over the years to build a picture of how the property and the needs of its various changed. Try to make sure that any changes that you make are equally readable so that in the future, others will be able to see what changes you made and carry on the tradition themselves.