Wine Cellar Conversion

Converting a damp unused cellar for another use has become a popular form of home improvement.  Conversion to a wine storage cellar is a very popular option.  

Cellars are naturally cool humid places not subject to the wild temperature fluctuations that occur above ground and many people choose to use the cellar in its original condition. This may be OK for short-term storage and for relatively inexpensive wines, but for long-term storage of fine expensive wines it is important to eliminate natural daylight and to achieve accurate control over the temperature and humidity.

Waterproofing cellar with cavity drainage membrane and render.

A sump and pump system is installed (far corner) and a wall floor joint drainage channel is installed (Waterguard) - visible as a grey strip at the wall floor joint.

Once the new floor slab is laid, with waterproof floor membrane, the cellar is ready for fitting out.


See full case history of this wine cellar conversion

The daylight issue is easy, cellars are often devoid of natural light any way and you can block up or put shutters over any windows that there might be (please note that if the cellar is to be classed as living accommodation in any way an escape window must be present in order to comply with building regulations).
Some wine cellars occupy the whole of the cellar space, often these are 'under pavement vaults' or small cellars, which were, perhaps the original coal cellar. In these cases the whole cellar must have a totally controlled environment, which means an airtight door, is required. Airtight doors made of lacquered steel with thick layers of insulation are available for this very purpose. Certain models come with a heating and air conditioning unit built into them, which is an ideal way of achieving total environmental control in one go.   Otherwise a separate heating, ventilating and air-conditioning unit will need to be installed which vents to the outside of the cellar.
These units are capable of controlling the temperature to within 3 degrees Celsius, which is the normal range for a good quality wine storage environment. Of course it makes sense to insulate the cellar as best you can in order to minimise the energy use of the temperature control unit. This can be done using traditional insulation methods and by using an insulated membrane for the waterproofing such as ThermalDry Wall Floor membrane. 

Where the wine storage area is to be only part of a larger cellar you may not want to have the other parts at the same temperature as the wine area and you may also wish to have natural ventilation and daylight in the other areas. Indeed if the other areas are to be used as part of the living accommodation, there will be building regulations requiring you to have these features, which would clash with the requirements for wine storage. In such cases a 'wine vault'

may be the answer. These are literally prefabricated airtight rooms (the size of a very large cupboard) , which can be assembled, down in the basement and include insulated wall panels and door with the heating and air-conditioning unit built in. They represent a very neat solution for the multi-purpose cellar conversion, where wine storage is only a part of the overall usage.

To find out more information on these systems see see wine storage systems

Cellar Tanking how to avoid the problem of ground salt attack from damaging cement based waterproofing systems

Cellar Tanking is a term used to describe the waterproofing of a cellar, it is often applied as part of a cellar conversion project or may be installed on its own to create a dry storage space.

By definition, cellar tanking systems are bonded to the walls and floor of an otherwise wet cellar, with the aim of holding back water or dampness, to produce a 'waterproof tank'.

Ground water contains dissolved salts, particularly Nitrates, Chlorides and sometimes Sulphates. They can affect cement based tanking systems in two different ways:

* Sulphate Attack of Cement
* Growth of Salt Crystals (Chlorides and Nitrates)

Examples of Ground salt attack on cement render tanking systems

1. Sulphate Attack

This is a reaction between the Sulphate and the Calcium Hydroxide and Calcium Silicate hydrate in the cement paste, it results in cracking, expansion and loss of bond between the cement paste and the aggregate with ultimate failure of the tanking system.

Sources of Sulphate include:

* Seawater (so be wary in coastal areas)
* Oxidation of Sulphide in adjacent clay
* Bacterial action producing Sulphur dioxide, which dissolves in water and then oxidises to produce Sulphuric acid.

2. Growth of Salt Crystals.

These can grow within or behind the render of the tanking system itself causing the render to crumble or delaminate. Why do salt crystals grow and what do they look like? The answer to this is simply that ground water contains dissolved salts and as the water evaporates the salt gets left behind, just like it does on a kettle element. So any 'breathable' render will allow salt crystals to be deposited at the point of evaporation, which may be within or behind the render. They are normally white in color but sometimes have a yellowy tint. If water is evaporating from the surface of the wall they will appear as wispy filaments that often get mistaken for mold.

In order to avoid the risk Sulfate attack the ground water should be tested for Sulfates, and if found to be present, a tanking system should be selected which is non-cement based. If cement based tanking material must be used, for whatever reason, then a salt inhibitor based on Zinc hexafluorosilicate (also known as Zinc hexafluoride - ZnSiF6) can be used, it is available under various brand names and is easily obtained from most specialist material suppliers. This should be applied to the masonry before the cellar tanking slurry or render. Particular attention should be paid to the health and safety data which will normally be supplied with the the product.

In order to avoid damage by the growth of salt crystals a tanking system can be selected, which is non-breathable, a bonded sheet membrane would fit this category but be aware of limited ability to hold back water pressure. A non-bonded plastic or foil lined cavity drainage membrane is the best, as these allow water pressure to dissipate - see my other article on 'cavity drainage membranes'.

Of course anything that does not breathe is at risk of condensation in certain circumstances and I have written another article on this very issue.

To learn more about this subject I have prepared an on-line guide to Waterproofing Existing Basements and for those who do not have time to learn everything I have produced the 60 second Basement Waterproofing University where you can get the key facts in just a minute! Pass the test and qualify for £100.00 worth of vouchers towards your basement waterproofing project

Cellar conversions Do's and dont's

Converting an existing cellar into a habitable room is a way of extending a home without reducing the size of the garden and avoiding the hassle and cost of moving house. Popular uses for converted cellar space include, home office, or study room, playroom for the children, home cinema, hobby room, spare bedroom, even an additional lounge or utility room.

The work normally falls into three stages :-


1. Structural works (demolition of partition walls, digging down to create additional headroom)

2. Waterproofing and

3. Finishing works such as plastering and joinery, electrical and plumbing works.



The basis of a successful project is getting the waterproofing system right, if this fails everything gets ruined. The industry has seem much innovation in recent years and there is a useful document 'a Guide to Waterproofing existing basements' by Raymond Foulkes - published by the British Structural Waterproofing Association. The rest requires no more than traditional building skills. Be aware though, if more headroom is required, the existing foundations may require underpinning, this can be an expensive and time consuming part of the projects as it involves heavy manual work, basically putting additional concrete underneath the existing foundations - one bit at a time.

The concept of cellar conversions is one that has grown in popularity over recent years, especially with the increases in stamp duty, the requirements for home buyer packs and other obstacles that the government has put in the way of moving house. Add to this the recent difficulties of finding a buyer and obtaining a new mortgage and the idea becomes even more attractive. For many people, the need for more space is real but they like their existing home, they have put work and love into making it what they want and simply do not want to move. They may have already converted the loft and the only way now is to go down!
The more complex and expensive projects involving underpinning are more common in areas where real estate values are high, many parts of London and other up market neighborhoods in cities around the country, Leeds and Manchester in particular. However if we take into account the cost saved in not moving house it can make sense even if the added value is less than the cost of the conversion, so there has been a growth in this type of project in most parts of the UK in recent years.

So when is the best time to undertake such a project? Well, before you actually need the space is advisable. Don't wait for that baby or elderly relative to arrive, before you start the work! You may find that you have to give up some living space on a temporary basis to facilitate the work itself. Now is a good time as most specialist companies have cut their prices due to the recession and there are some bargains to be had, but this won't last forever and prices will rise again as soon as we start to come out of recession.


Do's and Dont's of Cellar Conversions

Do employ a true specialist for the water-proofing.

Do not rely on advice from your builder, friend or even architect when it comes to designing the waterproofing!

Do read the various guides that are in print so that you can evaluate the various opinions that you may encounter.
Do not employ a firm that has not heard of the British Standard BS8102, the BSWA Design Guide 'Waterproofing Existing Basements' and the NHBC publication 'Basements for Dwellings'

Do make sure that you have a sump and pump include in your system, even if your cellar has not history of flooding (yet)

Do not choose your basement waterproofing system based on price alone, you may live to regret it and find it is not the cheapest in the long run!

Do make sure that you comply with Local Authority building control, party wall legislation (if applicable) and obtain any necessary planning consent, especially if you intend to sell our property with the converted cellar as part of the living space.

Do not lower the floor without at first taking the advice of a structural engineer - you may require underpinning!

Do read the terms and conditions of contract carefully, whilst it is normal to allow a contingency for unforeseen items try to make sure that most things are included rather than excluded by the terms and conditions.

Do not let the 'lowest price' seduce you into signing a contract that may prove to have a higher final bill than you thought.

Do make sure that you take up references and even go to see finished work of the firm that you intend to employ.

Do not be fooled by a slick sales presentation and glossy brochures alone.

Do ensure that you include adequate natural light, ventilation and a secondary means of escape.

Do not leave moving of gas and electrical services to the last minute, it can take months to organize this!

Do choose a firm that offers an on-going after sales service.

Do not be put off at the thought of maintaining a pump; cars, washing machines and central heating systems all need maintenance and that is not normally considered to be a problem. A waterproofing system that cannot be repaired or maintained CAN be a problem!

Do keep your neighbours informed and on your side, and plan the works with consideration for others, cellar conversions can be be disruptive at the best of times!

Ask the author a question about your cellar conversion.

Ray Foulkes has served several years as technical officer for the British Structural Waterproofing Association and is author of the design guide 'Waterproofing Existing Basements'
Through his group of companies he offers a full design and installation service as well as a unique range of products for DIY installation.

He pioneered the use of proprietary underfloor channeling systems and the use of thermally insulated membranes for basement waterproofing and imports products from around the world for this purpose including the Grate range of basement waterproofing systems