In everyday practice, we see that customers come with a clear idea: they want a fireplace, a stove, warmth, atmosphere. However, it is up to the stove builders not only to listen to their expectations, but above all to reassess them professionally and translate them into a solution that makes sense in the long term - technically, functionally and aesthetically. And this is where the responsibility of a true craftsman begins.
Where are the most common mistakes made and what should a stove builder know? We asked Vít Pešek, vice-president of the Guild of Stonemasons of the Czech Republic.
Where are the most common mistakes made?
Out of ignorance. When a stove builder doesn't have the proper training.
What should a stonemason know?
Must be able to size heaters. They must understand how wood burns. They must understand heat and the principles of heat distribution and insulation. Know standards, stove technology and working practices, materials, binders. They must be able to express themselves graphically and be able to draw up appropriate technical documentation. Must be able to plan subcontracts, materials for construction and other deadlines. Last but not least, he must be able to work with stove materials and build the heater.
That seems like no small feat indeed. Are there any standards for stoves and fireplaces?
Sure. There are several. We have a standard for stoves, CSN 72 4710. The different types of heaters are so different from each other that we have a separate standard for each type. CSN 73 4230 for fireplaces, CSN 73 42 31 for stoves and CSN 73 4232 for cookers. For the sizing of stoves, the European harmonised standard EN 155 44 applies. And the stove builder should be familiar with all these regulations.
How should the layman - the customer - proceed when choosing a fireplace?
Not only when choosing a fireplace, but when choosing any heater, it is best to follow the "stove builder's ten".
1. WHICH HEATER TO CHOOSE?
First of all, make it clear to yourself what you expect from your new heater and why you are buying it in the first place. Are you primarily interested in cooking, baking? Maybe you just want to sit by the fireplace and look into the flames? Or do you buy a stove to heat? If you prefer a heating function, is it to be the main source or rather an alternative secondary source? And maybe you'd like to put it all together? Is the new heater to provide trouble-free home heating even in the event of blackouts and to strengthen your independence from the electricity grid?
2. HOW TO CHOOSE A STOVE BUILDER?
You can find your stonemason on the website of the Guild of Stonemasons of the Czech Republic in the section Search for a stonemason. You can either contact someone from the nearby area or you can choose a specialist within the country who builds heaters according to your taste. The advantage of the stonemasons associated in the guild is the emphasis of the community on stonemasonry education, exchange of information, professionalism and quality of work. The Guild of Stove Builders of the Czech Republic is a member of the European Association of Stove Builders, and cooperates in industry legislation, research and development of heaters. The members of the Stonemasons' Guild have access to this modern stonemasonry knowledge and can use it in their practice. When solving a problem, the Guild offers customers and stonemasons the institute of the so-called Guild Technician - an independent professional arbitrator whose interest is to objectively assess and describe the situation and propose a viable solution.
3. FIRST MEETING WITH THE STONEMASON
The first meeting is usually at the stove builder's, it serves to collect data and information about the client's needs and intentions. The customer should receive from the stove builder a clear explanation of the characteristics and possibilities of the different types of stove construction and a proposal for the optimal technical solution of the heater. This first consultation usually has no concrete output in the form of a drawing. However, the approximate cost of the type of heater planned should be given. However, this will be a very imprecise indicative figure as it is not possible to determine a specific amount due to a number of unknown factors.
Bring the drawings of your building to the first meeting. The stonemason will use it to draw the information needed to calculate the heat loss, the correct sizing of the heater and its optimal positioning in the space.
4. SECOND MEETING WITH THE STONEMASON
If a specific technical form is chosen, it is possible to proceed to the creation of the heater shell. This is usually the subject of a second meeting. Here, the style, shapes, colours and finish are discussed. The outcome of this consultation is usually a hand sketch of the future heater shell.
To discuss the design of the heater, it is a good idea to select a few images of the heater to serve as inspiration for the aesthetic design of the shell. It is also advisable to inform the stove builder about the idea of the interior design of the room where the heater will stand.
5. DRAFT TOPIDLE
On the basis of the information from the previous meetings, the stove builder will draw up a design of the heater, from which the exact shape and arrangement of the internal structure will be clear. The design will include the specific components needed for the cladding and the internal construction. This will include all necessary calculations, both thermal and internal construction parameters. Creating a meaningful functional design, including dimensioning calculations and photorealistic visualisation, can take several working days for more complex structures. It is therefore not surprising that stonemasons usually demand a financial reward for the delivery of the overall design. Depending on the complexity of a particular project, this usually ranges from CZK 5-10 thousand. If several alternative options are created, the price increases proportionally. In the case of the implementation of the heater, this item is of course deducted from the total final price.
At this stage of communication, you can still choose the colours, patterns on the tiles, the size of the doors and other minor adjustments.
6.BUDGET OF THE WORK
Once the final form of the work has been agreed, the stonemason can draw up a budget that covers all chapters of the work from the preparatory work to the actual construction. For this reason, in individual stonemasonry it is not possible to set the price in advance.
7. AGREEMENT
If the budget is agreed, the contract comes next. In addition to the usual parts, it should contain the technical specification of the heater, i.e. the definition of its future characteristics. This includes the type of construction, the type of firebox, the method of control, the power output, fuel consumption, accumulation time or the cladding. There must be drawings showing all the relevant details, including dimensions, and ideally 3D visualisations. Individually built heaters cannot be tested in a test room, but must still meet the strict emission, efficiency and safety requirements of the relevant standards. Reference to these is also important when communicating with a chimney sweep or building authority. It may also be one of the conditions for obtaining state subsidies. If the stove builder does not design and build the heater according to the normative rules, it cannot be relied upon to be functional and may not be able to be operated when it is approved or otherwise inspected. The heater sizing report, i.e. a summary of the results of the calculations of the individual functional parts of the heater, should be an integral part of the contract. If necessary, drawings for other trades (foundation plan, building penetrations, water system wiring diagram, etc.) should also be attached to the contract documentation.
When signing the contract, require that it includes the technical specification, drawings, documentation on the sizing of the heater and a reference to the relevant standard.
8.IMPLEMENTATION OF THE HEATER
The design of the heater, including the selection and confirmation of all necessary parts and components, is completed. Now the stove builder must order everything he needs to build the heater from his subcontractors. Due to the fact that this is an individual job, the individual custom-made components need to be secured in advance. Normally, this can be several months, which must be taken into account in order to be able to implement everything within the agreed deadline.
The time for the actual implementation of the work depends mainly on the demanding nature of the heater. A smaller sized stove without a lay down will take skilled stonemasons approximately one working week, a tiled stove normally takes 14 days to a month.
9.FAMILIARIZATION WITH THE HEATER AND TENSILE TEST
Once the work is completed, the user is familiarised with how to operate the heater correctly. This also includes a tensile test. Most individual heaters cannot be fully melted immediately after erection. They contain a lot of water and the binders are not fully mature. Full flooding could disrupt the binder function and damage the heater. This is why the term tensile test exists in stove standards. The aim is to check that the smoke is leaving the chimney safely and that the heater is not fogging the room. Its successful passage confirms the functionality of the heater's draft test. Any deficiencies in heating function or design are only addressed after the heater has dried out and has been in full operation for some time under warranty.
10. HANDOVER OF THE HEATER
Upon handover of the heater, the customer will receive written instructions for use and a handover report from the stove builder. The handover report must contain a reference to the contract under which the heater was made, the signatures of both parties and the date of handover. The guarantee period starts from that date.
(When handing over the heater, ask for the instruction manual and handover report.)
That's a pretty comprehensive guide. And stove-making must be quite a complex field. Can a layman even tell that something is wrong with the contractor or his work?
Certainly, several clues point to this.
- If the supplier doesn't care about the heat balance and just sells what the customer points to.
- The same applies to the chimney and air supply. For the heater to fulfil its purpose, it should be operated under optimum conditions. The amount of fuel - this is dependent on the heat loss and the required accumulation of the heater. The amount of air for combustion. This is nowadays in most cases supplied from outside. In today's airtight buildings, air cannot be taken from the interior without pressure equalization. And, of course, the right chimney. Or the correct cross-section and effective height. If the chimney is of insufficient cross-section, the flue gases will not fit and smoke will be released into the interior. On the other hand, if the chimney has an excessively large cross-section, the flue gases "wander" in it, losing velocity and temperature, which leads to a reduction in draught, i.e. imperfect combustion, condensation in the flue and the risk of indoor air contamination.
- If the contractor cannot explain to the client the principles of how a particular heater works and why it will behave the way it will.
- If the supplier fails to provide the client with adequate documentation including calculations and drawings before signing the contract. The required documentation is clearly defined in the standards.
- Unless the supplier delivers a contract to the client that clearly states not only the price, but more importantly the technical specification of the heater. All the necessary terms can be found in the standards. It is a different matter if the client buys a manufactured heater such as a wood-burning stove. In this case, it is sufficient to assess the performance against the heat loss and to check that you have an adequate air supply and chimney. In contrast, individually built heaters - stoves, cookers or fireplaces are always original. For this reason, it is necessary to design them correctly in advance and to describe their future technical characteristics in the documentation. Including, of course, the corresponding drawings. The client should never buy something that he is not convinced that he knows how it will look and how it will work.
Do I really need to count anything when I want to buy a wood stove?
Of course. Each heater should have a capacity corresponding to the heat demand of the space to be heated. If the performance of the heater is less than the heat requirement, you will be cold and tend to overheat the heater, which will have a major impact on its lifetime. If the output of the heater is disproportionately greater than the heat demand, you will be so hot that you will not be able to operate it in optimum mode. You will tend to add less wood than it is built for, which will result in black glass but more importantly, rapidly reduce combustion efficiency. This means you will burn more fuel for your wallet, plus you will be contributing significantly to the environmental degradation in your area. This will be felt mainly by your neighbours, whose windows will be filled with smoke.
Perhaps we send smoke into the air whenever we heat with wood. Don't we?
Unfortunately, this is a widespread misconception. If you operate a wood heater properly, the neighbors don't know you're heating. You don't smoke from the chimney. Or rather, it only smokes a little for a few minutes after the fire is lit, before the temperature in the fireplace rises sufficiently. After that, nothing.
Do you think you can go wrong with an ordinary fireplace?
Yikes. Even though fireplaces are the simplest of stove constructions, a lot can go wrong with them. As I mentioned earlier. The trio of power, air, chimney is essential. Especially in today's new buildings, which have minimal heat loss and are completely tight. If the air supply is underestimated, the fireplace will smoke. The combustion gases from imperfectly burning wood are toxic, so there is a risk of poisoning yourself in such a case. However, the biggest mistakes made today are in the choice of glass size. A good portion of the heat generated in the fireplace passes through the glass. And if your living room is unable to absorb this heat, it will be uninhabitable. It will be overheated. This will lead the user to try to heat with less wood than the fireplace is rated for, which will lead to imperfect combustion, blackening of the glass and a potential risk of indoor air contamination.
And do you have any patterns for all this?
Sure. For this, and a lot of other things around fireplaces, stoves and cookers. We're playing with fire. And fire, as we know, is a good servant but a bad master. That's why we should be humble before it and understand how to work with it as best we can.
How or what should I ask the stove builder so that I don't fall for a non-expert?
Well, the stove man should ask you first. He should do a pretty deep analysis of what you want from your future heater. Regardless of whether it's a factory-built stove or a custom-built heater, he should be interested in how you will use the property where the heater will be installed. Will you be living there permanently, or will you only be going there on weekends. What materials the house is built of, what windows and doors it has, how it is insulated. Where and where will you bring the wood from? Do you even have enough space to store the wood? Where in the room will the heater be placed. Does the floor have sufficient load-bearing capacity? Do you even have a chimney? And what are its parameters?....
On the other hand, you should ask whether the stove builder offers you certified products, i.e. components, including fireplace inserts, which are developed and directly intended for incorporation into stove building.
Furthermore, you might or should be interested in whether your stove supplier has the appropriate education in the field. Whether he is an apprentice or has undergone retraining. What experience he has and whether he keeps his training up to date.
Anyone with a trade licence should have the relevant education. Shouldn't it?
You will be surprised, but unfortunately, a trade certificate for a stonemason can nowadays be obtained by a bricklayer, because it is a related trade. Nothing against honest bricklayers, but masonry is a very demanding trade today. The occupation of a mason is roughly the same as that of a bricklayer in 5%, but this does not prevent the officials at the Ministry from stating that it is fine in this way. There are just over two thousand trade licenses issued for the trade of mason in this country. There are just over two hundred companies in a single trade organisation, the Guild of Stove Makers of the Czech Republic. For the others, it is with a big question mark whether they have adequate education.
