Doing it yourself or calling a specialist

What you can do yourself

• Treating contact surfaces after illness in the household.
• A small, freshly appeared mould patch on a smooth surface — tile, a window frame, a painted wall with the paint layer intact.
• Everyday cleaning and disinfection of surfaces in the kitchen and bathroom.
• “Reviving” dried-out traps — simply pouring water into a rarely used floor drain or shower.
• Sorting out your airing routine, which is the main form of mould prevention.
• Washing textiles at a high temperature.
• Cleaning the fridge, the washing machine seal and the dishwasher filter, which are a frequent source of household smells.

If your situation is on that list, you do not need a specialist, and we say so on the phone too. Nobody needs a call-out that ends with the advice to pour water into a trap.

How to do it properly

Most DIY treatments fail not because the product is weak but because one of the steps is skipped. The practical sequence for a small patch looks like this.

• Air the room and put on gloves; if the patch is large or dusty, a face mask too.
• Clean the surface mechanically with detergent — not with a dry brush, which throws spores into the air.
• Wipe off the excess water; a wet surface dilutes the product and lowers the concentration.
• Apply the product at the correct concentration according to the label, not by eye.
• Let it stand for the stated contact time — this is the step that gets skipped most often.
• Air the room and check a couple of days later whether the patch has come back.

If the patch is still in the same place two weeks later, the treatment has not failed — the problem simply is not on the surface. The question is then about damp, and that is dealt with differently: see humidity control and ventilation.

What you cannot do yourself

• Treat what you cannot reach — ventilation ducts, gaps, the filling of soft furniture, the space behind fitted structures.
• Establish the cause of damp — without instruments that is a guess, and a wrong guess costs more than an inspection.
• Remove a smell that has soaked into materials — that is a question of equipment, not of the product.
• Treat large areas — by hand that is not realistic; fogging is needed.
• Work with waste-water contamination — that involves both safety and an assessment of the materials.
• Dry out a structure after flooding — a fan and an open window are not the same as a condensing dryer with readings.
• Judge what has to be removed — which piece of plasterboard can be saved and which cannot, which board will return to shape and which will not.

The line is not about how strong the product is. It is about whether you can reach the whole problem and whether you know its cause.

Why there is a difference

Importantly, the difference is usually not that professionals have “stronger chemicals”. The difference is equipment that reaches what a hand cannot, and readings that show the cause. A fogger breaks the product into droplets fine enough to settle on every surface, including ceilings and the insides of gaps. Ozone is a gas and gets where no cloth can. A moisture meter says where the water in a structure is and how deep it goes.

There is another side to this that is only fair to state: for a small patch in a kitchen we cannot do anything better than you can with a cloth and five minutes. The advantage of equipment only appears when the task exceeds what can be done by hand.

About shop-bought products

Shop-bought disinfectants are perfectly normal products that do what they are made for — treat surfaces. They only fail to do anything when:

• they are used on a dirty surface;
• they are wiped off before the contact time is up;
• they are used against a problem that is inside a material;
• they are used as a substitute for dealing with the cause;
• they are diluted stronger or weaker than the label says.

On home remedies separately. Vinegar, bicarbonate of soda and citric acid are useful for cleaning — they dissolve limescale and grease. But against fungus that has already grown into a porous material they do not work, and there is no point expecting them to act as a disinfectant. More importantly: different products must never be mixed. More on that on the page about the products we use.

Three questions to place the line

If you are not sure which side of the line your situation is on, answer three questions. If the answer to all three is yes, you do not need a specialist.

More on mould products and what actually works: can you remove mould yourself.

Three concrete cases

Abstract criteria are useful, but in practice the line only becomes clear in specific examples. These three are our most typical calls, and in only one of them is the answer “call us out”.

The first: bathroom grout — do it yourself

Black deposit in bathroom grout and in the silicone seal around the bath. Small area, hard surface, obvious cause — the room does not have time to dry out after a shower. No specialist is needed here. Clean it mechanically, treat it with a product made for the job, and above all sort out the ventilation and the gap under the door. If the silicone is black all the way through, replacing it is easier than treating it; that is an hour's work.

The second: a bedroom corner — borderline

A 0.3 m² patch in the external-wall corner of a bedroom in a Soviet-era panel block, appearing in November, behind a wardrobe. Treating the surface yourself is possible, but the question is not the patch — it is whether the damp is only condensation or whether the panel joint is letting water in from outside.

If, after treatment and moving the wardrobe, the patch does not come back next season, you were right. If it does come back, a measurement is needed, and at that point we are cheaper than a third round of treatment.

• The first case — your job: hard surface, small area, known cause.
• The second case — borderline: treatment is possible, but the cause is not yet proven.
• The third case — a measurement is essential: the damp is in the structure, not on the surface.

The third. Flooding from the flat above, water having run across the ceiling and down the wall, laminate swollen, and a basement smell appearing a week later. There is nothing to be done yourself here. The problem is in the structure rather than on the surface: the damp is under the floor covering and possibly in the floor slab, and without readings there is no telling how far it extends. A fan and an open window will not dry this out, and treatment before drying is wasted.

The common principle in all three is the same: if the problem is on the surface and the cause is known, it is yours. If it is inside a material, or the cause is unknown, it is a question for measurement. The price for that is known in advance — an inspection with moisture readings from €40, and we deduct that amount from the price of the work if we then carry out the treatment.