Frequently asked questions

If you have a question about one of our products, or the use of the products, you can find more questions in the categories to the left. If you have further questions that are not present on this page, you are welcome to contact us by phone: +45 97 37 60 33 or by e-mail:

In general

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If you go to our menu and choose products, you will our entire selection of products. Then you can add items to the shopping bag and move on to checkout. We are ready tp help you in our opening hours if needed. 

We do not deduct money until we have shipped your items from our warehouse. We ship the items within 1-3 days, but you will of course be notified when your items are on their way. 

Yes, all our prices are included VAT unless anything else is indicated.

The shipping cost depends on how you want your items delivered. We offer free pick-up at our address, but you can also choose pick-up at your nearest parcel shop or delivery directly to you or your place of work. Our shipping cost starts at 39 dkk. 

Yes, you can choose as a shipping method that you will pick-up your items at our address. Your items will always be ready the day after ordering (not counting weekends). If you order during the weekend, your order will be ready for pick-up the following Monday (after 8:30), and there is of course no shipping cost.  

Flagstone treatment

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No. The Bollerup Jensen Impregnation product is a very eco-friendly solution based on natural materials (See no. 6). It is, however, necessary to be aware of the products high pH and the product needs to be disposed of in a proper manner and not be held down the drain. If you use the recommended amount of the product, it will not be harmful for the environment. There is no toxic fumes connected to the use of the product.  

When you apply Bollerup Jensen Flagstone impregnation product which is based on liquid silicates, this will penetrate down into the concrete and bind all loose particles that otherwise will react with water and then be washed of the flagstone. This treatment will leave the flagstone strengthened surface that is more resistant to wear and tear. The treatment will also leave the flagstones open to diffusion which means that rain water can seep through the flagstones. Contrary to other impregnation products which closes the surface, Bollerup Jensen impregnation product will less of a tendency to form puddles after rain and slippery surfaces in winter time. 

Internal testing has shown that Bollerup Jensen impregnation product for flagstones will have a closing effect that will make it easy to remove coatings of algae and moss after a few months. You will get the nicest result by cleaning the flagstones thoroughly and thereafter treat them with Bollerup Jensen impregnation product (see no. 2).

Yes and no. An algae remover will be more efficient at a short term basis. However, most algae removers found on the market are extremely toxic. They are strainous to water treatment systems and to our environment. Algae removers will not strengthen the flagstone or hinder new algae growth, when the product is washed off. Bollerup Jensen Flagstone Impregnation product will be more efficient long term. It is not toxic and it will not burde the environment or the waterworks. If used correctly, Bollerup Jensen Flagstone Impregnation product will hinder growth of coatings on flagstones and concrete. 

The product is not suitable to be used on plants, but it is our experience that the impregnation product does not apply any harm if by mistake a small amount should reach the plants. However, we recommend to be extra careful around acid soil plants as the product is very alcalic and therefore carm harm this type of plant. 

The flagstones will not change color, but the first month or two it can have a more wet and dark “look”. This will disappear again and the only difference you will notice is that the coatings will have worse terms to attach to the flagstones. 

If you use a patio-cleaner or use your pressure cleaner in a gentle manner with an angle of 30 degrees, the damages will be minimal. What happens when you clean the flagstones is that ingrained organisms along with the natural wear and tear through daily use and salt in the winter time is removed effectively and leaves the flagstones clean. However, it also leaves the flagstones more open and receptable to new coatings. 

The works of an impregnation depends on the conditions that the flagstones have. A patio that is not used during the winter will have less wear and tear than a driveway or road that is used daily. A test of wear and tear done at a lab in England has shown that a treated surface will have a greater duration. Surfaces that is treated with product with a low pH (acid) will demand more frequent treatments than if treated with Bollerup Jensen Flagstone Impregnation product as acid will attack both the concrete and Bollerup Jensen Impregnation product. 

At this time we do not have enough experience with the use of our impregnation product on brick walls and we can, therefore, not recommend this. Bollerup Jensen Flagstone Impregnation product is developed for the treatment of concrete surfaces as well as products containing a great amount of concrete for example flagstone. The use of our impregnation product on brick walls is therefore on your own liability. 

We, furthermore, do not recommend the use of the product on rooftops as we have not tested the product for that type of use. The use of the product on the roof is therefore also on your own liability. 

Yes. The areas that are being treated with the product have to be completely dry and clean in order to obtain a good result. You always have to cover windows, doors, and frames so the impregnation product is not in contact with anything else than your flagstones. In case, the product does come in contact with anything else, you have to rinse the area with warm water. If the impregnation product comes in contact with glass or aluminium surfaces a chemical reaction will occur and will be close to impossible to remove the stains. Make sure you also remove all garden furniture, flower pots and other items from the area before starting the treatment. 

Do not use algae removing products with Benzopotassiumhydrochloride in areas that you want to treat as that will evoke white stains on the area when it is mixed with the impregnation. Protect your skin and your eyes when applying the product and never ingest the product. 

As the impregnation product can easily be confounded with clean water, you used never leave it with easy access for children to come in contact with it. Bollerup Jensen Flagstone Impregnation product reacts with lime and other chemicals and it is therefore of great importance that the equipment used for the treatment has been cleaned throughly before used. 

The puddles will hinder the product in reacting with the concrete and there can be formed white stains of the surplus impregnation product when the flagstones are dry. 

As the product in its concentrated form is a very thick liquid, it cannot be used directly as the product will not penetrate the flagstones and it will not have the desired effect. If the product is diluted too much, there will not be enough active matter in the dilution for the product to work properly. We always recommend that the product is diluted as indicated on the label. 

We recommend that you impregnate the flagstones after they have been cleaned and before adding joint sand. The advantage of this is that there is no sand on the surface of the flagstones to hinder the impregnation in coming into contact with the concrete. If you wish to impregnate the flagstones after adding joint sand, it is important to sweep the flagstones clean of sand before adding the impregnation product. 

It is important the surface of the flagstones are clean and it is possible for the impregnation product to penetrate down through the flagstones in order to get the best possible result. If there is leaves, plants, dirt, rocks or something else on the flagstones that will hinder the impregnation product in penetrating the flagstones, you will not get the desired effect. It is important to clean the flagstones beforehand either by using a Patio cleaner or a pressure cleaner. 

Liquid silicates

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Yes, you can find liquid silicates in our webshop. If you have any questions, you can call us at +45 97 37 60 33.