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Are you an individual? Find our frequently asked questions and contact information

Answers to your questions

In this section, you’ll find our frequently asked questions. If you have any other questions which we have not answered, please take a look at the information below for where to send your queries, depending upon which country you live in:

    France - by mail only. Clearly indicate your full name, address, telephone, email the precise subject of your request to Grosfillex - customer service - rue de Lac - 01100 Arbent
    Germany - by email at
    England - by email at
    Spain - by email at
    Holland - by email at
    Italy - by email at
    Switzerland - by email at
    Austria - par mail à
    Belgium - par mail à
    Luxemburg - par mail à
    Portugal - par mail à


Do you need to get in touch with customer services, or do you need parts for a purchase you’ve made in a food retailer, DIY or gardening outlet?

Apart from the factory store and the products marketed in the Grosfillex Fenêtres dealer network, the Grosfillex company does not sell directly to consumers. This is why you need to make any enquiries at the point of sale where you made your purchase of Grosfillex products.

Find the answer to the questions that are most frequently asked by Grosfillex consumers, organised per product line.



FAQs – Garden shed

Question 1: do I need permission from the local authorities to put up a garden shed?
Answer 1: we recommend that as a matter of course, you get in touch with your local authority or council to obtain all the relevant information before your purchase your shed.

Question 2: do I need to insure my shed?
Answer 2: we recommend that you contact your insurance provider. An amendment to your housing contract may be necessary.

Question 3: what materials are Grosfillex sheds made from?
Answer 3: they are essentially made from PVC (resin). Some components are made of polypropylene. The frame is metal and treated against corrosion.

Question 4: what is the slope of the roof and its colour?
Answer 4: the slope of the roof is 20°/36%. Its colour is grey-green. We really don’t recommend you cover it with bitumen sheets or dark paint.

Question 5: do I need to put in foundations before I install my shed?
Answer 5: It’s best to assemble the shed on a perfectly flat floor, and never directly on the ground or the lawn.
Small sheds (up to 4.9 m2) can be built and set on gravel or with concrete corner supports. For sheds larger than 4.9m2, we systematically recommend that you put in a concrete slab (foundation), on which you should build your shed.
The concrete slab must be 10cm in thickness and 3 to 5cm around the outside of the shed. Whatever the size, we recommend you strengthen fixing the shed on its base using a Grosfillex anchoring kit. Please refer to the accessory form in the anchoring kit for more information (available in shed product sheets).

Question 6: How will be my package be packed  when I receive it?
Answer 6: your shed is packed on a pallet in a vertical position. For shelters of 19.6 m2, it takes 3 pallets. The elements of your shelter should be stored flat before putting it up.

Question 7: How do I assemble my shed?
Answer 7: Before putting up your shed, do a complete inventory using the nomenclature on the installation instructions. Do not attempt to assemble it if any parts are missing or damaged.
Putting it up is simple. To get an idea about the installation, you can watch the film on our site, which clearly sets out how to install it. Installation requires 2 people and will take 1 day. Installation should be carried out in one day where possible (3 people for sheds measuring 19.6 m2). Do not assemble the shed on very windy or very cold days. The tools required are: a stepladder, a metre rule, a drill, a screwdriver, gloves and goggles, a spirit level, Ø6 et 10 mm drill bits, a spanner, and a Phillips screwdriver.

Question 8: My shed is leaking water, what do I do?
Answer 8: Check that the slates are completely fitted together and reinforce the seal with silicone as explained in the instructions that you can download from our website  under the ‘sheds and storage’ section.

Question 9: My shed has condensation at the windows, what should I do?
Answer 9: Condensation is due to thermal differences between the external environment and the interior of the cabin, and it is the result of the excellent insulation qualities of the PVC material that in some climates you’ll get this condensation. To remedy this, increase ventilation by adding a ventilation grill to the upper outer part of the shed.

For all other questions, please refer to the “sheds" product sheets that also include the assembly instructions and product sheets for each shed and accessory.

FAQs – garden furniture

Question 1: How do I clean my outdoor garden furniture?
Answer 1: for cleaning garden furniture that is made of resin, Grosfillex advises suitable cleaners sold in DIY and gardening hypermarkets and stores

FAQs – wall cladding

Question 1: Where can I find finishing profiles and accessories to help with installation?
Answer 1: These products are sold in DIY superstores and by dealers of building materials.

Question 2: On what surfaces can you install PVC Grosfillex cladding?
Answer 2: The surface material must be level (irregularities of a maximum of 2mm), clean and dry.  Most materials can be used: wallpaper, earthenware slates, painted or coated walls, panelled walls. On a wall or ceiling that’s irregular or damaged, we recommend that you install the cladding on battens.

Question 3 - How do you fix PVC Grosfillex cladding to a wall?
Answer 3: It’s possible to install them by gluing, nailing, screwing or stapling. The gluing installation method is the method preferred by many installers for its efficiency and its speed of implementation.  The surface must be flat, dry and clean. This method is one of the better ones for minimising the use of material and achieving a very accurate rendering. Installation is possible by gluing directly on the material to be redecorated or using Exapan double-sided tape, Grosfillex Gx Power glue, or an equivalent PVC adhesive.

The nailing method is when nails are uniformly applied along the level of the tongue on the slate. This method can be used when the installation is carried out on wooden battens. Make sure that the batten is flat and horizontal, and where the cladding needs to be used on uneven walls, attach the battens so that there is no curvature and they follow the contours of the walls. If walls are wet and uneven, it is recommended to use treated wood. Be sure to leave adequate ventilation behind the external cladding, leaving space between the battens.

If you use the screwing method, then apply screws to the tongue of the slates. The fixing screws can be mounted on wooden battens. However for cinder blocks, bricks, or gypsum plaster board, then wood battens must be put in place before you screw anything down.

With the stapling method, you can use stainless steel staples for fixing cladding on plasterboard and wooden partitions. This method is particularly useful when you use wooden battens. Make sure that the battens are flat and horizontal, and where the cladding is needed for use on uneven walls, attach the battens so that there is no curvature and they follow the contours of the walls. If walls are wet and uneven, it is recommended to use treated wood.

If the slates are fitted with screws or staples they must have a waterproof strip along their side. According to the condition of the material to be redecorated, they will be then stapled or screwed into battens, or directly into the wall if possible.

Question 4: How do I install my PVC Grosfillex cladding on a ceiling?
Answer 4: For ceiling installations, then the screwing in method is recommended.

Question 5: Which product should I use for a shower compartment?
Answer 5: Most Grosfillex decorative cladding can be installed in the shower. For easy installation, go for products that have a length of 2.6m or 4m with a tongue down the side, and which can be installed vertically. Horizontal installation is also possible, if the slate is equipped with a tongue on the longer side and it goes from one end to the other of the shower. Otherwise, add a silicone seal to the smaller side of the slates.

Question 6: Do I need sealant in the joints between the Grosfillex cladding slates in order to have a waterproof wall?
Answer 6: The slates themselves are completely impervious to moisture. For most of the range (slates of 2.6m and 4m long), the joined slates offer a seal when the product has a tongue down the side. In instances where the wall is exposed directly to splashing water, for example the wall of a shower, then the periphery of the walls should be treated with a silicone seal (including between the slates and the edge of the shower or bathtub). The product sheets will also give you guidance on sealing.

Question 7: How do I cut cladding slates and finishing profiles?
Answer 7: Slates can be easily cut with a cutter, or even with tools that have fine teeth. With the cutter: cut the slate flat, front side facing up, then press firmly and the top of the slate will break cleanly. Then just turn over the slate to finish the cutting on the wrong side. Finishing profiles should be cut with a fine-toothed tool or cutting pliers.

Question 8: How do you finish walls or ceilings?
Answer 8: Finishing profiles are adapted to each use: finishing and clippable finishing (for the edges), internal and external corners, as well as more specific uses. Please consult the product sheets to check the use of the different solutions. In addition, to achieve an external or internal corner, you can dimension the back of the slate and give it the desired curvature.

Question 9: Can I attach elements to the wall (decoration, shelves etc.)?
Answer 9: Yes. Once the cladding is installed, you probably need to fix other elements to the walls, like soap holders, curtain rods, a table, etc. In this case, you will need to drill the slate and the wall behind in order to hang objects. The weight of the objects will be therefore supported by the wall.

Question 10: Can I use cladding near a hot spot or a lighting point and at what temperature?
Answer 10: The slates can withstand temperatures between -20°C and +60°C. They cannot be used in saunas. It is advisable to check the temperature before using slates close to hot spots (e.g. radiators). In a room with a fireplace, do not use the slates at closer than 50 cm. Our cladding can be used to integrate spotlights (temperature lower than 60°C, maximum 50 watt bulb). Grosfillex offers spotlight-adapted rings which isolate the spot on the slate in order to avoid the slate being deformed by heat. The lamp used must comply with the regulations and should not disseminate the heat of the lamp in order to prevent deformation of the slate.

Question 11: Can I create a suspended ceiling with metal hangers?
Answer 11: In order to achieve a suspended ceiling, Grosfillex offers metal hangers so you can lower the ceiling by 15cm. They must be placed every 60cm. The hangers alone are not suitable for a "heavy" insulation (glass wool). To insulate before making the ceiling, then consider installing battens.

Question 12: How do I clean or maintain my PVC wall cladding?
Answer 12: A soft damp cloth is sufficient for cleaning. Use a soft, non-abrasive household product if necessary. If there is significant soiling (felt tip marker for example), use isopropyl alcohol.

Question 13: Is PVC Grosfillex cladding recyclable?
Answer 13: Yes, 100%. They can be taken to household waste recycling centres where there is somewhere for sorting plastic.

Question 14: What is the difference in the cost of putting down the PVC cladding and tiles?
Answer 14:  Tiles are available at all prices and in many dimensions and decorations. Nevertheless, they are much less easy and quick to install, meaning you’ll save in installation costs. It will be much easier for a novice handyman to put up the Grosfillex decorative slates than tiling. If you call a professional, you'll make savings in terms of work completed when compared to putting up tiles. A large selection of "tiling" products are offered in various Grosfillex ranges.

Question 15: What are the advantages of PVC Grosfillex cladding compared to the other panelling (wood etc.)?
Answer 15: The main advantage of the Grosfillex decorative slates is their resistance in a humid environment. Wood can warp, swell, or wave. Grosfillex decorative slates don’t react at all to this type of humid environment. Their resistance to fire is greater than wood panelling or coated panels (MDF etc.).

Question 16: What is the layout?
Answer 16: The layout consists of a set of drawings with instructions that will guide and plan the laying of the slates, veneer, and coverings. The layout will determine the number, location and order of the slates.

Question 17: What is a chamfer?
Answer 17: The chamfer (or face of the groove) is the small surface formed by a ridged edge. This flat surface is often the result of the edge of a piece of stone, wood or metal. The chamfer between two adjacent sides at right angles, is normally 45°.

Question 18: What is a square edge or joined appearance?
Answer 18: The side of the slate has no chamfer. When you put 2 slates side by side, it all appears smooth.