We usually say that you should think of the PORTAL shelf almost like lego. You can build it up and extend it as you like. Very flexible!

Though – there are some things that need to be considered when planning:


Our longest shelf is 201 cm. If you choose shelves in pinewood or MDF you can extend the shelves using a shelf extender to make the shelf as wide as you like. Read more about it below. Email us on hej@betonggruvan.se if you’ve got questions.




If you use the shelf extender there are some things you must consider. Like this:

  • The shelf extender CAN be used if you want a shelf wider than 201 cm, but you don’t HAVE TO use one. You can also combine shelves in a way that leaves air in some parts to avoid the shelf extender.
  • The shelf extender is used for connecting two shelves on the underside, see picture above.
  • The shelf extender should always be centered on a shelf ladder, see picture above.
  • When two shelves are connected with a shelf extender they “share” one shelf ladder. This makes the system broaden with 2 cm.
  • On the ladder where the shelf extender is placed, you should not pay attention to the holes in the ladder or the metal fasteners. They are NOT fitted for the shelf extender. You get 4 small screws with your extender, to fasten the extender to the shelf. (no holes are predrilled) The shelf extender should just rest on the shelf ladder, centered.
  • If you use a shelf extender, make sure to always connect the extenders and the shelves to see the full width of the shelf, before you mount the shelf ladders to your wall, to make sure you get the right width.
  • If you’ve chosen a complex version of the PORTAL shelf (See scenario 2 below) and your shelves will protrude somewhere you can choose to cut the shelves yourself (only if you have pinewood shelves)




There are two scenarios for when the shelf extender is needed.

Let us sort it out:

Scenario 1: Shelf with parallell shelves in the same width. (for example 123+123 cm wide)

If you have the same width on your shelves throughout the shelving system you shelf will not be affected when using the shelf extender. Your shelf will be 2 cm wider since two shelves are sharing one ladder.

PLEASE NOTE: It is always best to connect the shelves before mounting your shelf ladders on the wall. This way you’ll see the total width of the shelves and can adjust the ladders to fit perfect.




Scenario 2: Shelf with mixed shelves  / different widths on the shelves.

If you want a more complex/bigger shelf and want it wider than 158 cm you can use the shelf extender. To use it when having different widths throughout the system can do that some shelves will protrude from the ladder with one centimeters. See example below. If you want every shelf to be in line with the shelf ladders you can use pinewood shelves in those cases and cut them yourself 1 cm where the situation occurs.



If you have more questions regarding the shelf extender we’d love to help. We are also here to help you design and draw the perfect shelving system for you wall! Don’t be shy!

Please contact us on hej@betonggruvan.se