Price: $21.99

The Coroplast extension piece is to ASSIST you with your DIY (Do It Yourself) expansion of your existing CAGETOPIA C&C Cage. This can be a more cost effective way of expanding your cage instead of buying a new, full-size 2x4 Coro base. We also assume you are using Cagetopia Grids for proper compatibility.

We do not guarantee perfect fits. Pieces must be taped together (we do not provide the tape). We recommend using 2" clear packing tape on both sides of the Coroplast.

This item is NOT RETURNABLE!

Instructions for expanding are noted here online and are NOT sent along with this item. Please review them before you purchase.

You will be cutting the zip ties used to overlap the Medium grids and adding connectors in their place, in addition to the 1-grid expansion from there.

Please note! Due to the change-over to a new production supplier and new colors and printed colors, IF you ordered a cage prior to May 1 2023, it likely will not match in color. Even after May 1, we've been making various color adjustments. If you are OCD about a perfect match, we suggest replacing the base as you'll be happier. If it's for the pigs and fussiness isn't a priority, this will be fine.

Availability: In Stock


The EXTENSION piece has 3 sides with 6” walls and one end with no wall, cut to the right dimension to get to the new, desired size. Along with the additional grids and connectors unless you opt out of them.

Going FROM a MEDIUM Cage:

  • Coroplast Interior: 27" x 50" with 6" walls
  • Exterior: 2x3.5 GRIDS with overlapped grids (30" x 54")

Going TO an LARGE Cage:

  • Coroplast Interior: 27" x 56" with 6" walls
  • Exterior: 2x4 GRIDS (30" x 60")

Coro Height

We ONLY offer the extensions for 6" walls (not 12" high back walls nor 10" walls for hedgehogs).


We do NOT include the extra items needed for a cover because while you MIGHT be expanding a simple, single-level cage, it might be a different configuration altogether. IF you have a simple, single-level, covered 2x3.5 grid cage, then expanding a cover will require an additional 2 grids available here and one Wonder Bar. IF your configuration is something else, please review the What's Included tab for your current setup and what you are going to. Determine the different components needed and order accordingly. Please contact us if you need help figuring that out.


  • Our extension components are compatible with original bases, grids, and connectors purchased from us. We cannot guarantee the extensions will fit your existing base if purchased from another source or you made your own.
  • Keep in mind sizes are approximate as there can be a 1/8” – 1/4” tolerance factor (even with our bases) due to the nature of the corrugated flutes.
  • Our extension kits are made to add to the LENGTH of an existing C&C cage.
  • We do not make extensions that are compatible with creating an L-shape or expanding loft sizes. We also do not make extensions to expand greater than the standard 27” width (NO 3-GRID WIDE EXTENSIONS available from us).
  • Adding even more length than a 2x6 is possible, but you will need to measure what you need for length, and purchase the proper full-size base, starting with the 2x3.5 grid small base. Please be sure to double-check measurements.
  • Currently, our extensions are only offered in the products listed in the Cage Extensions category. If the size you want is not available, we do not offer them.


  • 4mm Coroplast bottom in your choice of 16 colors! 27" x 6" x 6" walls on 3 sides only for EXPANDING FROM a 2x3.5 (Medium) to a 2x4 (LARGE) cage. It is cut and scored on ONE END with flaps and rivets for that one end. 
  • (4) Connectors in black or white
  • (8) Snap-in Plastic Rivets to fasten flaps on one end.

OPTIONALLY, you can add in:

For expanding the cage STAND from a 2x3.5 to a 2x5:

  • (6) Connectors in black or white


  • This item is NOT RETURNABLE.
  • Instructions are NOT INCLUDED WITH DELIVERY. They are on this page on the INSTRUCTIONS tab.
  • COLOR SHADE MAY VARY SLIGHTLY. Extensions are for previously purchased coroplast cages. We do not guarantee perfect color matches within the same purchased color as production runs from the manufacturer can vary slightly in shade. We have no control over that and make no guarantees.

Extension Instructions

  1. REMOVE everything from the inside of your EXISTING CAGE base.
  2. REMOVE the Coroplast Base from your EXISTING CAGE structure.
  3. CLEAN IT WELL, especially along the end you'll be extending.
    Use a spray bottle of half water/half white vinegar.
  4. REMOVE ALL RIVETS from your existing base so that you can lay the coroplast flat. Using a butter knife or flat-head screwdriver, gently insert it between either the rivet head and the Coro or between the two pieces of Coro and gently twist until it pops out. SAVE the rivets for reassembly.


    If you want to short-cut the step of removing the rivets, you can, but if you have any issues with fit or needing trimming, having it flat will be easier. ALSO, it CAN be much easier to properly apply the packing tape in a nice, straight line with no bunching or seams when it is flat, rather than dealing with it in a box shape. Up to you.
  5. You will need to CUT ONE 6” wall OFF of YOUR EXISTING base at the scored seam where you want to connect it to the extension piece. The score already there helps make this easy. But, please try to be as even as you can with this cut. Scissors or a single-edge razor blade or box cutter will work.


    You can cut the ENTIRE 6" wall off, flaps and all OR if you want to overlap the flaps for extra strength or security, then LEAVE the FLAPS attached and only cut off the wall section on the main cage base that is 27" wide and leave the flaps alone.
  6. JOIN the seams (don’t overlap) of the extension piece to the existing base where you removed the wall. That is, butt them up next to each other as tightly and cleanly as possible.
  7. TAPE the top, sides, and underside of the base to seal it well using 2” clear packing tape (available at any home improvement center).
  8. IF you removed the rivets as in Step 4, then reinsert the rivets appropriately.

Select your Options!

Coroplast Color:
  • Green
  • Lime
  • Lemon Yellow
  • Cinnamon
  • Cool Flame
  • Raspberry
  • Pink
  • Violet
  • Blueberry
  • Navy
  • Black
  • Silver
  • White
  • Gold / P-123-81-40
  • Celery / P-195-221-156
  • Silver Mist / P-150-151-151
  • Dusty Rose / P-208-175-200
  • Periwinkle / P-146-158-212
  • Denim Blue
  • Deep Blue / P-55-50-110

More color INFO.
Printed colors "+$" carry an upcharge & need a little extra processing time.

Expand the Grid Wall:
  • Add 4 Black Connectors
  • Add 4 White Connectors
  • Not needed

When expanding the Medium Cage wall, you cut the zip-ties on overlap of the middle grids and just add the connectors to connect them normally.

Optional Cage STAND Extension Grids:
  • +2 GRIDS +6 CONN for STAND in BLACK
  • +2 GRIDS +6 CONN for STAND in WHITE
  • No thank you

Add in if you need to extend your Stand as well.

I've read the BEFORE YOU BUY tab for this item:

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