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How to build a waterproof cat house | 7 simple steps

If you want your cat to be safe and warm when it’s raining outside, make sure your pet has a nice and comfortable waterproof cat shelter to go to. Of course, the best solution is to keep your cat inside when it’s raining or snowing, but if your pet likes to roam freely outside, then building a waterproof cat house is a very good idea.

If you haven’t done this before, I got you covered. I recently built a cat shelter for one of my friends and I’ll list all the steps to follow in this guide.

What you need for building a waterproof cat house

  1. A large plastic storage container with lid.
  2. A smaller plastic storage container with lid. Make sure the second one is small enough so as to be placed inside the large plastic container.
  3. A sheet of foam board insulation or polyurethane foam sheets (I used polyurethane foam).
  4. Duct tape.
  5. A pair of scissors capable of cutting through the plastic or a utility knife.
  6. A pile of straw or an old blanket (optional).

Steps to build a waterproof outdoor cat shelter

Step 1: Cut a hole in both containers

This will be the door for your cat shelter. You don’t want this to be a large hole, just cut it large enough for the cat to get inside but small enough to keep other animals at bay.

Step 2: Tap the edges with duct tape

You can now use the duct tape to cover the rough edges of the entry. If you keep the rough edges, your cat might bruise its skin when in a hurry to get inside.

Step 3:  Use foam sheets to isolated the containers

Now it’s time to place a foam sheet on the bottom of the big container. You can now place the smaller plastic container in the large one. Once you’ve checked the two entry holes are aligned, you can put a layer of insulating foam between the two containers. Cut through the insulation foam where the door of the shelter is.

Additionally, you can also use some expanding foam between the two containers for extra insulation. But that’s optional, I didn’t have a can of expanding foam at hand, so I used polyurethane foam only.

⇒ Learn more: How to waterproof a dog house | Step-by-step guide

Step 4: Place the lids on the small container

Now that you’ve insulated the space between the two containers, you can put the lid on the small container.

Step 5: Place polyurethane foam between the two lids

Once you’ve closed the lid of the small container, you can now place a polyurethane foam sheet between the lid of the small container and the lid of the large container. Once again, using expanding foam is optional.

Step 6: Place some pieces of cloth in the small container

To help your cat feel as warm and comfortable as possible, place some pieces of cloth in the container. You can also threw in a few handfuls of straw over the floor of the cat house. Then, placed an old wool blanked on the straw bedding. This will keep your cat warm when it’s cold outside.

Step 7: Secure the shelter in place

Make sure strong gusts of wind cannot overturn the cat house. Lay a few bricks on the cat shelter to weigh it down.


To build a waterproof cat house, take a large plastic storage container and cut a hole in it. That will be the door.
Then use foam sheets to isolated the container. Place some pieces of cloth inside the container to keep your cat warm. This is how you can build a nice waterproof cat house on a budget to keep you pet safe. 

Last updated in October 2021 to add additional information.

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