An Easy Way How to Cut Foam Insulation in Styrofoam Panels

The typical insulation sheets are made from compressed foam beads that are crafted into rectangular panels. The panels’ standard size to insulate the foundation, walls, and roof inside the house is 4 x 8 ft.

Although it may appear bulky, the material is actually lightweight enough, so it’s not really difficult to cut. Learn how to cut foam insulation below with different cutting tools for different insulation panel types.

How to Cut Foam Insulation

The type of foam cutting tools is just as many as the foam type itself. Here are five of the best foam insulation cutting tools you can easily find in local hardware stores:

how to cut foam insulation

  1. Long utility knife

A utility knife is such a versatile tool that it deserves to be the best cutting tool for foam insulation. It’s suitable to cut foam with various thickness levels. To create the best cut, point the utility knife at a 45° angle and use one smooth motion.

  1. Hot knife

If a utility knife can’t serve you a satisfying result, you may benefit from some power. A hot knife is a cutting tool that gives you both the power and flexibility to cut foam with different thicknesses.

  1. X-Acto knife

This tool has the qualities of being extremely sharp, lightweight, and easy to use. It can provide great cutting details, even on curves and dynamic shapes. However, the X-Acto knife is better to use for thinner foam panels instead of thicker ones.

  1. Hotwire cutter

Hotwire cutter has the ability to handle tough challenges such as thick foam. It is designed to effortlessly slide through the panels and create a clean result, even for the most diverse shape that you want.

  1. Cutting saw for foam

If you have many foam insulation panels to cut, using an electric cutting saw will save you so much time and hand fatigue. It is designed especially with the foot to make the serrated blade move quickly and precisely.

How to Cut Styrofoam Insulation

The most practical and effective way to cut Styrofoam panels is by using a hot wire cutter. It results in cleaner cuts. However, check first if using the hot cutting tool is recommended by the manufacturer of your foam. Some of them may contain rigid polyurethane that produces toxic fumes when exposed to heat.

Here are the steps on cut foam insulation in Styrofoam type:

  1. Use marker or charcoal to draw your desired shape on the panel.
  2. Move the hot wire cutter along with the foam with equally distributed pressure.
  3. Cut the largest sections first to provide more freedom of movement. You may need more detailed tools such as a hot knife to create fine cuts, but save them for later.
  4. The last step in cutting foam insulation is to use thick gauge wire by connecting it to the cutter to cut profile shapes, for example, if you want to angles or curves.

How to Cut Spray Foam Insulation

Spray foam insulation generates a result that mimics heavy glue or thick paint if being expanded – they stick strongly to anything. This adhesive characteristic makes the material suitable to apply to small or large areas because it sticks and expands to the desired area and creates an insulating barrier.

However, unfortunately, it is easy to misdirect the product and get it on unwanted areas such as furniture, woodwork, or walls. It is quite challenging to remove the hardened foam, but the guide on cutting foam insulation below will show you how to do it properly:

  1. Use mechanical cutting tools of your preference, such as a utility knife, to remove the hardened foam.
  2. Start by cutting as much foam surface as possible, then use a paint scraper to scrape the leftover.
  3. If possible, you may moisten the hardened foam by using acetone to make its bond loosen up.
  4. Use 120-grit sandpaper to get rid of any substrates.

The step-by-step on how to cut foam insulation is easy to follow, but prepare to ask for help from a professional if it’s your first time doing so. If you don’t feel capable of eliminating the foam insulation by yourself, professionals in this field are always ready to help you to provide high-quality and thorough work and ensure less risk of damage.

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