What Is MEPS Foam Board?

  • Beginner

What is MEPS? Well, for starters, foam board insulation is rigid foam in sheet format. It is a very stiff panel that is used to insulate the entire length of a building. This is used for various construction purposes. It can be placed on ceilings, walls, and floors. This material is also often used for insulating the inner panels within a concrete building structure.


One chemical composition of foam board insulation is MEPS. This is an acronym for molded expanded polystyrene. Also referred to as beadboard, this kind of insulation is created from the mixture of unexpanded polystyrene pellets and beads that have pentane. This blend is then heated. The heat makes the beads expand. Afterward, the expanded bead mixture is placed onto a mold, further heated, and formed into foam blocks. The foam is also sometimes left in the beaded form.

When you look at MEPS foam, you will find that it looks like the same material that coolers and disposable coffee cups are made from. The usual R-value of this material is between 3.8 and 4.4 per inch. It is also the cheapest kind of foam board insulation available in the market.

MEPS foam is very easy to put up but it does wear out much faster. This is because it can easily absorb water vapor so it has a greater tendency to get warped.

The physical characteristics of beadboard will depend on the kind of beads that were put into making it. It also depends on the density that it is manufactured in. The density needed is determined based on what it will be used for. If the foam will be used for roofing, it has to be denser since it should be weatherproof and solid enough to protect the structure beneath it. The beadboards used for simple foam insulation don’t have to be as dense as the latter type.

Safety Precautions

You can select the facings of your foam board. Remember that it is easy for this kind of foam to absorb water so you might want to try putting a vapor diffusion retarder on the beadboard.

Just like other kinds of insulation, this foam board is hard to ignite but once it is alight, the fire will spread really fast and even emit smoke that contains harmful chemicals. Most users would have gypsum wallboard covering it as a way to prevent fire. When using this material as part of a building structure, you will need to find out what the specifications are in the local building codes.

Another problem that you might arise with using MEPS beadboard insulation, aside from water absorption and fire, is insects. These critters will not eat the board but they will try to get through it. When this happens, the R-value decreases. This is why most makers of foam boards will include insecticides on their products.

Also, it’s important to be aware of the static electricity that the beadboard can emit. This is due to the material being very lightweight. This characteristic also makes it hard to control the wind effect on the foam. If they are left in the aforementioned bead format, the rush of air when there is an opening exposing it will break it down sending the beads spilling out.