How to Install Styrofoam

Styrofoam insulation is light and easy to work with.

Styrofoam has been in use as a building material since the 1960s and for good reason. It is light and easy to cut. An insulator and moisture barrier, Styrofoam is produced with locking edges that automatically create a solid joint. No further taping or joint attention is necessary. It is available in 4- by 8-foot boards with thicknesses of 1 1/2 inches or 2 inches . This building material can also stand up to pressure cleaning that will help it retain its new appearance.

Things You'll Need

• Hammer
• Nails with washers
• Rolls of insulation tape
• Spatula
• Straight edge
• Tape measure
• Utility knife
• Scissors

Instructions

1. Use a tape measure for the piece needed. Use a straight edge and a utility knife to score the Styrofoam to fit the desired coverage area. You may just use a pocket knife to score the material and then break it over a straight edge. (If you do score and break it, score it deeply enough for a clean break. Be sure to apply firm, even pressure to both sides as you break it over your straight edge.)

2. 

   Stud coverage is key.

   Install the cut Styrofoam in an upright position. Make sure your piece of Styrofoam is wide enough to cover at least three or more studs in your wall. Your Styrofoam joint edge must sit midway onto the stud to which you are attaching it. (The edge of the board should rest on the midpoint of the stud.) It is a good idea to have as few Styrofoam joints as possible create a solid insulation and moisture barrier.

3. Drive your fasteners at least 1 inch into the stud to which you are attaching the Styrofoam. Remember to use rust-resistant fasteners with washers. Because this material is so light, you must have a solid attachment. Otherwise, the result can be vibration and breakage, so do not fail to use fasteners and washers on every stud. (If your studs are metal, be sure to use an appropriate washer.)

4. Lock the lapped edges as you install the panels. This is key to creating a seamless, solid wall of insulation and moisture barrier. End-joint gaps should be filled with spray foam sealant to maintain insulation integrity along your wall.

5. Seal all Styrofoam joints with Styrofoam tape for added weather protection. Use a putty knife or other similar flat edge to smooth the tape as you roll it onto the joints. Be sure to flatten out all bubbles under your tape. Styrofoam tape will not tear evenly. Always use construction scissors or a knife to cut the tape evenly, overlapping your ends by 2 to 4 inches.

Tips & Warnings

• Be sure to use only Styrofoam-suitable fasteners, tape and insulation foam with Styrofoam products.

• Bigger peaces can break if you are working in strong wind or without careful handling.

• Leave no gaps, no matter how small. Each gap is a leak.

References

• Dow Chemical Co.: Interior Basement Wall -- Installing Styrofoam Wallmate Insulation

Resources

• Read this Article in Spanish
• Owens Corning: Residential Insulation for Homeowners and Professionals