How to Tell If My Siding Is Synthetic Stucco

Synthetic stucco, also known as "exterior insulation and finishing system" or EIFS, has been used since the 1950s as a highly efficient, waterproof exterior finish that has the appearance of cement stucco.

Is it real or synthetic?Is it real or synthetic?
The advantage of synthetic stucco is that houses covered in insulating synthetic stucco can be heated and cooled with less output. The disadvantage is that if the seals around synthetic stucco are compromised, moisture can get in but it can't get out, which can lead to rotting wood and other issues.

Look closely at the surface of the stucco. If there are cracks, it's likely that you have cement stucco, not synthetic. If there is any wire mesh visible under the cracks, it is most likely cement.

Spray a little water on the surface of the stucco. Synthetic stucco is waterproof, and will not absorb the liquid. Cement stucco will absorb it, then dry.

Tap on the surface of the stucco gently. If it has a hollow sound, it is likely synthetic stucco. If the sound is solid, it's cement.

Tips

  • If you still can't tell whether your stucco is real or synthetic, have a home inspector check it.
  • If your home was built before 1980 and the exterior hasn't had a major renovation, your stucco is real; however, many newer homes also have real stucco, so a newer home doesn't automatically indicate synthetic stucco.

Warning

  • Synthetic stucco with broken seals on joints around windows and punctures in the surface can lead to serious damage to your home. If you see any problems, have them fixed by a professional as soon as possible.

About the Author

Delaware-based Daisy Cuinn has been writing professionally since 1997, when she became the features editor for her local biweekly music newspaper. She has been a staff writer and contributor to online and offline magazines, including "What It Is!," Celebrations.com and Slashfood. Cuinn holds a Bachelor of Fine Arts from Temple University.