Dryvit

[Vernon Martin]

So many commercial properties have Dryvit cladding now, but what is it actually made of?
It seems too soft to be sheetrock or Hardi-board, too hard to be styrofoam.

 

[Mr Rex]

Dryvit is synthetic stucco. Usually a foam sheet backing over some type of sheathing, with various grades of fiberglass mat over the foam, depending on how much puncture resistance they need. Tougher at ground level, softer at inaccessible areas. The actual coating is an elastomeric (non-breathable, with elastic properties) type coating with sand or other aggregate mixed in to give it the stucco look. Its the same stuff that has been the subject of class action suits in residential construction, because of improper installation and lax supervision and detailing in residential vs commercial.

 

[Vernon Martin]

Great answer, Mr. Rex. Thank you.

 

[The Warrior Monk]

We don't see much dryvit on commercial buildings; hardiplank is very popular these days. It is still used on residential buildings; supposedly improvements have been made over the years to let it breathe.

 

[Mr Rex]

Hardiplank had a problem with breathing?

 

[3 Putt]

If properly installed it's a great product. You can have some very creative designs, etc. Long lasting, quite durable. Most of the problems have come from improper installation. The product got very popular and in high demand. Then everybody became a dryvit expert and started installing it.

Gee...sounds like appraising...can you say "skippy"

 

[Charles Knutson]

Dryvit is synthetic stucco. Usually a foam sheet backing over some type of sheathing, with various grades of fiberglass mat over the foam, depending on how much puncture resistance they need. Tougher at ground level, softer at inaccessible areas. The actual coating is an elastomeric (non-breathable, with elastic properties) type coating with sand or other aggregate mixed in to give it the stucco look. Its the same stuff that has been the subject of class action suits in residential construction, because of improper installation and lax supervision and detailing in residential vs commercial.

The problem with synthetic stucco systems is that they sometimes create a vapor barrier on the exterior of a structure -- which leads to moisture being trapped between the inner vapor barrier and the exterior cladding, which can then become an ideal growth medium for microbial and fungal organisms.

In the mid 90's, one of the Carolinas banned synthetic stuccos -- they found that moisture could even enter the wall through wood window sills, one of many ways the system could be compromised.

If synthetic stuccos are installed with vapor relief channels behind the styrofoam substrate, they will vent off moisture in the same way conventional construction breathes. But most of the installations in the 1990s were styrofoam glued onto exterior sheathing -- which means that the system is only as good as it's overall prevention of moisture entering the structure.

In Colorado, most builders have gone back to using traditional stucco, which is a sand and cement plaster -- which is permeable to water vapor, and thus avoids the potential problems of faulty synthetic stucco installation.

 

[The Warrior Monk]

Hardiplank had a problem with breathing?

I can never tell when your busting my chops...

Improvements supposedly have been made to dryvit.

 

[Mike Boyd]

We don't see much dryvit on commercial buildings; hardiplank is very popular these days. It is still used on residential buildings; supposedly improvements have been made over the years to let it breathe.

Drivit and hardiplank are altogether different products for different uses. My experience with Drivit is that it is designed to be covered with a different, more durable finish. Drivit may even be overlayed with Hardiplank. Of course, products change and maybe nowadays Drivit is available with a finish considered to be durable.

 

[Joker]

The material you are discussing is Exterior Insulation Finishing System (EIFS). Dryvit is a brand name. Be careful not to use that name unless you are certain that it is in fact Dryvit.

More information about EIFS can be found here
http://en.wikipedia.org/wiki/Exterior_Insulation_Finishing_System

HardiePlank is a brand name of cement fiber siding made by James Hardie. There are other brands.

Just as you shouldn't call all jetted tubs "Jacuzzi", you shouldn't call all EIFS "Dryvit" and all fiber cement siding "HardiePlank."