Stucco over concrete block
user-6514939
| Posted in General Questions on
Best practices on install of stucco over concrete block in zone 5?
Thx
Phil Ternes
Consor Development
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Phil,
The most important details you need to consider are:
(1) What type of insulation are you installing?
(2) Will the insulation be on the interior or the exterior of the wall?
(3) What type of water-resistive barrier (WRB) are you using?
(4) How is the WRB integrated with the flashing system at the window rough openings?
For many buildings, the best approach is to use EIFS. If you are going that route, the easiest approach is to hire a certified EIFS installer, who will assume the liability for water entry issues.
If you're not installing the stucco on an insulated building -- for example, if you are talking about a fence or a wall at the edge of your property line -- the work is simple, and you can follow the advice in this article: Make It Stick: A Common-Sense Way to Apply Stucco to Concrete Block.
-- Martin Holladay
Thanks Martin.....my apology for the lack of clarity.
The 6" block is actually the four perimeter walls of a 2' X 6', 35' tall fireplace chase. Its on the outside wall of the home. I would typically do a 4" brick veneer here but due to the height above the eve line (15') I need more structural. After this, I am left with no room on the exterior foundation for brick veneer and I don't want to hang steel for a ledge or do siding so a stucco type is my preference.
Considering this, any more thoughts?
Phil Ternes
Consor,
Chimneys that are inside of a home's thermal boundary perform better than chimneys that are outside of a home's thermal boundary. Ideally, therefore, this chimney chase will have insulated walls. So EIFS is still the easiest way to go.
Builders often too a poor job of air sealing this type of chimney chase. There are lots of opportunities for bad details here. Make sure you have a discussion with your builder about where the air barrier is located. I also advise you to perform a blower-door test to confirm the performance of the air barrier.
-- Martin Holladay