Stucco House Problems? Install Stucco the Right Way with Matt Risinger
Even the best homebuilders can encounter issues with water leaking through stucco.
The Build Show’s Matt Risinger shares some of his stucco failures, and how you can avoid the same fate with his proven step-by-step installation method.
What do stucco and your average concrete sidewalk have in common?
Both are cement-based. Both soak up water. And both should generally last a VERY long time.
Obviously, they differ with sidewalks being on the ground, and stucco generally being applied over wood-framed houses – and this is where stucco house problems arise.
Almost every remodel I’ve undertaken where I found serious rot in the wood, you couldn’t tell from looking at the stucco exterior that a huge problem was waiting underneath it.
So, let’s examine some recent stucco failures I’ve seen, and see if we can find a common theme.
A recipe for damaged, wet stucco
First, these pictures are from a 15-year-old wood-framed restaurant with stucco cladding. This was a traditional 3-coat (roughly ¾” thick) stucco with two layers of tar paper on top of 1/2″ plywood sheathing.
There was damage in multiple locations on this project, including some scuppers that leaked behind the stucco. But, the most troubling of the rot I saw on this project was the damage found in the bottom 3’ of the stucco closest to the ground, with no damage above.
As I investigated this failure, I found the irrigation sprinklers were wetting the stucco wall layers and the tar paper weather barrier underneath could not dry out. This constant wetting without drying led to massive failure in the stucco wall construction.
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Proper stucco application techniques go out the window
Let’s look at some more stucco house problems. In this project, I’m replacing some wood windows in this 20-year-old home, and we again found lots of issues in the bottom 3-4 feet of the walls where they meet the foundation.
We also found lots of rot at the base of these window sills where water was getting in past the windows.
Filling the gap in stucco house problems
Stucco can be a beautiful cladding – but because it’s cement-based, it’s porous and soaks up water like a sponge. So, knowing that we can have issues with water, what’s the best path to take with a stucco installation?
An air gap!
If we add a space behind the stucco, keeping it off the building by using an air gap product, it creates both drainage and air flow for much-needed drying.
I really like Dörken’s DELTA®- DRY STUCCO & STONE for this air gap. It’s a dimple mat with a mortar screen that makes this air gap for exterior stucco wall constructions simple to achieve.
This simple change of adding an air gap behind the stucco via a stucco water barrier affords several benefits. This reservoir cladding can now dry both to the front and the back, ensuring your WRB won’t have water sitting against it. And if the house does need to move moisture to the exterior through the WRB, it will be able to do that much easier.
A step-by-step stucco installation method
1. Install a base-wall flashing.
I’ve used a lot of peel & sticks over the years, and Dörken’s DELTA®-FLASHING works great. The Blue Peel & Stick in this picture is the base wall flashing. It will protect that vulnerable joint between foundation and framing from both water and air coming in. (Both are big problems for any wood-framed house.)
2. Install a high- quality water resistive barrier (WRB) and shingle this over the base-wall flashing.
At the base of the wall I install a bug screen (think brillo pad) and roll out Dörken’s DELTA®-DRY STUCCO & STONE. (I’m not showing it here, but you’ll want to ensure you have an air gap at the top of the stucco wall layer, too. This will ensure air flow behind the stucco and out the top. We used the bug screen at the top of the wall with a stucco “L” bead to terminate the stucco about ½” down from the soffit.)
3. Install a wire lath as normal, but with ½” longer staples. Install scratch coat of stucco directly onto the mortar screen of the DELTA® -DRY STUCCO & STONE.
The first coat of traditional stucco is called the ‘scratch coat’. This coat tooths into the lath and holds it onto the building. You can see here that the fabric on the DELTA® -DRY STUCCO & STONE prevents the stucco from clogging the pores of the drainage mat.
Take a look:
The finished house is beautiful and you can’t tell that the stucco has a ½” air gap behind it. I truly believe this is a best practice for any successful stucco install, in any climate. This simple product, with its air gap, is a game changer for stucco and building durability.
This home was designed by Nick Deaver, AIA and built by Risinger & Co., and the stucco is an integral color (meaning no paint) by LaHabra. But most importantly, the air gap behind the stucco will ensure a couple generations of durability, easily!