Stucco is undeniably one of the most durable and attractive finishes you can have on your exterior walls. It is fire-resistant, affordable, and low-maintenance. If you want to install stucco, the recommended method is to apply it over sheathing.
The sheathing acts as a backing material for the stucco to adhere to. But can you install stucco without sheathing? Is this even acceptable? Keep on reading to learn more.
Can You Install Stucco Without Sheathing?
Yes, you can install stucco without sheathing, but it’s not advisable. A lot of homes built in the 60s had such a setup.
But today, it’s rare to find a home where stucco is installed without sheathing. If you have hired a contractor and they are recommending this approach, decline their offer without hesitation.
To install stucco without sheathing, you need three main things; interior studs felt paper, and chicken mesh or lath. In this scenario, the felt paper and chicken mesh are nailed to the interior studs, and stucco is applied.
Why Shouldn’t You Install Stucco Without Sheathing?
If you inquire from professional contractors, they will advise you not to install stucco without sheathing. Doing so often results in the following issues.
• The Walls Lack Structural Strength
Stucco is a durable exterior finish. But if you apply it without sheathing, the wall will lack adequate structural strength. In theory, you will be building a stucco box, and that’s not acceptable.
You can’t compare the stability of stucco to sheathing with that of applying it to interior studs and laths. Your project may not last very long.
• Such a Setup Makes Repairs and Remodels Difficult
If there is no sheathing behind the stucco, remodels and repairs of your walls will be pretty complex and tedious. The presence of sheathing makes it easier for you to remove, repair or replace worn-out stucco.
But if there is only wire mesh and felt paper, during repairs, you may end up damaging the entire wall because there is no backing material acting as a shield.
Is It Common to Find a House that Has Stucco Without Sheathing?
This setup is very common in homes that were built during the 60s. A few decades ago, OSB and plywood panels weren’t very popular.
Therefore, most homes were built that way in the past. If you only work on modern homes, this setup may seem new. But if you have some experience dealing with old houses, this shouldn’t be surprising news to you.
Fast forward to the 21st century, this is not an accepted method of installing stucco. That is why I mentioned earlier, you shouldn’t agree to a contractor who wants to install stucco without sheathing.
Even if they provide you with a warranty, you will have to face the problems mentioned above in the future. And it’s not worth it.
How to Repair Stucco that was Installed Without Sheathing?
Have you discovered that the stucco in your home was installed without sheathing? Are you interested in repairing some of the worn-out stucco on your walls? It can be confusing how you can approach such a problem.
The best solution here is to demolish the entire wall and build it correctly. But this can be quite expensive and time-consuming. So, what you need to do is get an angle grinder, preferably one with a diamond grit blade.
You can then cut through the stucco that you wish to replace gently. You should avoid digging deeper into the stucco with the angle grinder as you may cut the lath or felt paper.
In most cases, the stucco is usually 1.5″ deep. Keep that in mind as you cut out old stucco from your wall.
Using a hammer to remove old stucco on your walls can be tempting. But I don’t recommend using this tool. A hammer does a marvelous job of removing stucco.
But since there is no sheathing, there is a high risk of knocking into the drywall on the interior of your walls. Also, stucco without sheathing isn’t structurally sound. Therefore, you may find yourself removing more stucco than you intended to.
Using an angle grinder is the only way you can avoid damaging the chicken mesh and felt paper. Remember, these two materials play a crucial role in your wall’s design. If you interfere with them, you risk damaging the entire stucco wall.
Do Current Building Codes Accept Stucco Without Sheathing?
That will depend on where you live and how tolerant the local inspectors are. In the past, building codes weren’t very strict.
Most homes were built without even inspection. This is why many old houses have stucco without sheathing.
However, if you are building a wall today, no inspector will approve stucco installation without sheathing. You must follow the recommended method of building stucco, where sheathing is mandatory.
In case you discover your home has stucco without sheathing and you are in the process of remodeling it. The inspector may give you the green light because your home was built that way.
Therefore, you may not have to spend much money tearing down the wall and rebuilding it up to current building codes.
How Does Stucco Without Sheathing Prevent Water Entry?
When explaining how stucco without sheathing was built in the 60s, I mentioned that felt paper is one of the main materials used.
This was mostly an asphalt-impregnated product that could prevent water from passing through. This paper is what was used to prevent the entry of water.
If your stucco was installed without sheathing, you need to be mindful of this felt paper when repairing it. If you damage it, water will start to seep through. And moisture damage may begin to occur within the wall. This will also attract mold.
What’s the Best Sheathing to Use Under Stucco?
Having ruled out that stucco without sheathing is not acceptable. If you intend to install this finish on your exterior walls, it’s crucial to identify the best materials you can use underneath it.
There are many types of stucco sheathing, and each has its benefits. I will briefly list some of them so you can choose the ideal option.
• Wood Sheathing: For years, wood has been the go-to sheathing material. That’s because it’s cheap and readily available. The wood sheathing is categorized into; OSB and plywood.
OSB is the most affordable of these two, and plywood is stronger and more resistant to water. If you settle for wood sheathing when installing stucco, make sure that you leave gaps for expansion and contraction.
• Cement Board: Today, a cement board is the best sheathing to use when installing stucco. This is a mixture of cement and fiberglass strands.
Unlike wood, it is resistant to water damage, and it’s moderately priced. A cement board is a highly durable stucco sheathing option.
• Exterior Gypsum: This is just like drywall, only that it has been formulated to be water-resistant and a bit stronger. Exterior gypsum cuts pretty easily.
Therefore, installation is quick and effortless. Exterior gypsum has a fair price tag. However, it’s not available everywhere and is mostly suitable for commercial buildings.
Should you find yourself in a scenario where you plan to erect a wall and want to finish it up with stucco, these three are the top sheathing materials you should consider.