Dan has an older stucco garage with water pooling against the base, causing damage to the stucco. He’s also dealing with cracks in the drainage channel and is unsure of the best materials to use for repairs. Let’s tackle these concerns step by step.
Question from Dan:
Could I please trouble you for some advice? I have an old stucco garage with some drainage issues. The water sits against the stucco and it eats away and comes underneath.
I don’t know if it is better to cut off the bottom inch or so and replace with hydraulic cement or just stucco and seal. Also, for the cracks in the drainage channel, is it better to fill the voids with hydraulic cement or self-leveling joint sealing sealant? Thanks.



Answer: Hi Dan, thanks for reaching out! Let’s break this down into two parts: addressing the damage to the stucco and fixing the drainage channel cracks.
Stucco Damage from Water Pooling
Water pooling against the base of your stucco, as shown in your photos, has caused significant deterioration. It’s good you’re addressing this now to prevent further damage. Let’s focus on practical solutions given your situation:
- Option 1: Cutting Off the Bottom and Using Hydraulic Cement
Cutting off the bottom inch or so of the deteriorated stucco and replacing it with hydraulic cement is a solid choice. Hydraulic cement is durable, water-resistant, and will help create a barrier to prevent further water intrusion.
This option works well for the visible damage shown in your photos, where the stucco is crumbling and exposing the underlying materials. - Option 2: Stucco Repair and Sealing
If you want a simpler fix, you can patch the damaged areas with stucco and seal it with a waterproof masonry sealer. While this won’t be as durable as hydraulic cement in areas prone to pooling, it’s a cost-effective way to improve the appearance and provide some protection. - Recommendation: Based on the extent of the damage in your photos, I really recommend replacing the framing and any other damaged or compromised parts of the wall first but using hydraulic cement for the worst sections should ensure a longer-lasting repair whether you do that or not.
Fixing Cracks in the Drainage Channel
Your drainage channel cracks, as seen in the images, are contributing to water pooling and need to be addressed to improve overall drainage:
- Hydraulic Cement: For larger cracks or voids, hydraulic cement is ideal because it provides a strong, watertight repair. This would be a good option for the more significant gaps visible in your photos.
- Self-Leveling Joint Sealant: For smaller cracks in the drainage channel, self-leveling sealant is easier to apply and accommodates minor movement over time. This can help ensure a smooth surface and prevent further cracking from occurring.
Preventing Future Issues
To avoid recurring problems, it’s important to address the root cause of water pooling and these can be quite extensive and expensive but it is worth mentioning...
- Improve Grading: Ensure the ground slopes away from your garage to direct water away from the stucco.
- Install a Drainage System: Consider adding a French drain or trench drain to catch and redirect water before it reaches your garage.
- Seal Regularly: Apply a waterproof sealer to both the stucco and the drainage channel to provide extra protection against water damage.
Addressing the drainage issue is key to preventing future damage, so improving the grading or installing a drainage system will go a long way. Let me know if you have more questions or need further guidance!