Stucco stands the test of time. Whether it’s your house or a historical monument, stucco has reputation to keep. Plaster, on the other hand is softer and a more ‘introverted’ material. However plastering is used as a common process for all building materials nowadays.
Stucco consists of Portland and lime. To give it a boost of strength, fiberglass strands may be mixed in the mud. Fiberglass helps the structure get sturdy and robust while keeping cracks away. We use sand in different proportions in every mix to curate a new texture. Finally, the mix is applied on plaster or the existing structure as a coating. The inner structure is coated beforehand with a layer of metal lath. It allows stucco to stick to a material that’s attached to the inner structure. Thus we have a building that will stand the Sun and the rain.
People have been calling stucco plaster for a long time. Plaster is a gypsum based building material. But the coating of plaster is popularly known as plastering in the United States. In the third quarter of the nineteenth century, stucco based houses spread over the U.S. followed by an influential book The Architecture of Country Houses (1850). The book described stucco as a cheaper, drier and warmer option for coating houses. It has been successfully used to insulate homes from heat and sound. The mix of plaster and stucco make a soundproof structure.
The appeal with plastering stucco is the prestigious look it gives the house. It can imitate expensive stones and marbles with proper lines and sections. Home owners may leave out stucco without painting because of its classic tone of color. The mix can be colored different shades depending on the color of the sand used in the mix. Diluting vitriol oil and mixing it with water, the mix is added to a yellow ochre to bring out a marble built look. It’s sophisticated.
Stucco has been reinforced with a few other materials to enhance its features. Oil and waxes are mixed to provide with water-repellent properties. Even though, water is a common enemy of stucco structures. Moisture penetrates the structure creating bubbles and weakens it. A proper mix save the house from extreme weather.
A clean and smooth surface struggles to hold stucco over a period of time. We apply metal lath underneath the mix to strengthen the bond between the surface and stucco. A typical coating of stucco consists of three layers. First two layers are known as ‘scratch’ which gives the surface to apply the final coating on. This layer has numerous scratches all over it. The inconsistency created by scratches create a stronger mechanical bond between first two layers. The final coating is generally lime-rich and finer. The inner plaster is kept wet to ensure it doesn’t suck water out of the stucco mix or it may cause the stucco layer to crack from drying out rapidly.
A clean and smooth surface struggles to hold stucco over a period of time. We apply metal lath underneath the mix to strengthen the bond between the surface and stucco. A typical coating of stucco consists of three layers. First two layers are known as ‘scratch’ which gives the surface to apply the final coating on. This layer has numerous scraches all over it. The insconsistency created by scratches create a stronger mechanical bond between first two layers. The final coating is generally lime-rich and finer. The inner plaster is kept wet to ensure it doesn’t suck water out of the stucco mix or it may cause the stucco layer to crack from drying out rapidly.
It’s in a contractor’s interest to suggest you to paint your stucco house. However, stucco itself does a good job of repelling water and rain. It’s not mandatory to put on a further layer on top of it. You may want to seal the deal with a layer of waterproof paint or sealant.
Can new stucco be applied over old stucco?
It’s doable. However, the new layer needs to be chemically consistent the former one. Your house should be inspected by a certified inspector who will find out the mix used to build your house and then recommend a suitable stucco mix. There are numerous things to add to a stucco mix for diverse features. We suggest you to contact a specialist to inspect the current condition of your walls. Another thing is that older walls tend to have cracks that can propagate rapidly. So a new layer of stucco will last a shorter time than its original life span.
Should I seal stucco?
Moisture is a common complaint of stucco home owners. Stucco is a water-tight material but depending on the composition, water can penetrate and damage the structure. To seal a stucco building, we recommend silicon-based masonry/concrete sealers. These materials penetrate stucco and closes the path for moisture to enter. If the structure is older, the hairline cracks can be covered by elastomeric coatings. These are flexible and porous. So the cracks are covered even after these have expanded.
When should I replace my stucco?
In absence of harsh conditions, your house may withstand 50-100 years. If it’s made of synthetic stucco or EIFS, then your only concern should be water leakage. Unless it happens, you should enjoy a long lifespan from these materials. Identifying issues is important as it may shorten the lifespan and call for an urgent repair. Please read this for more information.