Why Use Stucco For My Home?
Stucco has been used in architectural structures since the Greek and Roman era and during the Renaissance. It spread throughout Europe and gradually became popular in America. Stucco is a finishing plaster composed of sand, lime, water and other ingredients. It is a strong, attractive and damage resistant covering for walls and ceilings. It is an excellent building material for hot areas as it helps to regulate the temperature. It is non-combustible and its surface burning properties include no flame spread and no smoke development.
Currently, there are two distinct types of Stuccoes –
Traditional/Hard Coat Stucco – This is basically cement mixed Stucco. The traditional stucco is durable and able to withstand harsh environments. It is porous and can breathe, so, dries quickly and resists water damage.
Conventionally, lime was used with sand and water. As lime is slightly soluble, the mixture has a self-healing tendency. At present, stuccoes are usually made up of Portland Cement, sand and water resulting in a hard and brittle variety.
To install hard coat stucco, first the substrate is installed followed by a metal lath and then a coat of stucco is applied with a trowel. It is allowed to set and then another coating is applied. Normally, the process involves a scratch coat, a brown coat and a finish coat (may be colored).
Stucco can also be applied on a paper and wire. The coats should be thicker. The first coat (scratch coat) covers the wire. It needs to be scratched as soon as it sets. The second coat (brown coat) gets bonded to this coat and as usual the finish coat is the outermost layer.
Synthetic Stucco – Since 1950s, a number of houses were built using a variety of synthetic materials resembling stucco. Fibers and synthetic acrylics were added to the cement stucco mixture to add strength and flexibility. In general though, the synthetic stuccoes are less heavy and hence, more susceptible to a hard blow. They are a one-coat stucco system unlike the three-coat traditional ones.
The most common one is EIFS or Exterior Insulation & Finish Systems. They are glued or mechanically attached to the substrate and usually composed of three layers. The innermost layer, mostly made up of polystyrene like material, is a foam insulation board. The second layer is a base coating attached to a fiberglass mesh and the final layer is a finish colored coat. It became popular because of its easy installation, low cost and better insulation properties. The only disadvantage is moisture absorption which causes water damage to the building.
A variety of stucco colors/paints are available. Colorants are inorganic pigments which can adapt with the high pH value of cement. They can be either natural like, Ochers and natural earths or artificial, such as man made Iron Oxides. Natural colorants remain unaffected to UV rays and are more pleasant to our eyes. But, the range of shades and the tinting strength is less when compared to manufactured colors. Man made colors, on the other hand, offer a wider range of shades such as dark blues and greens as well as various earthy tones like, yellow, brown and reds. They also possess excellent UV stability due to the presence of inorganic pigments.
What to Know About Exterior Stucco Contractors
When fall inevitably comes each year, home owners who have been "thinking about" renovating their home with stucco suddenly realize they're running out of time, and give their contractor(s) a call. All of them. The resulting mayhem is an influx of home owners requesting a contractor do their home before winter so that they can enjoy their new beautiful home's look and increased energy efficiency. The contractors who make most of their money during the summer, begin to quicken the pace to accommodate this work before winter, often at the expense of quality. Each stucco construction project is not given it's due diligence, and critical portions of work are ignored such as contracts, weather barriers, proper surface leveling, warranties. Even not so "critical" but finishing aspects such as proper moulding selection is often ignored.
The average stucco construction renovation will take about 3 weeks, with a 2 week lead time. This can all be expedited with an experienced project manager, but most home owners opt to do the managing themselves, sometimes naively. With 5 full weeks required from the time you SCHEDULE the contractor, you really need to start looking for prices about 7 weeks in advance. Generally, the stucco construction season (for Toronto) will end towards the end of October. This means that if you're not looking at the beginning of September, you need to exercise a degree of caution about getting your project done before temperatures drop below acceptable levels. EIFS manufacturer guidelines state:
Do not proceed with application of base coat and/or finish coat at ambient air temperatures below 5C (41F)
Applying the material in these temperatures may cause it not to cure properly, resulting in improper adherence to the substrate, and subsequent delamination - in English, your walls could fall off. The weather can't be blamed for all problems though, and you do need to pay attention to make sure your contractor is doing all the layers properly. No weather barrier means that water can get onto your substrate. Adhesive not being done in vertical channels means that water can become trapped against the substrate. Not meshing styrofoam fully can mean cracks developing, and water infiltrating your walls. Not mixing the base coat in the proper ratios or applying it too thin can result in a weak and easily damaged wall surface. Not spending enough time "floating" (troweling) the finish coat can result in discrepancies in the texture, which really just looks awful. Having a third party project manager or home inspector come once or twice a week to inspect the quality of work for a few hundred dollars is very inexpensive compared to having to rip the stucco off your walls and redo it in 5 years.
Aside from application problems, you want to ensure you give yourself enough time to really think about what you want for this project. Too many home owners take the first, cheapest guy they find and go ahead without a contract, resulting in them not knowing exactly what is "included", and a lot of "extras". Doing your due diligence includes researching items you need included with your project, such as flashing, replacing old substrate, whether a weather barrier is required or not, in what order to proceed with renovations... the list goes on. In short, don't go into a project without being fairly confident you know you have the details worked out, and use a contract to clarify those details.
Even moldings are sometimes not given their due consideration. Proper molding selection will help manage water runoff, further protecting your walls. They can direct water away from window openings - which tend to be the most susceptible to water damage, and kick water off the walls - preventing the black or white water streaks you often see below window sills. Using a wall band at the base of a high traffic wall can protect your wall from being hit by snow shovels, moving furniture and even cars. The same protective quality can be said of quoins or pilasters on the corners of your wall.
When renovating your home, it's important to focus on more than just the initial cost of stucco construction. You need to do your research to ensure you don't get "ripped off", and you need think about future maintenance. If you can't realistically put in the time to make sure you have everything included, get multiple estimates, have a contract made, and think about how to reduce future maintenance costs, you are better off waiting until spring to have your project completed. You will lose 1 winter of lowered heating costs, but prevent thousands of dollars in possible damage.