Got Stucco? Get informed! By: Mark Benzel
If you have, or are considering purchasing, a home with stucco built in the last 50 years in the mid-Atlantic region there's critical information that you need to know regarding moisture that can become trapped behind the stucco. The important points in this discussion apply to homes with exterior stucco cladding applied over wood frame substrate. Most homes with stucco in this region built prior to the mid-1960s have the stucco cladding applied over a masonry substrate, and while these homes can exhibit problems they are not nearly as prevalent as those in homes with stucco over wood frame.
There are two types of stucco. Synthetic stucco, which is an acrylic coating over a foamboard base, and masonry stucco, which is typically three layers of cement mortar applied over a wire lath. Both types of stucco can exhibit similar problems with moisture retention, however this discussion will focus on masonry stucco as that is by far the more common type used in the mid-Atlantic region.
The first most important point that you need to know is to get your stucco inspected by a qualified stucco analyst. Knowledge is power and a properly conducted stucco inspection will give you valuable information about the condition of your stucco and the substrate behind it.
There are many different kinds of exterior cladding for homes and all of them have benefits an drawbacks. While no cladding is perfect, for many years masonry stucco was thought to be close. It was durable, attractive, relatively maintenance-free, inexpensive to install, and provided stiffening to the structure, sound deadening, and protection from intruders and all types of weather. However, masonry stucco can develop problems such as cracking, delamination, separation from the substrate, and most importantly, but until recently, least understood, moisture retention.
For many years masonry stucco was installed as if it would keep out moisture entirely. However it has come to be realized that there are many ways that moisture can find its way behind stucco, and not just from the outside of the structure. Liquid water can find its way behind the stucco at cracks, missing roof kickout flashings, utility penetrations, joints between the stucco and windows, doors, or other trim
materials, or by leaking through the windows or doors themselves; and moisture vapor can find its way behind the stucco and condense as it migrates through the wall system from inside of the structure to the outside. Much of this moisture intrusion is exacerbated by poor detailing during stucco installation, which is very common on homes built during this time period. Because stucco was expected to prevent moisture intrusion, it was not installed with any provision to allow moisture to escape. Consequently, any moisture that gets behind the stucco frequently becomes trapped, where it can cause deterioration, rot, and mold in wood substrate materials.
While these deficiencies are serious, they can be repaired. The scope of work required to implement these repairs can vary from some basic detailing procedures, to complete removal and replacement of the cladding. However, the two most important elements of any repair project are the installation of roof kickout flashings, and a mechanism to allow the system to drain properly. A properly conducted stucco
inspection by a qualified analyst, which typically involves drilling holes in the stucco at critical locations to obtain moisture readings from the substrate, can provide specific information about which details are missing, or poorly executed, and the condition of the substrate materials. This information allows the analyst to make specific recommendations about the required scope of repairs. In many cases homes
with significant moisture damage appear to be in perfectly good condition from both inside and outside. Because the damage is located in the middle of the wall structure, outward appearances cannot be relied on to accurately indicate the presence of problems. The only way to know for sure the condition of the wall system is to have it properly inspected.
If you are looking at purchasing a home with stucco, understand that it can be repaired to become a sound structure with a properly operating cladding system, but it is essential that you have a proper stucco inspection included as part of the contract contingencies.
If you currently own a home with stucco cladding is important that you do not ignore the issues and assume that there are no problems. The earlier the stucco deficiencies are identified and repaired, the less the damage and scope of repairs will be. Avoiding the problem will not make it go away. If you put your house up for sale in the future it will almost certainly be inspected, with repairs being required prior
to completion of the sale. Any competent real estate agent will require their buyer clients to include the stucco inspection in an offer contract and most mortgage companies and corporate relocation departments are requiring stucco inspections as a part of any purchase. Having your home inspected now will give you the flexibility to plan for any necessary repairs well ahead of a potential future sale.
If you have, or are considering purchasing, a home with stucco built in the last 50 years in the mid-Atlantic region there's critical information that you need to know regarding moisture that can become trapped behind the stucco. The important points in this discussion apply to homes with exterior stucco cladding applied over wood frame substrate. Most homes with stucco in this region built prior to the mid-1960s have the stucco cladding applied over a masonry substrate, and while these homes can exhibit problems they are not nearly as prevalent as those in homes with stucco over wood frame.
There are two types of stucco. Synthetic stucco, which is an acrylic coating over a foamboard base, and masonry stucco, which is typically three layers of cement mortar applied over a wire lath. Both types of stucco can exhibit similar problems with moisture retention, however this discussion will focus on masonry stucco as that is by far the more common type used in the mid-Atlantic region.
The first most important point that you need to know is to get your stucco inspected by a qualified stucco analyst. Knowledge is power and a properly conducted stucco inspection will give you valuable information about the condition of your stucco and the substrate behind it.
There are many different kinds of exterior cladding for homes and all of them have benefits an drawbacks. While no cladding is perfect, for many years masonry stucco was thought to be close. It was durable, attractive, relatively maintenance-free, inexpensive to install, and provided stiffening to the structure, sound deadening, and protection from intruders and all types of weather. However, masonry stucco can develop problems such as cracking, delamination, separation from the substrate, and most importantly, but until recently, least understood, moisture retention.
For many years masonry stucco was installed as if it would keep out moisture entirely. However it has come to be realized that there are many ways that moisture can find its way behind stucco, and not just from the outside of the structure. Liquid water can find its way behind the stucco at cracks, missing roof kickout flashings, utility penetrations, joints between the stucco and windows, doors, or other trim
materials, or by leaking through the windows or doors themselves; and moisture vapor can find its way behind the stucco and condense as it migrates through the wall system from inside of the structure to the outside. Much of this moisture intrusion is exacerbated by poor detailing during stucco installation, which is very common on homes built during this time period. Because stucco was expected to prevent moisture intrusion, it was not installed with any provision to allow moisture to escape. Consequently, any moisture that gets behind the stucco frequently becomes trapped, where it can cause deterioration, rot, and mold in wood substrate materials.
While these deficiencies are serious, they can be repaired. The scope of work required to implement these repairs can vary from some basic detailing procedures, to complete removal and replacement of the cladding. However, the two most important elements of any repair project are the installation of roof kickout flashings, and a mechanism to allow the system to drain properly. A properly conducted stucco
inspection by a qualified analyst, which typically involves drilling holes in the stucco at critical locations to obtain moisture readings from the substrate, can provide specific information about which details are missing, or poorly executed, and the condition of the substrate materials. This information allows the analyst to make specific recommendations about the required scope of repairs. In many cases homes
with significant moisture damage appear to be in perfectly good condition from both inside and outside. Because the damage is located in the middle of the wall structure, outward appearances cannot be relied on to accurately indicate the presence of problems. The only way to know for sure the condition of the wall system is to have it properly inspected.
If you are looking at purchasing a home with stucco, understand that it can be repaired to become a sound structure with a properly operating cladding system, but it is essential that you have a proper stucco inspection included as part of the contract contingencies.
If you currently own a home with stucco cladding is important that you do not ignore the issues and assume that there are no problems. The earlier the stucco deficiencies are identified and repaired, the less the damage and scope of repairs will be. Avoiding the problem will not make it go away. If you put your house up for sale in the future it will almost certainly be inspected, with repairs being required prior
to completion of the sale. Any competent real estate agent will require their buyer clients to include the stucco inspection in an offer contract and most mortgage companies and corporate relocation departments are requiring stucco inspections as a part of any purchase. Having your home inspected now will give you the flexibility to plan for any necessary repairs well ahead of a potential future sale.