Chapter 16 – Inspecting Exterior Siding Materials &
Exterior Walls
We will continue our inspection with siding materials and exterior walls.
There are several materials used to construct and finish the exterior of your home. We will cover the more common materials such as T1-11 wood siding, lap siding, shingles, logs, fiber-cement materials, vinyl, aluminum and masonry walls such as stucco, concrete block and brick and mortar.
Log construction is not common but important to consider. There are several log home manufacturers and the style of construction can be as unique as the trees themselves.
Inspect the logs for deterioration at areas where the end grain is exposed to the weather. Record the presence of any stains or areas where water intrusion may have occurred. Repairs to log structures are a specialized trade and are referred to professionals skilled in such work.
Concrete and brick walls are more than a siding as they provide a complete structured wall. The materials have little flexibility so movement will leave cracks.
Look for cracks or deterioration of the concrete, bricks or mortar. Deterioration in the masonry could be caused by exposure to detrimental elements.
Peeling paint and a white powdery substance called efflorescence on the surface of the wall could be an indication of moisture penetrating the walls.
Stucco is cement or a synthetic material made of an aggregate, a binder and water which is applied wet and hardens when it dries. Movement in any structure with a stucco finish may cause cracks. Other causes of cracks in stucco include poor application or faulty materials.
Standard stucco applications are multiple layers of material called the scratch coat, the brown coat and the color coat applied over a moisture barrier and screen mesh attached to the exterior walls.
Years ago stucco was applied all the way to the ground. The aggregate nature of stucco allowed it to wick or draw moisture out of the soil. Deterioration in the wood framing at the lower sections of the walls resulted. Evidence of water damage can sometimes be observed in the crawl space around the perimeter of the building.
Installation standards now require that stucco terminate 4-6″ above the ground and 2” over wood, masonry, concrete or composite decking.
On modern stucco applications a weep screed is installed at the base of each wall which allows moisture to drain out of
the wall. The weep screed should not be obstructed by landscaping materials, vegetation or planter boxes. The weep screed should not be covered or imbedded in any walkway or structure that will prevent the free flow of moisture.
Single course (one layer) stucco applications are being used which, if applied per the manufacturer’s specifications, function as well as the multiple layered products. One such stucco product is called EIFS (Exterior Insulation and Finish Systems).
Problems including water intrusion around exterior doors and windows can occur in any type of stucco application. However, the EIFS installations appear to be particularly problematic. Water intrusion causes damage to the interior framework of the building and can result in water leaks, stains and organic growth.
Your previous inspection of the interior may have revealed problems related to water intrusion such as stains, loose texture or organic growth. If you found such issues present there could be a problem with the exterior stucco application.
Inspect for cracks. Cracks in stucco are common. If the product was properly installed the moisture that naturally penetrates the surface will evacuate through the weep screed.
Record the presence of any stains at the exterior of the building.
Although their source may be difficult to ascertain stains should always be carefully investigated.
There is a blink in Chapter 26, Conclusion and Resources, that will take you to an online album containing a series of photos and commentary from a Pennsylvania homeowner who experienced a nightmare related to poor craftsmanship on her stucco home.
If you have stucco siding, go to this site before you inspect your siding. In fact, EVERYONE reading this eBook should have a look at the photos. This additional education is excellent.
Buyers present during an inspection often asked questions about things they observed while looking around the building. I explained that I needed to complete the inspection before I could know if any single issue could be a symptom of a larger problem.
I informed them that the building was telling me a story and until I had the whole story I would not be able to determine the consequences of any one particular item. The story is not fully told until we have looked at everything.
T1-11 panel siding (originally know as Texture 111) is very common and is essentially an exterior grade textured plywood or OSB (oriented stand board) product installed over a felt or approved vapor/moisture barrier. When properly cared for it will last many years.
T1-11 is a wood product and is susceptible to water, weather and pest damage. Inspect for stains and record your findings.
Rust stains from the nails holding any type of siding material in place indicate two potential problems: the wrong nails were used and/or there may be moisture in the wall.
Inspect the siding for signs of delaminating and deterioration.
“Wood to soil contact” is a very common problem and is a note in every home inspector’s digital library. T1-11 siding material should be 4-6 inches above the soil and at least 2 inches over wood, masonry, concrete or composite decking.
Use the scratch awl to probe around questionable areas where the siding has been in contact with the soil or where water run off from the roof or any intercepting surface may have compromised the material. Home inspectors and termite contractors both look very carefully at T1-11 siding for signs of warping and deterioration.
Damaged T1-11 may be found around wood or composite deck boards where the boards have been installed directly against the siding material. Debris caught in the tight space between the deck boards and siding traps water and over time ruins the materials. Metal flashing between the siding and decking prevents this problem from occurring.
The photo gallery shows examples of damaged siding caused by this issue.
Moisture in any wood material is extremely susceptible to insect infestation and deterioration.
Vertical lap siding, shiplap siding and shingles are inspected for warping, looseness, holes, stains and water damage.
Siding materials on buildings constructed until the mid 1980’s may contain asbestos. The best thing we can do to preserve these materials is to keep them cleaned and painted. If removal is required it must be done by a licensed hazardous material abatement contractor.
Hardboard materials used in the 1970’s and 1980’s have been known to be problematic due to water intrusion breakdown. Class action suites have been filed over the years against the manufacturers of these materials and the products have been removed from production. Such materials can be in vertical lap siding or 4×8 sheet configurations.
Symptoms of failure include bowing, swelling, material that is soft or spongy to the touch and edges that are coming apart.
This hardboard material was common on manufactured homes.
Fiber cement siding (FCS) is a composite material made of sand, cement and cellulose fibers. It was developed to replace widely used asbestos cement sheeting products manufactured until the 1980’s.
In appearance FCS usually consists of overlapping horizontal boards imitating wooden cladding, clapboard and imitation shingles. FCS is also manufactured in a sheet form and is used not only as cladding but also as a soffet or eave lining and as a tile underlay on decks and in bathrooms.
FCS is resistant to water and insects and is non-combustible. The material is subject to cracking. Cracks can be filled, lightly sanded to protect the texture and repainted.
Vinyl and aluminum siding materials have been in use for many years. Penetrations or holes in the material are subject to water intrusion. Older vinyl products are subject to cracking and deterioration. Aluminum siding is subject to dents from impact.
Exterior trim boards are very susceptible to deterioration. Trim installed over the top of any door or window should be flashed and bevel cut to slope down and away from the wall. The flat edges of trim create a shelf where rain and snow can collect and seep back into the wall. The outer corners of trim boards installed under windows seem to be susceptible to deterioration. Check these areas for deterioration with the awl.
Paint is a wonderful product for maintaining wood and reducing the chance of water intrusion.
Caulking the trim is a cheap and temporary construction practice. Any surface that does not slope down and away from the building can become a location for water intrusion and needs to be inspected carefully.
Seal all openings in exterior walls to prevent the entry of vermin and insects.
Move firewood or any wood materials away from the walls.
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EXTERIOR SIDING MATERIALS & EXTERIOR WALLS FINDINGS:
REMEDIES AND SOLUTIONS
Siding materials are the outer skin of your building. Your inspection may reveal minor issues you or a handyman can resolve. This will cost a lot less money than your buyer’s contractor will charge.
Damage or holes from poor craftsmanship, animals, weathering and general wear and tear will require qualified persons to evaluate and restore.
Any cracks in a concrete block wall will require further investigation for a possible broken footing or foundation. If further investigation reveals such damage, it is recommended that a licensed structural engineer be consulted.
Most stucco cracks can be repaired or patched by a qualified painter. Larger cracks or missing pieces indicate more a serious condition. Consult a licensed stucco contractor.
Damaged or deteriorated siding materials of all types should be repaired or replaced by a qualified tradesman.
A qualified tradesman can replace wood trim boards. Woodpeckers also damage wood siding and exterior trim. Before holes and damage are repaired consult with a licensed pest control company for the eradication of vermin.
PHOTO GALLERY
An additional 70 images with descriptive captions are available in the 27 Dollar Home Inspections eBook.
Click here to move on to
Chapter 17 – Inspecting Chimneys & Fireplaces

