There are a variety of exterior surfaces that are commonly found on homes, each with its own advantages and disadvantages. As a homeowner, your single-most important consideration with regard to exterior surfaces should be proper maintenance and upkeep. The following provides some helpful information to assist you in your evaluation of the exterior surface on your home.
Brick is probably the strongest and most dependable of the building materials utilized in residential construction. Many homes constructed with full masonry brick and block structures are still in existence after being subjected to the environmental elements for hundreds of years.
The first thing you may wish to determine is if the walls are a brick veneer or solid masonry type construction. The best and easiest way to tell is to look for a wood sill plate under the floor joists in the basement or crawl space. If a sill plate is present, you know for sure that it is a veneer wall. If there is no sill plate, you can be about 95% sure that it is an 8 inches or thicker masonry wall. Veneer walls should have weep holes at or close to the bottom of the wall, visible from the outside. Brick veneer is a 4-inch layer of bricks used only as a facing material, and is not load bearing. Solid masonry walls, 8 inches or thicker, will utilize 2 layers of brick and/or concrete or cinder blocks to carry the floor and roof loads of the residence.
The bricks most builders use in today’s construction are referred to as “face” bricks. These bricks are used as a veneer on frame buildings. The masonry brick veneer should be attached to the supporting wooden framing of the walls. The most common of the brick ties is a corrosive-resistant, galvanized steel metal strap/tie, which is essentially a one-inch strip of corrugated sheet metal. The ties are nailed to the wood framing, then bent outward to lay over the courses of the brick and embed into the mortar. The corrugated sheet metal should be a minimum of number 22 U.S. gauge material and should be placed no more than 24 inches on center, horizontally within the wall.
Each tie that is installed should not support more than three square feet of wall area. Brick veneer ties can also be made of a stranded wire that should be at least a number 6 U.S. gauge wire, which is embedded in the mortar joint of the wall. Many houses have brick veneer that has been improperly tied to the building framing. Improper ties may result in bowing of the brick veneer wall and cracking at weak areas, typically above and below the window and door openings. Since the ties are concealed within the mortar joints of the brick, it is important that a careful inspection be conducted of all masonry surfaces. Look for bowing, cracking or shifting of the brick away from the structure at window and door areas and at the end of the wall. Exterior masonry veneer should not be attached to any wooden component at any point more than 25 feet above the grade level.
Check the veneer wall on the inside for evidence of water penetration. If water is getting into the wall or condensation is developing, the flashing should be directing the water to the weep holes. If the flashing is not correct, water stains or water may be seen at the sill plate area.
Brick mortar deteriorates over time. The amount of time is dependent upon the mortar mix, workmanship and the brick. Mortar problems should be apparent. If the brickwork has to be pointed, the cost will, for the most part, be dictated by its hardness. The cost range for brick pointing is wider than any other component, due to this hardness issue—approximately $3.00 per square foot (SF) for soft, easy to cut out mortar; more than $10.00/SF for very hard mortar.
Brick deterioration generally occurs in one of two ways—spalling and deterioration. Spalling is caused by moisture getting into the brick, freezing and 1/8 inch to 1/4 inch of the surface separates and falls off. This damage will be apparent, and the remaining part of the brick will still be relatively hard.
Deterioration of soft brick looks like it is being worn by natural elements. This is typically a salmon or an orange, clay brick that was intended for use on the inside layer of a solid masonry wall.
Spalling and/or deteriorated bricks can be chiseled out and replaced. In an 8 inch wall, you might easily take out 20 bricks at a time without serious concerns about the structure. Consult a structural engineer if the damage is extensive or if you are unsure.
Stucco is an exterior masonry product made from sand, Portland cement and water. It is generally applied over metal lath or masonry in two or three coats. The first coat is approximately 3/8 inch thick, and is called the “ground” coat. The second coat is also approximately 3/8 inch thick, and is called the “scratch” coat. The third coat is the finish coat and is approximately 1/8 inch thick. The total thickness should range from 3/4 inch to 1 inch.
Stucco over frame is likely to exhibit hairline and alligator cracking because the frame is much more flexible than the stucco. Expansion/contraction joints should be installed in stucco installations every 144 square feet of surface without penetrations however, they are rarely found in residential construction. If the cracks cannot be filled with paint or a minimal amount of caulk and paint, there may be a problem. The problem could be workmanship, stucco mix, wet lumber, a large number of openings, or the structure.
A common problem with stucco as it gets older is that water may get behind it and cause the stucco to separate from the wall. The areas where this is most likely to occur is below windows and where rainwater drains off of a roof, and runs down the stucco wall.
Recommended, Dependable Stucco Repairs
- The loose, separated stucco should be removed
- Metal lath or a clean, porous masonry surface is necessary for proper adhesion of the new stucco. Metal lath should be “self furring galvanized steel,” and should be installed right side up. This will allow the stucco to key properly around the metal lath.
- The stucco mix should not be too rich because it will crack easily (too much cement).
- The stucco mix should not be too weak because the surface will be sandy and the adhesion qualities will be suspect (too much sand or water).
- If you have difficulty getting the stucco to adhere, such as on a ceiling, lime can be added to the mix.
- The proper mix is one part cement, three or four parts sand and just enough water to get the sand and cement to mix. This will vary based on the moisture that is already in the sand. 1/2 part lime will improve adhesion.
- The color and texture of stucco repairs are very difficult to match. Painting the wall after a reasonably close match of the texture should be satisfactory in most cases. Use of an elastomeric paint is recommended for this purpose.
- Cost of repairs are subject to the amount of repairs needed, the age of the stucco and the difficulty of the job. The range should start at a minimum of $300 for anything up to about 50 SF, plus about $5 per SF for the next 300 SF. As the amount of repairs increases, the SF cost should stabilize or decrease a little. New stucco should cost approximately $3.50 to $4.00 per SF.
Assuming a good mix and workmanship, stucco is relatively stable for about 20 years with no more than discoloration along the base and at windows. After 20 to 25 years, the stucco may begin to absorb moisture. The moisture, especially if it freezes, will break down the surface, and by the time it is 50 to 60 years old, it may require replacement. The best way to determine the condition of stucco is to rub a gloved hand along the stucco to see how much sand falls off the wall. The quantities should be minimal. If sand cascades off of the wall, it is evidence of considerable deterioration.
The typical life expectancy for unpainted stucco is about 50 to 60 years, assuming it is mixed and installed properly, and dependent on its exposure to weather and the sun. If stucco is painted periodically, it can last 200 years or more.
Cement Asbestos Siding
Cement asbestos siding is a composition of Portland cement, sand and asbestos. The asbestos is a mineral that comprises about 5% to 10% of this siding product, and is used as a binder because the cement is so fragile at this thickness. This siding is fireproof and relatively brittle. Cracking and breakage is fairly common. In many states, asbestos is considered a hazardous material when it can become airborne or friable. Friable asbestos fibers are easy to inhale. The human body has the ability to discharge larger asbestos particles, however, the particles that are only visible with a 400-power, photo sensitive microscope are not likely to be discharged from the body, but become lodged in the lungs. Depending on the person and the amount of exposure, health problems may develop—Asbestosis or Mesathelioma being the worst problems. Since residential building products have not been manufactured since 1973 and not installed since 1978, most of the asbestos-containing cement siding is older and may typically exhibit some cracking and breakage.
- Check for cracked, broken pieces, especially along the bottom of the wall.
- Check to make sure that the nails are not coming loose. When the siding was most popular, the sheathing of choice was 1/2 inch building board, such as Celotex. This material was okay for aluminum siding and wood sidings, because the sidings were nailed to the wall studs. Cement-asbestos siding was never on a 16 inch nailing pattern, so 3/8 inch thick nailing strips were nailed horizontally across the wall studs to receive the siding nails. If plywood sheathing were used, you could nail this siding anyplace. Look for the nailing strips at the bottom of each course. They should look like a reveal or shadow line. If they are not present, check to see if the siding was nailed to plywood. If neither is present, the siding is either loose or the paint is holding it on.
- Check for felt paper backer strips behind every vertical butt joint to deflect rain that gets behind these joints. A good place to look for problems is at the sill plates on the inside of the basement or crawl space. If they are wet or stained, this may be the cause, especially on the west side of the house, since that is where the prevailing weather comes from.
- Check that the bottom of the siding is well above the grade.
- Research your local regulations to determine whether or not handling cement asbestos siding is considered a hazardous waste in your area.
Aluminum and Vinyl Siding
Aluminum siding is almost a maintenance-free product, requiring only occasional washing down with a garden hose to keep the house looking good. Vinyl siding has many of the same features as aluminum siding. Both materials, when installed, are nailed/hung on sheathing that is covered with felt paper. By hung, we mean that the nails are not driven firmly into the sheathing, they are just driven until the siding is at the wall and straight. The main reason that they are hung on the wall is to give them room to expand and contract. Vinyl siding expands and contracts more than aluminum siding. You can see how much aluminum moves if you are inspecting the siding when it is in contraction (cooler times of the year or evenings). You may see the paint scratched at some of the vertical joints. Vinyl siding should move freely from side to side after installation. You should be able to move it with relative ease.
- Look for loose pieces of siding. They could be anywhere. High winds may cause pieces to come loose. Repairing/securing a small amount of the siding is relatively easy.
- Look for dents or damage that may have been caused by lawn mowers, baseballs or golf balls, etc. If pieces have to be replaced, the paint color is not likely to match.
- Check the plane of the wall for inflections, bows or other irregularities that may indicate another type of problem. The siding may loosen and buckle at the 1st or 2nd floor band joist due to lumber shrinkage, with the 2nd floor being the most common area.
- Check the installation. It should have room to expand at the windows, etc. Caulk is not necessary if the siding was installed with the proper “J” channels and corner posts etc. at windows, doors, chimneys, corners, top and at Soffits etc.
- Check the condition of the paint on the siding. The paint starts to chalk after 6 or 7 years with inexpensive siding; it may take 12 to 14 years with a better siding. If the paint is chalking and dull, it can be cleaned/power-washed and repainted.
Wood sidings come in the form of shingles, shakes, plywood, panels, boards (applied vertically and horizontally), and hardboard. The siding is generally available in cedar, spruce, firs, redwood, and hemlock, as well as pines and other soft woods. Other kinds of wood may be used in thin veneers on the exterior of the panels or plywood siding. Wood siding is prone to insect attack and water damage, so it should be closely evaluated where the wood is in close or direct contact with the soil. Areas where vegetation overgrowth has occurred are especially susceptible to deterioration and mildew/molds. Use a screwdriver to probe for suspected areas for deterioration or infestation. Areas where the soil is in contact with the wood components should be regraded so that a reasonable amount of space is available between the bottom of the wood and the soil or graded surface.
Inspect the wood for peeling or blistering paint; warped, split or cracked shingles; delaminated plywood; dark stains; or mildew and buckled boards. These problems typically indicate water damage or deferred maintenance. The sources of the water penetration may be from open seams or improperly sealed joints in the siding and trim; separations at the outside corners; missing or damaged caulk in these areas; loose and missing pieces or sections; or rusty nails and holes.
When inspecting the siding, you should also inspect the eaves, fascias, soffits and other outside trims. Closed soffits may pull loose, or birds, squirrels and insects may be able to access this area for nesting. Faulty guttering can also cause water damage and deterioration in the soffits. Suspicious areas should be probed with an ice pick, pocketknife or screw driver blade.
Some of the more popular styles of wood sidings:
Clap board is an overlapping wood material. The boards are typically installed horizontally. It is generally a good material, but should be painted and properly sealed. Older siding had a 3/4 inch butt edge; modern sidings could be 7/16 inch or as little 5/16 inch These modern sidings are susceptible to considerable cracking/splitting in 2 to 6 years.
Hardboard is a material that has been used for a number of years, and it should be kept painted and sealed at all times. Hardboard material can follow any form from basically a cardboard type composition to the modern day pressed wood or particleboard sidings. When this type of material is not properly maintained, it deteriorates rapidly. Hardboard, whether a cardboard variety, pressed board or particle board, should be probed in suspect areas, to ensure that the material is sound. Manufacturer recommended installation details and clearances should also be inspected for compliance.
Plywood has been used for quite some time as an exterior siding. Originally, it was only used on the gable ends of the residence. Since the early 1980s, it was relatively common to use plywood on most or the entire house. The most common of the plywood sidings is T1-11. It is typically fir or cedar, 7/16 inch thick, and has vertical grooves. All plywood used on the exterior should be painted or sealed to prevent delaminations. When the wall to be sided is taller than 8 inches, the plywood will have a horizontal butt joint that needs protection. A “Z” flashing should be used to protect the top edge of the lower sheet. Both of these edges should be painted before the sheets are installed.
Tongue and groove siding is very similar to clapboard, except that its tongue and groove design allows it to interlock, and it is installed vertically. It should not be installed horizontally or on a 45-degree angle. Check for water stains above sliding glass doors and windows that have draperies. This siding needs protection with a preservative stain or paint.
Evaluating Exterior Finishes
- Evaluation of the house to ensure that the walls are visually plumb and level.
- Evaluation to ensure that the siding is properly attached to the structure.
- Inspection for any areas on the exterior where the siding or masonry surfaces are missing.
- Evaluation of the structure where moisture might penetrate the building envelope due to splits, warping or separations.
- Evaluation of the exterior painted surfaces for signs of mold, peeling or cracking.
- Evaluation of the exterior masonry systems and mortar joints to ensure that they are in good condition, that weep holes are present and not below grade.
- Evaluation of the exterior masonry surfaces for cracks that are diagonal and break through the material instead of following the mortar joints, exhibit differential movement, such as sheer or bowing.
- Evaluation of the window and door lentils to ensure they have sufficient bearing on the sides, and do not exhibit cracking caused by expanding steel.
- Evaluation of the exterior surfaces for visible cracks and movement.
- Evaluation of the exterior surfaces for cracks or separations that in which water could penetrate and enter the wood substrate.
- Evaluation of all exterior surfaces for off-color patches, suggesting moisture penetration.
- Evaluation of all the doors and windows for operation. Do the doors and windows open, close and lock satisfactorily?
- Evaluation of all exterior window and door areas for weatherstripping.
- Evaluation of all windows for loose fitting or drafty conditions or broken glass.
- Evaluation of the windows for needed replacement or immediate repair.
- Wood siding: Loose, missing, displaced, cracked, deteriorated, insect damage, paint peeling, mold
- Shingles & Shakes: Split, warped, loose, broken, deteriorated, mold or insect damage
- Plywood: Delaminated, loose, worn, deteriorated, mold or insect damage, missing flashing
- Composition Board: Disintegrating, deteriorating, swollen, loose, not painted, mold
- Cement Asbestos: Displaced, cracked, broken, missing, no backer strips behind the joints.
- Aluminum/Vinyl Siding: Loose, missing, scratched or dented, cracked or damaged, molding loose or missing, caulking joints deteriorated or missing, surface worn.
- Brick/Stone/Block: Cracks, differential movement, loose, bowed, mortar missing or disintegrating, settled, no weep holes, detached from wall
- Conventional Stucco: Cracks, bulges, detached from wall surface worn or deteriorated, stained
- Trim/Soffits/Fascia: Deterioration, water damage, insect damage, loose, stained, missing section, peeling paint.