Siding appears to fail suddenly but it actually degrades slowly over time and fails all at once. Visible signs of siding failure, like cracks in individual panels or sections of peeling paint, signify the end of a long degeneration process that occurred behind the siding for years. The important thing is to be able to differentiate between early warning signs of potential expensive repair and cosmetic issues that need to be addressed only once.
Build an inspection routine that finds water, not just damage
Inspect your exterior siding twice a year, once in the early spring after the last round of freeze-thaw cycles and again in late fall before heating up for the winter. Walk around the entire exterior of your house at ground level and then inspect the upper parts of exterior walls and gable ends from a ladder or with binoculars. Most owners only get to inspect areas that are easily accessible. Yet that is often where there is the least likelihood of siding failure.
The majority of water entry occurs at the penetrating items, terminations and change of plane in the siding. Thus a single soft spot in the paint at the trim is a localized leak and can be repaired with siding patches.
- Window and door heads, where flashing may have been omitted or reverse-lapped
- The bottom course and starter strip, checking for a clear drainage path and no soil contact
- Roof-to-wall junctions, especially kickout flashing at the eave edge
- Dryer vents, hose bibs, electrical penetrations, and light block mounts
- Inside and outside corners, where panel movement concentrates
Read the pattern, not the single defect
A single spot of looseness in trim, flashing, etc., could be a local problem and could be repaired. A vertical line of staining, peeling paint, etc., down from a single point indicates that water has penetrated and is traveling in concealed pathways within the wall and may require opening up of the wall to repair. Even staining that has spread evenly across a wall face could indicate splash back from roof downspouts, sided sprinklers, etc. Or that a gutter has been installed to overhang the side of the house.
Understand where sealant belongs and where it causes harm
The caulk which was attached to the exterior trim of your house is a wear item and will last for significantly less time than the siding it is meant to protect. Because of this, failed sealant at vertical joints in trim is typically an easy fix with a quality polyurethane or hybrid caulk once the old bead of caulk has been removed in its entirety.
Too many building owners want to caulk seams that are intentionally open to let water down to the foundation. These are weep holes for vinyl siding, bottom of lower course of fiber cement, and under sill pans for windows. Closing these up will trap moisture between the siding and sheathing and promote early decay of sheathing materials. Most leaks at seams are simple flashing problems that call for repair of the faulty flashing rather than more caulk, and local homeowners are usually better off having a crew that specializes in siding services in Charlotte rebuild that detail correctly.
Specify the right product for the substrate
Most sealants are best suited for painting over after installation. Some must be compatible with certain types of sheathing. Paintable acrylic latex caulks are generally the best for trim that will be painted. High-movement joints between two different materials are typically best served by specific types of caulks. The joint must be sized to allow for the expected amount of movement and allow for contraction and expansion of the sealant itself.
Distinguish fading, chalking, and real coating failure
Uniform fading (graying) of surfaces exposed to the elements on a south or west exposure is normal. Chalking or ‘dusting’ of siding surfaces is a surface condition where the surface of the paint or coating has broken down to form a powder that rubs off with your hand. On vinyl siding this can be ‘cleansed’ with specialized cleaners, but heavily chalked surfaces may not be receptive to the application of a siding coating for restoration purposes.
Paying particular attention to siding made of painted wood or fiber cement, peeling which exposes the underlying surface is indicative of moisture moving outward from behind the siding and does not necessarily mean it is time to paint again. Generally such a surface can be coated again within two years.
Plan for color mismatch before you repair
This siding is getting old. You can be sure that no replacement panels will ever exactly match your now aged siding. Although most siding manufacturers will carry older stock in the attics of buildings for years to come, they eventually are retired and most colors are eventually phased out by most manufacturers. Thus, the best solution is to move older siding from an out of the way location such as the attic to the area where you need it for repair and then cover it up with new siding.
Catch warping and movement problems early
Water expandable siding such as vinyl must be installed in such a manner that it has sufficient room to expand and contract in hot and cold weather. That means nails must be placed near the center of the vinyl panel’s slot and driven into the siding only enough to allow about 1/16 inch of siding’s natural expansion and contraction. This will prevent vinyl siding from sagging or becoming deformed in hot weather. Buckling siding is a common problem with face-nailed vinyl siding and with siding that has been over-driven with nails.
Note that localized melting of siding near a grill, low-e window, etc. Is not a problem that will be cured by replacing siding again and again. Siding can be protected by shielding, etc. And/or by replacing panels of siding with new ones.
| Material | Primary failure mode | Cleaning interval | Typical recoat or refresh |
| Vinyl | Buckling, cracking in cold impact | Annual, low-pressure wash | None, replace sections |
| Fiber cement | Edge swelling, paint failure | Annual | 10 to 15 years |
| Engineered wood | Moisture wicking at cut ends | Annual, inspect cuts | 8 to 12 years |
| Cedar | Cupping, splitting, rot | Twice yearly | 3 to 7 years, stain dependent |
Know when repair stops making sense
It stands to reason that even moderate numbers of repairs can exceed the cost of completely re-siding an elevation. Furthermore, most local siding contractors will quote costs to re-side as well as to repair the siding on a given elevation. Be sure to include an estimate for any required repair to the sheathing as well.
Take before and after photos of all parts of the wall from the same fixed points each time you inspect. It’s much easier to see changes over time when you have photos rather than trying to remember.