The cost of exterior siding work can command great interest but seem like something very basic that anyone can learn to install using a brake and a nail gun. This huge disparity in the quality of siding installers’ work creates blind spots where water can suddenly appear behind the siding.
For contractors, estimators and others involved in the exterior work of home improvement (siding, roofing, deck building) the key checks to verify a home-improvement contractor’s competence and separate them from other home-improvement contractors are the most important.
Verify Credentials against the Work, not the Company Name
The license number on the side of the truck looks real but read carefully. The state, even the city, issues Home Improvement Contractor or Specialty Contractor licenses. Even though siding work makes up the majority of a home improvement contractor’s work, he may be licensed as a Home Improvement Contractor and not a Siding Specialist. Make sure the class of license under which he is operating allows for the scope of work described for the proposed job.
Just as verifying a contractor’s license is important, verifying a contractor’s insurance is equally important. Request the exterior contractor provide a Certificate of Insurance that lists your name as the Certificate Holder. Verify that the general liability insurance and workers’ compensation insurance are current. If the exterior contractor is hiring subcontractors to complete the exterior work of your home, request verification of current insurance for each subcontractor as well.
What to request before any deposit changes hands
- A license number verified directly through the state board, not a copy supplied by the contractor
- A current certificate of insurance issued by the carrier
- Manufacturer certification documents, where the warranty depends on them
- Written confirmation of who will physically be on site, employees or subs
Separate Years in Business from Relevant Installation Volume
Experience does not necessarily translate to better work, and a roofer for 20 years with only occasional siding work is likely to provide substandard fiber cement siding work. Ask the number of jobs the exterior contractor’s crew completed in the past 12 months installing the same type of material (siding) on the same type of substrate (wall).
Important factors for successful siding work are region-specific details regarding wind load, freeze/thaw and high humidity issues. Siding installers from outside the region mostly fall back on their “installed practices” which most likely are not suited for your region’s climate. Homeowners in the Lehigh Valley, for instance, are better served hiring a siding company in Allentown Pennsylvania that installs through local winters every year. Ask for local job references and describe how they handle typical details such as siding to roof, siding to chimney, flashing, water management, etc. On typical homes in your region.
Judge Workmanship by the Details nobody Photographs
One of the best ways to look at completed work is the prep work that goes into completing that work. Ask for the following indicators of quality work.
Questions that reveal installation standards
- How is the weather-resistive barrier lapped and integrated with window flashing?
- What fastener type, length, and spacing will be used, and does it match the manufacturer’s published schedule?
- How are butt joints handled, and are joint flashings installed behind them?
- What is the plan if rotted sheathing is discovered, and how is that priced?
- How are penetrations for vents, hose bibs, and electrical boxes sealed?
A good estimator can explain to you a job that you have asked for, and give you reasons for the decisions that he has made on your job. His vagueness is probably the best predictor of future failures.
Read the Two Warranties as Separate Documents
The warranty provided by a manufacturer for siding materials and the warranty provided by a Home Improvement Contractor for the workmanship and materials used in the installation of that siding can be very different. How a contractor handles failures of both can vary greatly.
| Factor | Material warranty | Workmanship warranty |
| Issued by | Manufacturer | Installing contractor |
| Typical term | 25 years to limited lifetime | 1 to 25 years, widely variable |
| Covers | Cracking, fading, delamination | Improper fastening, flashing, water intrusion |
| Voided by | Non-compliant installation | Contractor ceasing operations |
| Transferable | Often, with conditions and fees | Rarely |
A long material warranty with a less than adequate labor warranty (less than 3 years) generally indicates that the siding material seller is more of a material peddler than a quality siding installer. Installation failures generally surface within 3-7 years from installation and the siding manufacturer will blame the poor installation by the siding contractor.
Treat Material Recommendations and Communication as Diagnostic
Another red flag for “siding salesmen” would be that they only recommend one type of siding for every house. The different types of siding have different characteristics such as expansion, cost, and amount of maintenance. Therefore, a good siding advisor would recommend the best type of siding for a customer’s specific wall assembly and budget. This could include vinyl, engineered wood, fiber cement, or metal siding.
Communication prior to the commencement of work on your home and after the start of work on your home is of extreme importance and will typically follow accordingly. If prior to the start of work on your home the exterior contractor has a very good process for handling change orders, questions, etc. Then expect the same communication after work has started on your home. Would the exterior contractor of your choice have a clear point of contact, return your phone calls in a timely manner and return all of your emails in a timely manner? Also, how does the exterior contractor pay his subcontractors? By completion of work on specific sections of your home or by a pre-determined date on the calendar?
