Compare the highest-rated insulation professionals in Johns Island, South Carolina. All contractors are licensed, insured, and verified through our rigorous screening process.
A leading provider of comprehensive insulation and air sealing solutions for the South Carolina Lowcountry. They are known for their expertise in both new construction and retrofit projects, with a strong focus on improving home energy efficiency and comfort in the local climate. They are often recommended for their professional crews and detailed energy audits.
Serving the entire Charleston tri-county area, Holy City Insulation has built a strong reputation for reliability and quality workmanship. They offer a wide range of insulation types and are particularly skilled in handling complex attic insulation and crawl space encapsulation projects common to the coastal region.
While based in North Charleston, this company is a top-tier service provider for Johns Island and specializes in creating energy-efficient building envelopes. They are certified installers for major insulation brands and are well-versed in local building codes and available utility rebates, helping homeowners maximize their investment.
The insulation market in Johns Island is characterized by a moderate level of competition, primarily from established Charleston-area contractors who extend their services to the island. The quality of service is generally high, as these companies must compete for business in a discerning market that includes both historic home renovations and new, high-performance custom builds. The unique coastal climate—with high humidity, hot summers, and the potential for storm-driven moisture—demands expertise in vapor barriers, moisture management, and air sealing, which the top-tier providers all emphasize. Typical pricing is in line with Southeastern averages but can be on the higher end for premium services like full attic foam encapsulation or crawl space conditioning. For standard blown-in fiberglass attic insulation, homeowners can expect a range of $1,500 - $3,500, while spray foam projects and complex crawl space encapsulations can range from $5,000 to $15,000+ depending on the scope and square footage. Energy audits are a common and recommended first step, typically costing $300-$600, and can often be applied as a credit toward subsequent insulation work.
4.7+ star average from verified customer reviews
All contractors are properly licensed and insured
10+ years average experience in the industry
Familiar with Johns Island regulations and climate
Get answers to common questions about insulation services in Johns Island, South Carolina.
For our coastal Lowcountry climate, spray foam insulation is often the top recommendation because it provides an excellent air seal, which is critical for managing humidity and preventing mold growth. However, blown-in cellulose or fiberglass in attics is also very effective and cost-efficient for Johns Island homes, especially when paired with proper attic ventilation to combat our intense summer heat. The best choice depends on your home's construction, your budget, and specific moisture concerns.
Attic insulation costs in Johns Island vary based on material and the square footage to be covered, but homeowners can generally expect to invest between $1,500 and $4,500 for a professional job on a typical single-family home. Regional material costs and the higher performance standards needed for our climate influence pricing. It's crucial to get multiple quotes from local, licensed contractors who can assess your home's specific needs, such as adding a radiant barrier to reflect the strong South Carolina sun.
The ideal times are during our milder fall (October-November) and spring (March-April) seasons. This avoids the peak summer heat and humidity, which can make attic work unbearable for crews and affect the curing of some materials like spray foam. Scheduling in these off-peak windows also often leads to better availability from reputable local contractors before the busy pre-summer rush.
Yes, Johns Island follows the South Carolina Residential Building Code, which includes specific requirements for insulation R-values (the measure of thermal resistance) for our climate zone. For example, attic insulation in our zone should meet or exceed R-38. Additionally, due to our high humidity and hurricane risk, proper air sealing and moisture barriers are critical and are often emphasized by local inspectors to prevent structural damage and mold.
Absolutely. Many historic and older homes in Johns Island were built with little to no insulation, leading to significant energy loss and discomfort. Adding insulation—particularly in the attic, crawl space, and walls—is one of the most effective ways to reduce your cooling costs, which are a major expense given our long, hot summers. It also improves indoor air quality by reducing humidity infiltration and makes your home more comfortable year-round.