Radiant barriers are highly effective at reflecting heat in hot climates, but they come with notable drawbacks. Major problems include trapped moisture and mold risk, dust accumulation that ruins reflectivity, interference with cell signals, conductivity risks around electrical wiring, and high installation costs that may not pay off.
Aluminum covered radiant barrier products (like Original AtticFoil™) are pretty difficult to start burning, but once they flash (catch fire) the polyethylene scrim inside will continue to burn at a relatively slow rate.
Neither is inherently better; they serve entirely different purposes. Traditional insulation (like fiberglass or cellulose) slows down the transfer of heat. Radiant barriers (reflective foil) reflect radiant heat away. In hot, sunny climates, a radiant barrier reduces cooling costs significantly, but it cannot replace thermal insulation.
No, radiant barriers do not damage roof shingles.
Lay the radiant barrier foil loosely over the attic insulation. Do not press it into the insulation. Your insulation will have some peaks and valleys, which is fine. Ideally you want about 10-20% surface contact with the foil.
Yes, a radiant barrier absolutely needs an air gap to function. Because it works by reflecting radiant heat, it requires an empty space (void) for the heat waves to travel through. If the barrier touches another material directly, the heat transfers via conduction and the reflective properties are lost.
Choosing between a radiant barrier and spray foam depends on your budget, climate, and primary goals. Radiant barriers reflect radiant heat to lower attic temperatures in hot, sunny climates. Spray foam provides total air sealing and insulation, excelling at reducing energy loss and drafts in all seasons.
To tell if a roofer is lying, watch out for high-pressure sales, suspiciously low bids, and demands for large upfront cash payments. Honest roofers provide clear, detailed contracts and verifiable credentials. Always check their local license, avoid signing contingency agreements before fully committing, and get a second opinion.
Because spray foam can trap moisture, hide the condition of the roof, make it difficult for surveyors to inspect, which means risks like timber decay, dry rot, and not forgetting increased fire risk. If you've got it or you're buying a property that does, this is something you need to know upfront.
Most contractors use blown-in, loose fill insulation for attic floors, which is quick and easy to install with the right equipment. Typical materials include fiberglass or cellulose – both contain some recycled content (glass or ground up paper) and are inexpensive and safe.
The best radiant barrier depends on your installation method and climate, but commercial-grade, heavy-duty woven radiant barriers are highly rated for DIY and professional use. The industry standard is a double-sided, perforated, and tear-resistant aluminum foil that blocks up to 97% of radiant heat.
Mice are curious and always searching for safe, snug, and warm nesting sites. Attics filled with blown-in insulation provide an excellent option–from the mice's point of view. As long as there is a ready food source. Mice are omnivorous and will eat and chew on almost anything including wood and electrical wires.
Potential problems with spray foam insulation
reduce air circulation and ventilation within a roof space. lead to dampness and condensation on the underside of a roof because it forms an air barrier and stops moisture from escaping. place timber-framed roofs at risk of decay.
Continuous insulation on the exterior side of wall framing is increasingly required in colder climate zones. This addresses thermal bridging through wood or steel studs, which can reduce the effective R-value of a wall assembly by 20% or more.
Radiant heating systems, while offering comfortable and efficient warmth, have significant disadvantages, most notably high installation costs, difficult retrofitting in older homes, and slow response times. They generally cannot be used for cooling, and repairs can be highly invasive if leaks or electrical issues occur beneath the flooring.
This might surprise you, but radiant barrier foil on its own has virtually no R-Value! This is important to understand because radiant barrier does not take the place of traditional insulation (fiberglass, cellulose, etc.).
The healthiest, non-toxic insulation for your home is natural sheep's wool or hemp insulation. These materials contain no chemical binders or formaldehyde, actively regulate indoor humidity to prevent mold, and do not off-gas.
Foam insulation is a common target because it's easy for them to chew through. The material offers little resistance, allowing mice to create tunnels or nests within the insulation. But mice aren't just interested in chewing for the sake of it—they're also drawn to the warmth and shelter insulation provides.
The chemical aspect of spray foam makes it very hard for standard insurance companies to provide coverage. Most standard lines insurance carriers want to write the risks with no liability not spray foam contractors that manufacture plastic every day in the field.
What Should You Not Say to a Contractor?
So, can a roofer sue you if they fall off your roof? In most cases, no—especially when the roofing company is insured and the homeowner hasn't contributed to unsafe conditions. The best protection comes from due diligence: hire qualified roofers, verify insurance, and communicate expectations clearly.
Here are a few techniques to determine if someone is telling the truth or not.
Ultimately, while spray polyurethane foam itself does not feed mold and mildew, results depend on how well the entire building envelope manages moisture. Preventing mold issues isn't just about choosing the right insulation material – it's about ensuring proper design, installation, and ongoing maintenance.
Insulating a house cheaply relies on simple, DIY-friendly fixes. Prioritize sealing air leaks with caulk and weatherstripping, applying clear Window Insulation Kits on drafty glass, using thick thermal curtains, and rolling budget-friendly Fiberglass Batts directly over sparse insulation in your attic.
Unfaced insulation is great for new construction, remodels, walls, floors, ceilings, basements, attics and crawlspaces. It's best used for interior wall applications that do not face the outside and also in rooms that don't need moisture control, like living rooms, dining rooms and studies.