When ventilating a roof to prevent condensation and moisture buildup, the recommended air gap between the roof sheathing (decking) and your insulation is typically 50 mm (2 inches). This gap allows fresh air to travel from the soffit vents at the bottom up to the ridge vents at the top.
Yes. For standard vented attics and cathedral ceilings, you must maintain an air gap of 1 to 2 inches between the top of the insulation and the underside of the roof sheathing. This void is vital for continuous airflow to prevent moisture buildup, mold, and rot.
In summary, whether you're using insulation boards or foil insulation, it's important to leave an air gap to improve the effectiveness of the insulation and prevent moisture buildup.
Specifically, it mentions that a minimum ventilation gap of 50 mm (2 inches) should be maintained between the insulation and the roofing membrane for pitched roofs.
Yes, you can insulate the underside of your roof, but doing so converts your attic from a vented "cold" space to an unvented "conditioned" space. This requires careful moisture control to prevent roof rot. You can accomplish this in two primary ways:
The 25% Rule in roofing serves as a guideline for both homeowners and contractors when planning roofing projects. Basically, it means that if more than 25% of your roof's surface needs repairs, it's often wiser to contemplate a full replacement rather than patchwork.
Tar paper serves several critical functions that shouldn't be overlooked: Waterproofing: In our experience, it acts as a secondary barrier against moisture, ensuring that any water sneaking past your shingles doesn't compromise the wood beneath.
Yes, you can put insulation directly against a roof, but only if you use the right materials and seal the roof deck properly to prevent trapped moisture, rot, and shingle damage.
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.
What time of year is Insulation cheapest?
Without a dishwasher air gap, contaminated water can flow back into the dishwasher. A dishwasher air gap prevents this from happening by ensuring that the water flows in one direction: out of the dishwasher and into the garbage disposal.
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.
This is where sizing comes in, and it varies depending on the material used and where it's installed. It's recommended to leave an air gap insulation of at least 25mm or 1 inch for the walls and ceilings. This should be enough to allow for ventilation and prevent moisture buildup.
Closed cell spray foam is rigid once set. It is a better thermal insulator and was previously sold to stabilise failing roofs. But if it has been used inappropriately or installed poorly, it might put stress on timbers, restrict air circulation and put them at risk of decaying.
Yes, but only if you are converting your attic into a conditioned, livable space. If your attic is purely for storage, you should never insulate the roof rafters. Instead, insulate the attic floor joists to keep your home’s main living space, and let the attic itself remain ventilated.
Insulating the underside of your roof is highly recommended if you are converting your attic into a living space or have HVAC equipment in the attic. However, for standard unused attics, it is much better and cheaper to insulate the attic floor instead.
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.
For most asphalt roofs, any temperature below 40°F (4°C) is generally too cold for installation. Below this threshold, materials lose flexibility and become brittle, increasing the risk of cracking and tearing during installation. Furthermore, the adhesive strips on the shingles rely on the sun's heat to properly seal down, which can fail in freezing conditions.
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.
Generally, the late fall and winter months can be the most cost-effective times to schedule a roof replacement. This is typically the slow season for roofing contractors, and as business wanes, you might find that they are more willing to negotiate on price.
For enhanced water-resistance and protection from the elements, many roofers are choosing to go the route of synthetic roofing underlayment. These products are usually made from long-lasting polymers, which provide added strength and longevity.
Neutral and timeless roof colors like black, charcoal, gray, and brown consistently deliver the highest return on investment. These classic shades have universal appeal, seamlessly match nearly all architectural styles, and attract the widest pool of potential buyers.
There are specific phrases that consistently cause problems. Saying “my roof was already damaged before the storm” gives the adjuster a reason to classify damage as pre-existing. Admitting fault with “I think it might be my fault” shifts liability onto you.
1/2-Inch Plywood: Commonly used for residential roofing with rafters spaced 16″ apart. It is acceptable under many codes but may flex under heavy snow or foot traffic. 5/8-Inch Plywood: Offers better support and is often preferred in areas with snow load or roofs supporting solar panels.