What’s the difference between a hot roof and a cold roof?
In a cold roof, the insulation is applied between the rafters, but in a warm roof, the insulation is applied on top of the existing roof surface.
Which type of insulation is best for attic?
Many people consider fiberglass batt to be the best attic insulation. It consists of plastic reinforced by small glass fibers. The batt version comes in blanket form — i.e., small, pre-cut sections that you can lay down wherever you need to.
What is the most efficient roof insulation?
One of the most common and effective ways to insulate your roof is with polyurethane spray foam. This spray-applied plastic is known to be highly effective for sealing any cracks as well as resisting wind and heat. The foam is applied to the underside of your roof deck and directly onto the slates and tiles.
Does cold roof need ventilation?
Cold Roofs
A cold roof is where all of the insulation is placed either between and under or completely under the joists or deck. No insulation is on top. In this way the roof itself is kept cold. You only need ventilation in a cold roof.
Does a cold roof need a vapour barrier?
You don’t need a vapour barrier in cold roof systems as that’s exactly what the ventilation is for, it acts to disperse any moisture.
How thick should the insulation be in an attic?
about 10 to 14 inches
R-Value is a measure of insulation’s ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
Can you over insulate your attic?
It’s possible to over-insulate an attic as too much will cause moisture buildup and eventually result in mold. Eventually, adding more insulation leads to diminishing returns in trapping heat as well.
Do you insulate the roof in an attic?
Proper attic insulation can also keep your roof in better condition by helping to prevent ice dams and condensation. Your building codes may require you to have a certain quality of insulation. However, installing even better insulation is to your advantage and your roof’s advantage.
Does a hot roof need ventilation?
A “hot roof” means that insulation is installed closely beneath the roof decking, without space for ventilation. In some cases, this design allows the attic space to be usable like any other room in the house by bringing it into the thermal envelope of the home.
Do you need an air gap for insulation?
Insulation is technically a solid with a lot of air in it therefore, it is NOT an air gap. You literally must have a VOID, nothing in the air gap except air itself. So if you are installing under a roof or in a wall, you must create an air gap.
What happens if a roof is not vented?
Unventilated or poorly ventilated attics don’t have an escape route for the heat that builds up. This buildup of heat can damage your shingles from the inside out. An evenly vented roof will allow the hot air to escape keeping your roof and attic cooler.
How do you tell if attic is properly vented?
How to determine whether you need better attic ventilation
- Look at your eaves and roof. …
- Touch your ceiling on a warm, sunny day. …
- Thick ridges of ice on your eaves in winter are a sign of poor attic ventilation. …
- Warm air that escapes living space also carries moisture that will condense on rafters or roof sheathing.
What is the best way to vent an attic?
5 TIPS FOR IMPROVING YOUR ATTIC VENTILATION
- Assess Your Needs. Before you make any changes, it’s important to determine if your attic actually needs additional ventilation, and if so, how much. …
- Insert Roof Vents. …
- Add Soffit Vents. …
- Install Gable Vents. …
- Use Fans to Improve Airflow.
Is attic fan necessary?
Attic fans do really work. They will help to circulate air in your attic and ventilate the space so that it stays closer to the outside temperature. Attics can reach extremely high temperatures in hot, summer months and gather an excessive amount of moisture in the winter. Attic fans will help fight these problems.
Should I turn off my attic fan in the winter?
Q: Should I turn off my attic power fan and close the vents during winter? A: Although the natural instinct to keep the house warmer may be to close the attic vents, that is definitely not a good idea. In fact a cold, drafty attic is the ideal condition for an attic during winter.
How can I keep my attic cool in the summer?
Best Way to Cool an Attic
- Install an Air Conditioning Unit. …
- Seal the Cracks and Gaps. …
- Upgrade the Insulation. …
- Add Ventilation for Improved Circulation. …
- Install Radiant Barriers. …
- Install an Attic Fan. …
- Add Reflective Roofing.
Do you still need an attic fan when you have a ridge vent?
Combining an attic power vent fan with a ridge vent is usually not recommended because: It could reverse the natural flow of hot air out the ridge vent. If air is drawn in through the ridge vent while it’s raining, it might pull rainwater in with it, which could lead to leaking or mold in the attic.
Is it better to have a ridge vent or attic fan?
Ridge vents are much cheaper and more durable than attic fans. They’re more cost and energy-efficient. But they can’t ensure proper ventilation always. Hence, for larger and congested spaces, an attic fan is the best option.
Which is better ridge vent or power vent?
While a power vent fan combined with a ridge vent can work against the natural flow of air through the attic, it will still exhaust more hot air than not having a fan at all, it’s just not the most efficient way to go about it.
