1. In unfinished attic spaces, insulate between and over the floor joists to seal off living spaces below. If the air distribution is in the attic space, then consider insulating the rafters to move the distribution into the conditioned space.
The easiest way to insulate your roof is beneath (rather than between) the rafters as you don't need to leave gaps for ventilation.
Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).
Yes, the insulation should completely cover the ceiling below or you'll have cold spots and mould in the room below. However, you must ensure ventilation to the eaves.
In addition to walls and attics, insulation should be installed in ceilings with unheated spaces, basement walls, floors above vented crawl spaces, cathedral ceilings, floors over unheated garages or porches, knee walls, and in between interior walls—especially bathrooms—as well as ceilings and floors.
Start laying the insulation furthest away from the access hole then work your way back from the outside edges in. Install the insulation between the ceiling joists and butt pieces together at all joins.
One of the less obvious but crucial benefits of insulating attic roof rafters is moisture control. Insulation helps prevent condensation, which can lead to mold and mildew. Mold is not only damaging to your home but also a health hazard.
It's important to leave a ventilated air gap between the insulation and the boards to prevent condensation on the underside of the boards.
You can put all the insulation on top of the roof deck, all the insulation on the underside of the roof deck, or some on top and some below. You can put it all below the roof deck but use two different kinds. Your insulated roof can be a cathedral ceiling or it can be above a conditioned attic.
Our Conclusion. We recommend spray foam insulation because of its relatively simple installation process, high R-value, and applicability to different climate regions.
Insulation is graded by its R-value—the higher the R-value, the greater the insulating power. If you live in a mild climate, your attic should have a minimum grade of R-38, or about 13–14 inches of insulation. If you live in a colder climate, R-49 is the minimum recommendation, or about 16–18 inches of insulation.
Never place insulation close to water heaters, oil burners or anything hot. The backing is especially flammable and will be a major fire hazard for your home.
In unfinished attic spaces, insulate between and over the floor joists to seal off living spaces below. If the air distribution is in the attic space, then consider insulating the rafters to move the distribution into the conditioned space.
Since insulation is not water-resistant, insulating your ceiling will give you better protection for your money. The insulation in your ceiling is less likely to suffer damage from unidentified leaks. When a roof leak develops, you'll find it more easily, which means you can have it repaired sooner.
No air space means no thermal value. The reflective side must be facing downwards when in roofs, upwards when installed underneath a floor and inwards when installed in walls.
For traditional pitched roofs, sometimes called sloping roofs, you will be looking at three main options to insulate from the inside; installing solid insulation boards between the joists of your roof, installing fibreglass or mineral wool insulation batts within the joists, or installing spray foam insulation on your ...
Yes, too much loft insulation can cause dampness in some situations. Loft insulation works by trapping warm air inside a building, preventing it from escaping through the roof. This helps to keep the interior of the building warmer in cold weather, reducing the need for heating and saving energy.
(Source: NRCA.) In the event you are erecting a “cold building” (such as a refrigeration building) that stays at 32 F (0 C) degrees or less inside, you will need a vapour barrier on the outside of the insultation to prevent warm exterior air from entering and potentially damaging the roof's insulation. (Source: NRCA.)
If you can get into the loft, measure the thickness of the insulation that's already there. Since 2003, current building regulations recommend a depth of at least 270mm (mineral or glass wool) in the loft – use this as a starting point rather than a finishing line to see larger savings.
As a general rule, insulation should be replaced or retrofitted every 15 to 20 years. However, it may need replacing or retrofitting sooner depending on the type of insulation installed, the R rating of the original insulation, compression and movement over time, and whether any damage has occurred.
Do you have any plans for furnishing/fitting out your attic in the future? Then you could simply insulate the pitched roof. But the best solution is actually to insulate both the attic floor and the underside of the roof.
So if you are insulating a pitched roof, we would recommend having insulation either above or below the rafters.
In roofs, the air gap should be larger, typically around 50mm (2 inches), to allow for proper ventilation and prevent condensation. It's important to note that some insulation materials, such as spray foam, do not require an air gap.