The general advice we give is that you should always insulate between and above the rafters (warm roof) or between and under the rafters (cold roof).
To protect the roof from the potential of condensation occurring unseen within the construction, it's important to remember that the layer of insulation installed over the rafters should be equal or greater in thermal value than the layer between the rafters.
Yes, an air gap between the roof and insulation is needed, especially for traditional materials like fibreglass, mineral wool, and foil insulation.
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.
Insulation is ran vertically or horizontally from pole or post and attached directly to the girt. For horizontal installation it is optimal to have the edges of the two pieces of insulation to meet directly on the girt.
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.
If access is easy and your loft joists are regular, you can use rolls of mineral wool insulation. The first layer is laid between the joists – the horizontal beams that make up the floor of the loft – then another layer is laid at right angles to cover the joists and make the insulation up to the required depth.
Install the insulation: Install the insulation by placing it between the rafters and pressing it firmly into place. If using loose-fill insulation, use a blower to fill the cavity completely. Seal any gaps: Seal any gaps or spaces between the insulation and rafters with foam insulation sealant or caulking.
Where the distance from the top of the braced wall panel to the top of the rafters or roof trusses above is between 91/4 inches (235 mm) and 151/4 inches (387 mm), blocking between rafters or roof trusses shall be provided above the braced wall panel in accordance with Figure R602.
The thickness of insulation material between rafters is a crucial factor in achieving an optimal level of thermal performance. That's why the UK regulations state that the recommended thickness range should be between 170mm and 350mm.
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.
Depending on the specifics of the roof, it may be possible to fully fill the rafter depth or, in most cases, leave a 25mm or 50mm air gap between the top face of the insulation and the sarking membrane.
(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.)
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.
Our Conclusion. We recommend spray foam insulation because of its relatively simple installation process, high R-value, and applicability to different climate regions. While there are other effective insulators, contractors consistently choose spray foam for these reasons.
Staple the Multifoil to the underside of the Roof Rafters. We advise stapling every 300mm to ensure that the material is held securely in to place. Pull the material nice and straight where possible, to keep it neat and also to make the cutting process easier for you too.
Essentially, deck blocking, or joist blocking, is a critical STRUCTURAL element of building a deck.
Not always. The answer depends on the type of roof and vent space you have (vented or unvented) and how you want to insulate your attic space. But, if your home does require attic baffles, you simply can't skip this crucial material.
Roof rafters shall be spaced either 16 inches or 24 inches apart (on-center (o.c.). The roof design is based on a simple gable end roof with the ridge line at the center of the building width, or a sloped shed type.
When it comes to insulation, it's generally recommended to leave a gap between the insulation material and any other surfaces, such as walls, ceilings, or roofs. This gap provides ventilation and prevents moisture buildup, which can lead to mould and other problems.
Placing Insulation: Place the insulation between the rafters. For fiberglass batts, ensure the paper side faces down if you mainly heat your home. If you mainly cool your home, the paper side should face up. Pressing Firmly: Press the insulation firmly into place but avoid compressing it.
For narrower areas, cut the insulation to the required width and lay it between the joists in the same way. Don't pack or compress insulation into awkward corners.
Below are some additional considerations for insulating around a few common objects in the home. Wiring – When wiring exists in the cavities that are being insulated, simply split the insulation so that it is placed around the wire on both sides, allowing the wire to be comfortably nested inside the insulation.
The most popular approach is by fitting blanket-style insulation (mineral wool) in between and over your roof rafters, then securing these in place with netting before adding plasterboard to cover it up.
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.