Some common types of insulation used for roof rafters include fiberglass batts or blanket insulation, cellulose, and spray foam. Fiberglass batts are one of the most affordable options and offer decent resistance to heat flow with an R-value between 3.2 and 4.3 per inch, depending on where they are being installed.
Cheapest way to insulate is to get your drywall up and then spray loose insulation in the rafters until you reach the specified depth. Usually you can get a machine rental with the purchase of 20 bags. Takes two people but it's easy and cheap (~$500) for my area.
Rigid foam boards such as PIR, XPS or EPS are one of the best roof insulation materials for this insulation method. They offer excellent thermal efficiency, warming the entire loft and are easy to install in difficult roof areas..
Common materials used in flat roof insulation include polyisocyanurate (PIR) boards, expanded polystyrene (EPS), extruded polystyrene (XPS), mineral wool, and spray foam. Additionally, materials such as PIR and EPS are cost-effective, contributing to the overall low cost of roof insulation for flat roofs.
Insulating between rafters can help to improve the energy efficiency of your home or building by reducing heat loss through the roof. This can lead to lower energy bills and a more comfortable living or working environment.
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.
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.
For example, cellulose insulation, made from recycled paper, is a popular, cost-effective, and high-performance option. But if you're leaning towards natural materials and have a higher budget, sheep's wool or hemp insulation can be appealing options that offer excellent thermal properties and humidity regulation.
To insulate an existing flat roof from the inside, first, inspect the loft for any damage that may need repair. Next, install a vapour barrier to prevent moisture build up. Then, measure and fit the insulation material between the loft joists, starting at the eaves and leaving a 25mm gap for ventilation.
Different Materials for Roof Rafters
They are commonly made of dimensional lumber or engineered wood products. Wood rafters are suitable for most residential and light commercial applications and are often preferred for their aesthetic appeal.
Cellulose blown-in ceiling insulation is a good choice for DIYers. It has a higher R-rating and is less expensive than blown insulation like fiberglass attic insulation or fiberglass batts. Blown-in cellulose is an environmentally friendly material made from recycled newspaper, so it's easier on your skin and lungs.
Blanket or batt insulation tends to be among the affordable options, typically ranging from $0.50 to $1.50 per square foot. Conversely, when we shift focus to foam board or spray foam insulation, it can cost anywhere between $1.00 and $3.00 per square foot.
Overall, fibreglass insulation is the cheapest and most effective insulation option available, making it a popular choice for homeowners and builders alike.
It's important to leave a ventilated air gap between the insulation and the boards to prevent condensation on the underside of the boards.
If the insulation is installed properly, there should be a 2" air space above the insulation to the sheathing. In all practical purposes, this is should be easy to do if the rafters are 10" deep and the insulation is only 8". If that is the case, the random touching of the insulation buckling up will not matter.
Roof and ceiling insulation. Installing roof and ceiling insulation can save up to 45% (or more) on heating and cooling costs.
Polystyrene insulation is simple to install and can be cut to any size or form, making it an excellent choice for do-it-yourself applications. They are cost-effective and help prevent warm air from losing heat.
Best Time of Year to Buy Insulation
In this case, the spring is the best time, because you will also start to see savings in the summer months. The same is true for warmer climates, just different times of year because you'll want the job finished before the heat sets in.
You can choose from different materials like cellulose (made from recycled paper), fiberglass, or mineral wool. Cellulose is an eco-friendly and cost-effective insulation for attics. Fiberglass and mineral wool are also popular choices because they are good at keeping heat in or out and resist moisture and pests.
ROCKWOOL rafter insulation offers maximum thermal and acoustic benefits as well as superior fire safety, helping you to create a comfortable living environment within your roof space. The natural power of stone wool means that our insulation will last for the lifetime2 of your building, without any sagging or slumping.
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.
You could use either three layers of 2" rigid which would give you approximately R-30 or use one layer of of 4" and another of 2" which will give you the same R-valve. Foam insulation is very messy to work with and bad for the lungs. Other than that, spray foam could be another option.