Insulation Between Attic Rafters

Common rafter depths range from 100mm to 200mm.

Insulation between attic rafters.

This generally would not be a sufficient thickness to achieve the u values required to meet building regulations and more insulation would need to be added. If you re considering turning your attic into conditioned storage or living space it s worth changing tactics to insulate between the rafters and wall joists instead of the floor. If your attic is going to be converted into livable space then you will need to insulate the roof rafters. This limits the maximum thickness of the insulation between the rafters to between 50mm and 175mm.

The will hold open an air gap of approximately 1 inch to allow airflow past a layer of insulation. Place the plastic sheeting on top of the rolled insulation. Install ventilation baffles into the space between the rafters before you install the insulation usually by stapling into place. Make sure it is flush against the wood as even a 1 inch gap can cause a 20 percent heating loss.

Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly. The ones i ve used are made of styrofoam and iirc they cost around 2. For rolled insulation place it between roof rafters. In finished attic rooms with or without dormer insulate 2a between the studs of knee walls 2b between the studs and rafters of exterior walls and roof 2c and ceilings with cold spaces above.

You can buy air ducts that staple to the inside of your roof above the eave vents and fit between the rafters. Time to get the insulation finished and get this place warm. Push the insulation in place between the rafters but be careful not to compress the material. You can use rigid foam panels or do as tom silva does with nearly all houses these days.

2d extend insulation into joist space to reduce air flows. For insulation to reach its full potential for preventing warm air migration it must maintain the. Then feed the rolled insulation under wires and pipe if either is present. Check out our how to video at the link below.