Insulate Roof Rafters Properly

Airspace from the soffit to the ridge by installing a continuous air chute in each rafter bay.

Insulate roof rafters properly. With a warm roof the usual process is to split the insulation into two layers. Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly. Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away. 2d extend insulation into joist space to reduce air flows.

Stacking insulation between rafters warming of a flat roof. Interior closed cell foam and blown in fiberglass or cellulose. The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow. To install the air chutes staple them directly to the roof decking.

If the plastic sheeting is in pieces overlap the pieces by 8 inches and staple it in place directly to the roof rafters and the wall. Attic moisture problems are often the result of heated air from the living space rising up into the attic which is not heated. If there is a floor you will need to remove it to properly insulate the roof rafters. Do not use plastic sheeting in this case.

Place the plastic sheeting on top of the rolled insulation. In order to avoid damage to the roof deck you should insulate ceilings to create an air barrier between the living space and an unfinished attic or airspace underneath the roof deck. For the same reason insulation shouldn t touch the roof s underside. If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running across the 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. Staple them directly to the roof decking for better insulating roof rafters. To effectively ventilate your roof create a 1 in. Spray a more moderate thickness of closed cell polyurethane foam on the underside of the roof sheathing supplemented by a layer of air permeable insulation below and in direct contact with the underside of the cured spray foam.

When it is necessary to insulate the roof the better to insulate the roof materials how to properly insulate the roof. If your attic is going to be converted into livable space then you will need to insulate the roof rafters.