Attic Insulation Rafters Or Joists

If you want to install standard r 38 insulation.

Attic insulation rafters or joists.

The batting material must be faced and. Joists are the parallel horizontal beams that run across an open space joining opposite walls in a building to support both the ceiling below and the floor above. Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly. 2d extend insulation into joist space to reduce air flows.

The ceiling load may include items like drywall ducts recessed lights bathroom fans and attic insulation. You can use rigid foam panels or do as tom silva does with nearly all houses these days. Polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials. Unless expressly built so an attic s joists are meant for carrying the load of the ceiling below and related elements collectively known as the dead load.

In practical terms you can choose between mineral wool or insulation boards. The ceiling joist system is typically constructed from substantial two by tens or larger dimension boards but some older homes have smaller joists. If you decide on mineral wool such as glass wool or rock wool you will need to put down a damp proof membrane. Hire a pro to install spray foam insulation.

Even rafter insulation can encourage damp as it stops draughts and reduces natural ventilation. Install batting between the attic s floor joists. Joists are traditionally made from timber. Insulation between the joists will make your attic much colder so this could worsen your damp problem.

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. So insulating the floor of the attic is not only the best solution but it is also the simplest and cheapest. 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.