ROOF AND CEILING INSULATION

Ceiling (and roof) insulation is usually associated with attic insulation. Even if that insulation demands lifting the roof, it may be a deserving task and investment. The benefits can be huge.

Insulation roof-ceiling Types

In cold climates, the insulation is usually restricted to the ceiling (or attic). In hot and warm climates insulation may also reflective insulation for the roof (besides ceiling-attic insulation).

See on this issue:

Attic Insulation
Reflective Insulation.

Types of roofs & Insulation

If your home has a pitched roof and an open attic, the insulation should be applied in that attic. Just inspect the existing insulation and determine your insulation needs. Your roof or ceiling needs at least a R-45 insulation (though a R-60 isn't to much). If it has less, then add enough insulation to perform the recommended amounts. Your payback will be short.

If your roof is tall enough, installing extra insulation isn't usually a big problem. The most common solution is to to blow enough loose-fill insulation (e.g. fiberglass) into attics and roof cavities. But if you have a flat roof or if your home has a vaulted or cathedral ceiling, than the issue isn't so simple.

Flat roofs and cathedral and vaulted ceilings

Flat roofs and cathedral and vaulted ceilings have often a small attic cavity. The new insulation should fill some or all of that cavity, even if it is only one feet deep or so.

This is not an easy task, and it is better done by professionals. The small attic cavity limits the amount of insulation you can install (wich may demand a high-density insulation material) and put problems of ventilation, hard to solve and usually controversial.

Structural approaches in bad designed ceilings and roofs

In many cases - since flat and vaulted cathedral ceilings represent poor designs - it may be necessary more structural approaches:

1) building a pitched roof over the top of the flat or nearly flat roof, creating a new attic and installing the insulation in it;

2) adding high density foam insulaton on the top surface and above the roofing of the vaulting ceiling.

Both of these solutions demand outdoor works, which is often desirable, though it may be considered an interior solution (similar to the exterior one) to the second approach.

Insulation Materials and R-values

Ceiling insulation materials and their R-values are those indicated to Attic Insulation.

The reflective materials used under the roofs (in hot climates) are usually a layer of RFL sarking or foil batts. When installing a reflective material, make sure that there is a minimum gap (of 1 inch / 2,5cm) between the roof and the RFL. In the case of sarking, just install it between the battens and the rafters, with its shiny side facing down.

See:

Reflective roofs
Reflective roof materials