Roof Vs Ceiling Insulation

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Roof vs ceiling insulation.

While ceiling insulation is a simple job for a diy er s new or existing build roof insulation can only be installed during the construction of a new roof. Unvented hot roof design cathedral ceilings are also an option. Wall insulation is not suited for use in a ceiling cavity space and wall insulation r values would not be adequate for your ceiling area. Additionally insulation serves as a way to enhance sound proofing on the uppermost envelop of your house.

Check garage walls and ceilings that are adjacent to conditioned spaces. Water is insulation s enemy. It s more effective and easier to install insulation on the attic floor than in the roof assembly. Looking upward through the open ceiling if the exterior wall and roof deck assemblies both contain spray foam then a continuous insulation and airtight layer is established from the base of the walls to the peak of the roof.

A very energy efficient enclosure results. See the department of energy s doe ranges for recommended levels of insulation below. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. The highest r value that wall insulation reaches is an r2 7hd however we recommend a minimum of r4 0 for ceiling insulation.

If you do need to install insulation in the roof assembly take into account some rules. Insulating in and around your roof attic space also prevents long term damage from moisture build up or ice damming which results from the warm air trying to escape through the apex of the roof but instead heating up the snow. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. For example cathedral ceilings built with 2x12 rafters have space for standard 10 inch batts r 30 and ventilation.

Box out light fixtures. Ceiling insulation sits on top of your ceiling plasterboard whereas roof insulation also known as roofing blanket sits directly against the underside of your metal roof. Unless in air conditioned attics insulation is typically installed on the ceiling plane not on the sloped roof assembly. Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be.

Turn off the electricity then remove an electrical outlet cover for a view of exterior insulation. Check behind knee walls which are walls between living spaces and the garage or attic.