Attic

Connecticut Home Inspections

SITE NAVIGATION

Resources

Site Search

There are three major items to inspect in attic areas, the framing, insulation and ventilation. The attic is also a place that provides additional perspective to how well the roofing and flashing components are functioning. Water stains found in attic areas can be evidence of a failure of these components; however, it is not necessarily evidence of a current problem. It has been our experience that many homes, which are only a few years old can have stains. However, the cause has been repaired so there is no current leak. Sometimes the home inspector can make known these stains but only ongoing observation during rain can determine if there is a current problem.

FRAMING
Attic framing varies depending on the type of house, its age and the type of building material the builder chooses to use. Age plays the same factor in attic framing as it does in basement framing. Unless some type of renovations have been performed, the attic framing method will be the same as the method found in the basement or throughout the rest of the house. Older houses typically have longer spanning rafters separated farther apart then modern homes (see right). Roofs may appear wavy with bumps and sags from settlement. Very often this is typical and only ongoing monitoring is recommended. Sometimes these deflections are more serious and your home inspector is there to make these determinations.

More modern homes have larger rafters installed closer together. Many homes are built with trusses, which are pre-fabricated framing structures that have the rafter boards and ceiling joist tied together by a variety of cross braces. The framing components for trusses are much smaller and lighter due the cross bracing. The light weight and pre-fab characteristics can cut down significantly on labor time during construction. In addition to the rafters or trusses used, the sheathing installed over these to support the roof shingles vary also. Some homes have plywood, others have horizontally installed 3/4 inch boards, some use what is called OSB (Oriented Strand Board). Some houses do not have formal sheathing at all. Houses with wood shingles only have small 4 to 6 inch boards spanning the rafters, separated from each other by about 4 inches. The photos below and to the right show a house with wood shingles from the attic view.

The photo above on the left show 2 X 6 wood rafters with horizontal board sheathing very stained from water seepage. In spite of the significant staining, the framing structure is still very much in tact. This particular water leak had been repaired many years earlier and no longer leaks. An inspector visiting this house (and not knowing it's history) during a period of warm sunny days would have no way to be conclusive as to whether the cause of these stains were current or something of the past. A moisture meter would indicate that the wood was dry but may only mean that the wood has had enough warm weather to dry it out. Questions must be asked of the seller regarding the history of stains like this. If no concrete evidence can be obtained, further evaluation by a roofer may be needed. At the very least, this area will need ongoing monitoring.

The photo to the left has OSB sheathing. Collar ties are installed horizontally between rafters for additional support. Collar ties are not always found and may not be necessary if there are no deflections in the roof.

Newer homes typically use plywood or OSB sheathing. These types of materials provide adequate strength if proper rafter spacing is present. Attic ventilation is very important when plywood and OSB is in use. Trapped moisture in attic spaces will soften and cause delamination to

INSULATION
Insulation also comes in a variety of forms. Fiberglass, Cellulous, vermiculite and others are found in attics. Insulation is rated by "R-Factor." The Department of Energy recommends R-49 for attics. This does not mean much to anyone unless you put it in simpler terms. Blown in fiberglass insulation will need about 18 to 20 inches to reach R-49, blanket or bat insulation needs over 12 inches. Very few homes have this much insulation.

Blown in, loose fiberglass insulation.

Blanket or bat insulation.

VENTILATION
Proper ventilation in your attic is needed to reduce the effects of heat and humidity. These two elements can be costly to the structure and energy efficiency of your home.

Heat: In the summer, an improperly vented attic can reach temperatures of up to 150 F. These kinds of temperatures can reduce the life expectancy of your roofing materials. It will also make the interior temperatures of the home less comfortable and increase the cost of home cooling.

Humidity: Most of the humidity comes from within the home. Every time you shower, dry clothes, cook, run water or even breath you are releasing moisture into the air that can find its way up into your attic. During the colder months this moisture will condensate and seep into the rafters and roof sheathing. Once in the wood it can create mold and decay in the wood. Delamination can occur in plywood sheathing. Roof shingles are affected as well.

With the proper amount of attic ventilation you will prevent damage to your home, allow your roofing materials to last to their design life, reduce energy use and make your home a more comfortable place to live.


Attic fans that function with thermostats and humidistates are an excellent method of venting the attic.	Louvered gable vents are very common but often too small on older homes.

In the three photos above you see an entire ventilation system for the attic of a newer home. On the ridges of the roof there are ridge vents as seen in the photo to the left. These allow heat and moisture to escape from the attic. In order for this heat and moisture to escape properly, inlet vents for fresh air are needed such as soffit vents as seen in the photo in the center. In the attic, baffles are placed between the rafters near the eaves so insulation does not block the soffit vents. These baffles are also used in homes with vaulted ceilings to provide air flow from the soffit vents to the ridge vents.

This Cross section of a cape shows how modern capes would be ventilated. Older capes usually insulate between the rafters all the way down to the eave. This provides poor ventilation and causes heat loss into unused attic space. Removing the insulation from the rafters in the lower crawls space and insulating the floor and wall in this area is more energy efficient and makes venting easier. Older capes often do not have a soffit area for inlet vents. In these cases, small louvered vents can be installed in the end walls of the crawl space after the insulation has been relocated to the floor and wall.