9 Residential Roofing Layers You Need To Understand

Your Missouri home is a complicated collection of separate systems. You’ve got your electrical system, plumbing, and then you’ve got your roofing system. Let’s take a deeper dive into the nine layers of your residential roof

1. Framing

Your interior ceilings have joists over them. These attach to your home’s exterior walls. Roof rafters connect walls and joists, providing the slope (pitch) of your home’s roof.

Most residential roofs are “steep slope” roofs, with rafters raising several inches for every foot of horizontal run. The rafters must be structurally sound, free of insect damage and rot, and spaced correctly to support your roof’s weight. 

2. Insulation

The floor of your Missouri home’s attic must be well insulated so outside, untreated air (attic air) never mingles with interior, treated air. Proper insulation keeps out humidity, provides for a comfortable home all year round, and helps dampen sound. 

Blown-in insulation installed by professionals generally does a better job than rolled batt insulation. Your home benefits from having at least R48 attic insulation, though R60 is better. 

3. Ventilation

The air inside your attic should match the air outside in both temperature and humidity. This is key to preserving your home and roof. Proper ventilation achieves this. 

Ventilation comes from several sources, including gable vents, soffit vents, and ridge vents. Your roofer may also suggest artificial ventilation with fans to move air through the attic space. 

Worried about energy savings? The insulation in your attic is the important factor in separating outside air from your treated indoor air. The attic air is kept apart from your home air by the insulation. 

4. Roof Deck

What is roof deck sheathing? Sheathing is the wide board material which provides a firm foundation for your surface roof material. These sheets may be plywood or Oriented Strand Board (OSB). They are always nailed down onto rafters, staggered, with small gaps between boards to allow for thermal expansion. 

Why stagger roof sheathing? The staggered pieces form a stronger roof. Most building codes call for staggered sheathing to increase shear strength. 

If you see small gaps between sheathing pieces, don’t worry. If, though, you can see light from outside when you are in your attic, something is amiss. Contact your local residential roofer immediately.  

5. Water and Ice Shield

The lower three to six feet of your roof edge is usually covered in water and ice shield. This material can also be used in valleys and along roof hips as additional protection. 

In very cold temperatures, ice dams can form along the edge of the roof. This can lead to water infiltration from freeze-and-thaw cycles. Water and ice shield is a thick synthetic or natural rubber membrane which prevents water from seeping into the sheathing.

6. Underlayment

The thin, often self-adhesive material which rolls out to form an additional waterproof barrier across all of your roof’s sheathing is underlayment. It seals around nail and staple holes, keeping water off the sheathing and out of your home. 

When dealing with minor roof repairs, underlayment must be replaced to prevent water damage to sheathing, rafters, and insulation. 

7. Ridge Vents

Soffit vents under the eaves allow outside air into your attic. Natural convection currents move this air up along the underside of sheathing, but without ridge vents, the air has nowhere to go. 

Ridge vents today match the field material covering the rest of your home’s roof. They provide ample space for air to exit your roof while also preventing insects or rodents from entering your attic. 

8. Field Material

Your home’s roof field is the broad expanse of most of the roof surface. Covering it is a material you and your roofer, or the previous owner, selected. This could be metal, tiles, slate, cedar shakes, or shingles. 

Repairs and replacement of the field material cannot be left to any old roofer. You need a reliable, trusted, and local roofer for this work. Look for a roofer experienced in working with the same material as your home’s roof:

9. Flashing

The thin metal which covers over areas from one material to another, such as around chimneys and in roof valleys, is flashing. The material you find in do-it-yourself (DIY) home improvement stores is thinner than what professional roofers use. 

When facing repairs or replacement of flashing, invest in professional work. The thicker material will outlast DIY products, and experienced roofers can install it correctly the first time, helping to avoid water leaks or more damage to your roof. Midwest Roofing is your preferred residential roofer from Columbia to Springfield. Contact us today to learn more about our many services, from minor roofing repair to annual inspections to complete roof replacement.