What Is Soffit and Why Is It Important to a House?

There’s a good chance your building has soffit installed. Just walk outside your door and look up at the roof. The material connecting the roof overhang and the side of your building? That’s soffit.

The word “soffit” is derived from the French language, and literally means “something fixed underneath.”  It’s most commonly used around a building’s main roof, but soffit can also be used under porches, under arches or columns, under a flight of stairs… pretty much anything that has a visible ceiling. It is commonly made in aluminum and vinyl, as well as fiber cement, wood, and steel.

For this article, we’ll focus on soffit for its primary use — the roof overhang.

soffit diagram

Soffit serves both an aesthetic and functional purpose for a building’s roofing system.  It’s the skin that covers your eaves — without it, you would see your rafter beams fully exposed. Cover it up with soffit, in the style and color that you like, and you add some instant and easy character to your building.

Functionally speaking, soffit protects your rafters from the weather elements. If your rafters are exposed in any areas, you’ll likely have mold buildup and rotting beams to replace — which definitely won’t make for a fun (or cheap) Spring. Plus, mold in a home is never healthy.

Also, soffit helps your building breathe.  With vented soffit, air can flow through the vents to provide regular air circulation to your attic. Air flow is tremendously important for your entire home.  If you have lanced style vents (like the vented soffit we offer our customers) you can achieve proper air flow while limiting the moisture that can enter through the vents.

If solid soffit is more of your style, no problem — just make sure you have vents installed to enable proper air circulation through the attic. Or, for every few soffits you install, you could install a vented panel to assure air flow.Soffit-solid-diagram

Imagine if your eaves were sealed tight instead. In the hot summer months, your attic would draw in (and hold) heat. That sweat running off your head? It would definitely be from your attic overheating, but also likely from looking at your high utility bill as well.

In the winter months, snow and rain would ultimately lead to moisture buildup, and you would eventually have rotting and/or mold in your rafters and sheathing.

Bottom line  — you need to let your attic cycle the heat and moisture away from your house. Soffit is the most common and easy way to protect your roof frame and achieve air circulation to keep your building healthy.

If you’re not a candidate for soffit for a given reason — say your building does not have eaves — I suggest you ask a builder to look at your attic and offer custom suggestions to improve your air circulation.

Which Type of Soffit Should I Buy?

Based on sales volume of homes and buildings across the US, aluminum and vinyl soffit are the runaway winners. They are the most cost effective to manufacture, the easiest to install, and they weigh less than the alternatives. Let’s run through the pros and cons for aluminum and vinyl:

Pros of Aluminum Soffit

  • A malleable material, good for fitting into varied spaces.
  • Highly durable. Will not rot, chip or crack.
  • Non-combustible, in case of fire.
  • Easy to keep clean, does not attract dirt.
  • Water-resistant. Ideal for wet regions.

Cons of Aluminum

  • Tends to be more expensive than vinyl. If you’re covering a large area, the aluminum cost will add up.
  • Can dent if enough force is applied.
  • Does not insulate as well as vinyl.

So, how about vinyl?

Pros of Vinyl Soffit

solid soffit for a porch

Solid soffit for a porch ceiling. Photo credit – Siding World

  • Tends to be the most affordable option.
  • Best material for insulating your home.
  • Often available in different textures and grains. More customization over the look you want.
  • Will not rot. Pretty resilient against cracking and chipping.
  • Water resistant. Excellent for high moisture areas.
  • Easy to clean.

Cons of Vinyl

  • More easily affected by heat. Can discolor more quickly over time.
  • Can become brittle if exposed to regular sunlight.
  • Can develop mold in damp climates.
  • Not as malleable as aluminum; more difficult to cut, bend and install into varied spaces.
  • Some feel vinyl is a cheaper looking product.

And what about the other materials?

People who opt for soffit in materials other than aluminum or vinyl typically make their decision based on aesthetics. Why?

Wood is more expensive and will ultimately rot over time. However, I am personally a fan of wood — it looks natural and timeless. It adds tremendous warmth. If you choose to install wood soffit, just be prepared for the time and money to replace the panels over time. Plus, don’t forget to install vents for air circulation!

Steel will be much more durable than any of the alternatives, including aluminum. Some suppliers also carry steel soffit in a variety of colors. Steel will just run about 25-40% higher in cost than aluminum – but overall, steel could be a great option for your soffit.

Fiber cement is less common and among the pricier options in soffit, but there are suppliers that carry panels in varied wood grain textures, vents and colors.

Still have questions? We’re here to help.

We actually manufacture soffit and help hundreds of end customers a year walk through building products related questions. If you have more questions for us, just give a call and we’d be happy to help. Our phone number is 1-610-779-1357. Also you can shoot us a quick message if that is easier. We’ll get back to you within 24 hours to offer all the personalized, no-salesey help we can.

Best of luck with your soffit installation. Either way you go, we’re sure you’ll make the best choice for YOU.

About Justin Knabb

Justin Knabb is VP of Operations at Specialty Design and Manufacturing, a family-run, US manufacturer of custom home building products as well as custom industrial machinery. Justin is a fan of microbreweries, traveling, Apple products, and Philly cheesesteaks. He can be reached at 1-610-779-1357 or here.


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