We always pay attention to the curb appeal and overall aesthetics of an Edmonton AB property’s residential roofing. However, we don’t too much in the structure that supports and maintains the entire roof itself. Roof decks are often secondary, and only professional Edmonton AB contractors with skill and experience discover rotted plywood under roof when homeowners decide to have a repair or replacement.

However, you won’t need to call a contractor all the time to discover if you have rotted roof decking. Often, rotted plywood under roof has indicators that signal when it’s time to replace them. Long Roofing has a good idea about this — check it out.

Clear Signs of Rotted Plywood Under Roof

One of the most common signs that a roof’s decking is damaged is a roof leak.

Water leakage can lead to ceiling spots or leaks, stains on interior walls, cracked paint, or peeling wallpaper. A quick inspection of the attic might uncover dark water stains on the rafters or in the insulation, or even light passing through holes in the roof. If left undetected, mold and mildew will develop in the walls, ceilings and insulation.

A sagging ceiling or roofline is another clue that there are major problems with a roof’s decking and the roofing structure. Soaked or waterlogged decking can warp, which can lead to a bowed or wavy roofline and ceiling.

Because your roof is so important and yet, so vulnerable to exposure and weather, the National Roofing Contractors Association recommends that you have your roof inspected twice a year—once in the fall, after hot weather has subsided, and once in the spring, after the danger of ice and snow is behind you. You should also have your roof inspected after a big storm, hurricane, or other potentially damaging weather event. (Continued)

If a roof deck section becomes rotten, does it mean you’ll need to replace all rotted plywood under roof? This is correct in the majority of cases. However, it doesn’t mean you’ll only order one form of roof deck plywood. Some roof slopes require thicker or thinner plywoods depending on roof slopes, rafters, and the general roof design.

SF Gate has a great enumeration of factors that determine the thicknesses needed to replace rotted plywood under roof and restore your roof’s durability and performance. Learn more about it below.

The Thicknesses of Plywood for Roof Deck Repairs

Plywood Is Layers of Wood

Plywood is made with three or more layers of thin wood glued together with the grain alternating. It is typically made in 4-by-8-foot sheets, although longer panels are available for special purposes. It is a flexible, durable, inexpensive covering for roofs because each panel will cover 32 square feet. It comes in multiple thicknesses from 1/4 inch to at least 1 inch; those above 1/4-inch typically have five layers of wood. The material cuts easily using a circular saw or handheld cutting tool equipped with a 3-inch multipurpose carbide wheel which lends to its popularity.

Many Factors Affect Thickness

The thickness of plywood used for roof decking depends on the roof slope, the spacing of rafters and the weight of other material to be put over the decking, as well as the design “load” — the amount of pressure exerted by various forces and the weather, especially weight of snow or ice accumulations. The wider the rafter spacing, the heavier the shingling, the lower the slope and the heavier the weather load, the thicker the plywood will have to be. (Continued)

Is it possible to DIY repair your rotted plywood under roof? It’s most definitely possible, but as responsible roofers who wish to help homeowners get the best results, we advise against it. There are many dangers and risks in DIY roofing that homeowners have to face and experienced roofers have already overcome.

However, as an educational reference, it’s great to read up on the process. In this way, if you hire a contractor, you’ll know the steps they’ll be taking, and you can contribute in post-repair evaluations too. Extreme How-To has an excellent guide that shows the process in its entirety.

Rotted Plywood Under Roof: The Easiest Steps

First Things First: Replace the Rot

First order of business was to remove the old deck and repair the rotted house wall and replace the window in the same process. The window was in a corner where two roofs met and formed a valley. Water runoff from the roof valley was overshooting a damaged gutter and soaking the window. Water eventually entered the window sill area and rotted the 2×4 sill-framing and plywood sheathing behind the cedar clapboards.

Luckily we only had to replace a few 2×4 studs and window framing since the water damage stopped at the house rim joist. Once the framing and 1/2-in.

The plywood sheathing was replaced, we installed a new maintenance-free window and covered the entire house corner with Grace Ice and Water Shield.

Note: Ice and Water Shield is a self-adhering membrane that is mostly used as roofing underlayment because of its ability to provide leak protection for sloped roofs and to resist water penetration due to water back-up (ice dams).

We trimmed the window with PVC trim and sided the wall with pre-primed cedar clapboards. Care was taken to prime the end grain of the clapboards; to install rubber flashing at all vertical seams; and to use only stainless steel fasteners. We were looking for a long-term fix.

Repairing the Water-damaged Roof Framing (Continued)

Remember, it can save you more time and money working with professional Edmonton AB roofing contractors than attempting rotted plywood under roof repairs on your own. If you have yet to find a reliable roofer, you can count on DDCL to help you. We have decades of experience handling roof repairs. Allow us to help you today — call now!