Roof Decking & How to Care For It

Roof decking – also known as roof sheathing – distributes the weight of shingles and tiles on the timber rafters. It is also the home owner’s primary defense against roof leaks and moisture damage.

So far so good but there’s only one catch. Roof decks are made from trees. And the DNA of trees dictates that wood will eventually rot, no matter how hard humans try to defer the moment.

Fortunately there are ways we can delay the day of reckoning, when a roofer shakes their head and thoughtfully says ‘Your roof decking has had its day. The shingles must come off first, and I’m afraid it’s not a cheap job.’

How to Extend the Life of Your Roof Sheathing

Most roof decking is either plywood, or a composite known as oriented strand board bonded by waterproof resin. It’s not ideal but it provides the best cost-benefit solution, and our industry will keep using it until something better arrives to replace it.

Moisture is wood’s worst enemy. It does more than soften the material. It also creates an environment where fungi can flourish, and break the material down. Wood treatments can delay the onset. However, once the fungus penetrates deep, it’s just a matter of time.

Roof decking life-extension is therefore a theoretically simple matter of keeping it dry. This means taking proactive steps to avoid the following:

1… Aging, curled shingles admitting driving rain, and progressive snow melt

2… Blocked, overflowing and leaking eavestroughs and down spouts

3… Ice dam buildup that can force moisture in, thanks to its sheer weight

3… Torn flashing and deteriorating sealing at parapets, gullies, and chimneys

4… Warm, damp humidity rising in the attic from the living space below

5… Insufficient, or blocked roof ventilation that allows moisture to collect

Best Repair This Damage As Soon As It Starts

Rotten wood has had its day, and we can’t repair it. However, skilled hands can cure the damp, cut out the damaged sections, and replace them with new plywood or orientated strand board.

Once rot is in your roof sheathing, it can spread surprisingly fast. But if you move quickly, you may be able to extend its life for more than a few years.

Speak to Valiant Exteriors for more information. We are one of Calgary’s leading roof specialists. Call our offices on Country Hills Boulevard, NW Calgary telephone (403)829-1661, or email us a message if you suspect you have a rotting roof deck. Let’s start the conversation soon while time is on our side!

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Roof Sheathing on a Home (Image Billbee BY CC 2.5)