How To Tell If Plywood Roof Deck Needs Replacing

If you can see original wood shingles on the underside of your roof when you re up in the attic you ll need not only to tear everything off but also to install new plywood decking all of which likely adds 5 000 or more to your costs.

How to tell if plywood roof deck needs replacing.

So arm yourself with a flashlight and climb up under the eaves. A failing roof deck will impact the integrity of a roof. Since the boards used for shiplap were manufactured here in the pacific northwest it was still cheaper than plywood up through the 1960s. Splits can form in the planks and they will get longer from the heat in the attic.

Sometimes it is just best to resheet it to give you the best deck for your new roof. If you think you might need a new roof the first place to check isn t your home exterior it s your attic. Other s ymptoms of a failing roof include high energy bills and ceiling stains. Roof decks on homes built before 1970 are often 1 8 fir pre plywood shiplap.

Missing shingles are caused by natural weathering high winds age and possible improper fastening. The inspection should take place when the old shingles have been removed. Lack of ventilation in the home can lead to mold and mildew which can grow on roof decking if moisture is in the attic and cannot escape properly. Until the 1940s exterior grade plywood was not available.

These are the things an experienced roofer can tell you after the deck is cleared of all shingles. You walk on it you check the spacing between rafters you determine the thickness and if is it plywood or osb. That moisture can lead to rot and damage in the roof deck. I replaced a roof last summer which had a deck made of 1x6 planks so you see there are various types of decks.

A sagging ceiling or roofline is another clue that there are major problems with a roof s decking and the roofing structure. Knots in the planks can cause it to break after the roof is done so if it looks iffy it is best to replace it. The tear off gets a lot more complicated if you have something other than asphalt up there.