Installing roof material over wet or wrinkled barrier (decking) is against roofing code in most areas. Shingles will not adhere properly to wet roof decking like OSB. Keeping water trapped in roof decking can cause the roof to eventually swell or buckle. Trapped moisture can cause mold and mildew growth.
A: It is never a good idea to install a roof over wet plywood or any type of roof sheathing. Trapped water will boil when the sun heats the roof and the shingles will then have small pits where the steam finally escapes.
Plywood can typically withstand rain exposure for a day or two without significant damage, depending on the type of plywood and the severity of the rain.
Solutions For Wet Plywood
One effective method is to expose the plywood to air and sunlight. This natural combination works wonders in drying out moisture. Just lay out the plywood in a well-ventilated area where it can absorb heat and dry air.
Can roofers install a roof when it's raining? No, a roofer cannot (correctly) and should not install a roof when it's raining. Whether there's rain in the forecast or a pop-up shower, no roofing work should be done when the roof is wet.
That's why most licensed practitioners recommend 40℉ as the cutoff to install asphalt shingles. Experts consider dry, warm weather the most opportune time to install a new roof. The best time to install a roof occurs when the temperatures average between 70℉ and 80℉.
Rain can also make it harder to sealants and other materials to dry or be secured in place properly. Aside from the damage it could do to your home or unfinished roof, rain is harder to work in. It might even be unsafe for roofers to work on your roof during rain, so these aren't risks you should take.
This includes oxygen, temperature (between 65 and 95 degrees), moisture (20% for dry rot and 50% for wet rot), and food (wood). In general, dry rot can appear between 7 and 10 days after the wooden element has received enough dampness. If the spores are older, they may take longer to germinate.
It's critically important to make sure the underlayment is completely dry prior to shingle installation.
If a light rain with just a few drops and low wind won't generally cause enough issue to have to halt the process. But if a heavy downpour occurs, contractors must quickly tarp the roof and all materials as soon as possible.
The effects of rain on firewood
A short, light shower is unlikely to do much harm, but a prolonged downpour can indeed cause problems. When firewood gets wet, it becomes more difficult to light and it burns less efficiently, producing more smoke and less heat.
Signs Your Roof Deck is Ready to Be Replaced
Cracked or deteriorating plywood and OSB boards are present. Noticeably sagging or soft spots are visible on the roof deck. Obvious watermarks can be seen on the roof's support structure. Mold or mildew is visible on the roof decking.
Quality materials provide better durability and weather resistance, ensuring long-lasting protection for your shed. Work in dry conditions – it is essential to install shed roof felt in dry weather conditions. Wet or damp surfaces can compromise the adhesive and affect the felting's effectiveness.
A roof typically dries within 24 to 48 hours after rainfall, subject to weather conditions, the roofing material, and the roof's architectural design.
You need to put down a synthetic felt (which is like tar paper; they come in 4-foot rolls and are made out of paper, tar, oil, and other things) or underlayment, and you want to put that down before you put the tiles down.
Installing roof material over wet or wrinkled barrier (decking) is against roofing code in most areas. Shingles will not adhere properly to wet roof decking like OSB. Keeping water trapped in roof decking can cause the roof to eventually swell or buckle. Trapped moisture can cause mold and mildew growth.
Generally, if common plywood gets wet for an extended period of time, it can swell and lose shape which eventually leads to the layers of wood splitting apart. This often occurs when plywood is stored outside for even a short timeframe before a project begins.
Allow the roof to dry completely before shingle installation to ensure proper adhesion and prevent moisture-related issues. Waiting at least 24 hours for any moisture to evaporate is recommended.
Moisture is the primary factor that promotes mold growth on plywood. This moisture can come from various sources, such as leaks, condensation, or high humidity levels.
The simple and short answer to this is no, wet rot will not dry out on its own. A wet rot issue will continue to exist and progressively get worse until the source of the moisture is completely removed. Basically, your wet rot isn't going to be eradicated without treatment following a proper survey.
Plywood is made of layers of wood veneer glued together. The wood fibres will expand, warp and rot when subjected to prolonged wetting from rain, ground moisture or plumbing leaks. Waterproofing creates a protective barrier.
Conclusion. While it's technically possible to shingle over a wet synthetic underlayment, it's best to avoid doing so. The potential issues, such as trapped moisture, safety risks, and shingle adhesion problems, can lead to significant damage and expensive repairs down the line.
Generally speaking, you shouldn't install a new roof in the rain. Never, ever climb on your roof during lightning storms. After rain, let the roof dry for a day before continuing work.
If properly applied that underlayment will keep water out for months and withstand significant prolonged rain. It might leak if they attached it with staples but if the used cap nails/staples it will be fine. Don't worry too much even if it does leak it won't be too bad.