At some point in the lifetime of your roof, your roofing contractor may inform you that your roof needs to be replaced. In discussing the options and other considerations, you roofer may include resheeting your roof. Most homeowners would probably ask “Is that important?” If your home was built before 1970, that answer is likely “yes”.
Homes built before 1970 were likely built using a type of substrate called shiplap. Shiplap is 1 x 8 inch fir wood planks used to create a solid surface to attach the shingles to your roof. Before the 1940’s, exterior grade plywood wasn’t an option. After the 1940’s, it was still cheaper to use the shiplap boards, since they were manufactured in the Pacific Northwest. It wasn’t until the 1970’s that exterior grade CDX ½ inch plywood became the common type of substrate for roofs.
There are several problems with shiplap style substrates that occur over time. Roofs that still have shiplap are at least 50 years old. Wood that old has almost always dried out, meaning the resin has dissipated shrinking the wood and making it brittle. These dry wood planks will likely have gaps between the boards allowing for leaks. Wood planks also have cracks and knot holes, which are also likely to leak.
Another common practice is applying an underlayer over the shiplap, which is also likely to be damage due to age. This is almost certain if subsequent shingle layers were applied over the original roof. It’s not uncommon for roofs of this age to have multiple layers of shingles. Each layer creates nail holes in the layers below. Each new hole, crack and void creates an opportunity for the roof to leak.
Another issue when installing a new roof over shiplap is that the spaces in the old ship lap means that the nails securing the new roof aren’t actually sunk into the shiplap, leaving the new shingle unsecured to the roof. This provides the opportunity for wind and rain to damage the new shingle and leak.
Your New Roof
One way to solve all these problems is to remove the entire roof, and start with a new substrate, vapor barrier, and shingles. Removing ship lap is time consuming and expensive. The most efficient and cost effective option is to resheet directly over the shiplap with exterior grade plywood. This is acceptable by code, as well as the roofing manufacturers. Your new composite shingle will be installed securely to the new solid surface and last for years leak free. Your biggest investment is your home. And when you need a new roof, you need it to be installed correctly.
When your home is ready for a new roof, repairs, or maintenance, you need a reliable, dependable roof repair company. You count on you roofing contractor to keep your home safe and dry. Guardian Roofing is committed to providing top-quality service, professionalism and workmanship. If you are looking for a roof repair contractor please call us today at 844-499-7822 or complete our online service request form.
