Roof Replacement Case Studies: All New Roofing Plywood over Furring Strips in Willimantic, CT

Thursday, March 2nd, 2017 by Kevin Marr

Challenge

This 2-Family home in Willimantic had an old 30-year roof that needed to be replaced. However, there was no plywood underneath the old shingles. This is a common dilemma with homes that at one time had Cedar shingles on the roof. Instead of Plywood, the roof had thin strips of wood called furring strips. Furring strips are important for Cedar roofs because it allows the wood to breathe and stays dry. However, furring strips are not strong enough to hold asphalt shingles. Furring strips also are spaced apart by 4"-5" which means if an asphalt roof is installed many of the nails will no be secured to the furring strips. Many times, a second layer will be installed on top of the cedar shakes without dealing the underlying issue; the decking.

Solution

So instead of re-shingling over the roof, we tore off the old roof and installed 1/2" CDX plywood over the furring strips to reinforce the roof deck so the new Desert Tan shingles could go on. The plywood does not add a lot of weight to the roof. Stripping the shingles down to the decking also allows us to install Ice & Water shield and Synthetic underlayment. Not only does replacing your roof stop the leaks coming into your home but it deals with any underlying issues that need to be fixed as well. If your home has thin furring strips or Tounge and Groove boards, make sure your roofing contractor installs a fresh plywood deck over the existing decking to ensure all gaps are covered and the roof has the strength to hold the shingles on your roof.