Reroofing Our House, March, 2020

Several months ago we decided to investigate having our twenty-year-old cedar shake roof replaced. This blog entry is a recollection of that process.

There are two kinds of roofing companies: those that do existing roof restoration and those that do roof removal and reroofing. They serve different markets and those companies that do roof removal and reroofing typically do not want to do roof restoration.

So our first step was to get bids from both kinds of companies. We quickly found out a roof restoration was going to be so expensive it made sense to focus on reroofing.

This led us to an investigation of shingle manufacturers and grades. We narrowed our search to CertainTeed and Owens-Corning and got bids from reroofers using several grades of products from both manufacturers.

What we discovered was that the material and labor warranties are completely separate, and the manufacturer warranties the material. The problem is if you as homeowner file a material warranty claim, the manufacturer will send an inspector. If the inspector discovers that the installation was done incorrectly they might deny the material claim and possibly void the manufacturer's warranty. CertainTeed will not do this, however some manufacturers will.

So, even more important than an extended manufacturer's warranty is the choice of an installer. Pick an installer that is highly-rated by the manufacturer. That way you can have confidence in the installation and the product. Also, every roofing manufacturer offers not only a variety of products, but a complete roofing system including underlayment. By using a single manufacturer's roofing system and an installer who is certified by the manufacturer to install it, you can be assured it will be done right and your new roof will be long-lasting.

After much deliberation we decided to go with CertainTeed, in part because we were impressed with the installer, and the references he had given us. He gave us a list of every installation he had done over the past twenty years - the address, manufacturer, roofing product and color. This made it easy to pick exactly what we wanted and we were even able to talk to thee homeowners who had had the roof installed.

CertainTeed has a very wide product line consisting of several grades: Landmark, Landmark Pro, Landmark Premium, NorthGate, Presidential and Presidential TL (triple layer) being some of the grades. While Presidential and Presidential TL are very popular (and expensive) we decided on a more standard shingle with a lower profile and a lower cost. We went with NorthGate because it is an asphalt shingle with a rubberized compound added which maintains flexibility and resists impact and cracking better than standard asphalt shingle. Each grade comes in a variety of colors and which one you choose is strictly personal preference. We chose Moire Black and are very happy with the result (pictures below). You can also select a premium grade ridge cap shingle which gives a slightly upgraded appearance at additional cost, but we decided against that.

Our installer gave us a bid of around $15,800 with the understanding that there could be additional hidden costs. Using Google Earth we estimated our roof to be around 2700 square feet in total size. In most new home installations, cedar shakes are installed over laths, so the shakes and the attic crawl space 'breathe'. In our case, however the shakes were installed over solid 1/2" plywood sheets. After twenty years there was rot and mold on the undersides of some of the plywood sheets and about 1/3 of the roof plywood had to be removed and replaced - 29 sheets of 1/2" CDX5 plywood, a total of 928 sq ft, at $75/sheet. In addition our roof had a very low pitch with vaulting in the rooms below. The space for insulation was not deep and worse, over the twenty years, the insulation had slid down and covered the soffit vents. So the installers used special pink plastic flexible corrugated batts, stapled to the soffit vents and folded down, to keep the insulation in place (pictures below). Finally, there were insufficient ridgeline exhaust vents, so more vents had to be added to bring the house up to code. In fact, over the garage there were NO ridgeline exhaust vents. Obviously the building code had improved over the past twenty years.

The installation took a total of five days - for removal of the old roof and installation of the new roof, and ended up costing around $18,300, which was what we expected.

When the installation was finished we asked the owner of the company to walk the roof and check the gutters. This is not something he normally did, but he did it at our request. He found a clogged gutter which he opened using our garden hose, and some left-over material which he collected. He also brought a rolling magnet, kind of like a hand lawnmower, which he ran over the yard, picking up old nails and staples that had come loose when the original roof had been removed. He also ran it over the driveway where the huge dumpster had been placed. 

In retrospect, my advice to pick a quality installer, rather than the least expensive one, was the best advice we could have received.

Here is a website I used to educate myself.

CertainTeed Shingles

CertainTeed.com

CertainTeed NorthGate Impact Resistant Shingles

CertainTeed Find A Pro