I took a call from a Senior level claims adjuster for one of the big three insurance companies this week about decking on a Hardishake roof?
So, here's the scoop on Hardishake Decking:
Back in the early '90's, Hardishake had two different levels of installation and they both related to the Fire Rating. You could get a "Class A" Fire Rating by using solid decking or a "Class C" Fire Rating from installing the product over an open lathe deck.
Why would anyone want to install Hardishake over the open lathe?
Great question... Hardishake first came to prominence in the Southwest as a high-end replacement product for wood roofs. The Hardishake shingles were more expensive than even the highest quality fire-treated wood shingles, but were within reach if the homeowner was willing to pay a little more or the roofing contractor may have be willing to discount their normal rate to get the job.
The problem was that wood roofs were built on the open lathe decking system (great for ventilation when using wood shingles). So, almost by default, most of the Hardishakes that were originally installed were the "Class C" variation. The old wood shingles were torn off and the new Hardishake shingles were installed without putting down a solid dock. Primarily because adding the solid decking would be a major financial investment.
Fast forward to the mid-late 90's and we find several new home builder specs using Hardishake as the roofing product. With these types of installation, it was almost as cheap to build the roof system using solid plywood or a full sheet of particle board. Depending on the price of lumber, it may have been cheaper than using the open lathe system... and was certainly easier for the construction crews to build. Open lathe is an art form taking more disciplined measurement and oversight. So, with it being cheaper and easier to use full sheets of decking, these later new-home installations were almost always "Class A" versions.
If you're trying to get your old Hardishake roof replaced, you'll most likely be wondering what type of high-end roofing products you have to choose from - a lot of your choices will come down to what type of decking system you have installed already.
Open up your attic and look at the bottom of your roof. If you see solid plywood or decking, you'll have many more choices. If you see slats of plywood (open lathe), your choices will be more limited unless it is the practice of your insurance company to pay for new decking.
If you need help getting your Hardishake roof replaced, contact the Hardishake Specialist today.