6 Comments

1. GBA Editor
   MIKE GUERTIN | Oct 27, 2023 07:33am | #1

   Great profile of the Fortified program Randy. The simple upgrades and small changes to standard installation practice can make a big difference. There are two related resources on the Fine Homebuilding website. One is a webinar on roofing in high wind zones focusing primarilly on asphalt shingle installation ( https://www.finehomebuilding.com/project-guides/roofing/expert-session-windproof-a-roof ) and the other an article https://www.finehomebuilding.com/project-guides/roofing/9-upgrades-to-windproof-your-roof

1. 
   Randy_Williams | Oct 28, 2023 05:34am | #2

   Thanks for the additional information Mike!

2. 
   owen_p | Nov 03, 2023 06:59am | #3

   Hi Randy,

   Thank you for the article.

   Could you expand on this statement:
   "The first is to use a self-adhering membrane over the entire roof. Depending on your climate, type of self-adhered membrane, and choice of finished roofing material, this may or may not be a good idea. "

   Specifically in my case, Ottawa, Ontario, a solar contractor who started in roofing but now does less of that than solar PV is proposing 100% roof coverage with ice and water shield (vented 4/12 pitch roof, well air sealed and insulated attic) - before installing new higher end shingles. The thinking is that this approach minimises the risk of leaks from solar PV racking mounts.

   During the roof install we will be removing the first row of roof sheathing to allow the proper installation of SmartBaffles from above (followed by cellulose top-up to R-60).

   The current decking is 3/8ths and soft in spots so we plan to add a second layer of 1/2" on top and this is what the ice & water shield would be applied to. Assuming that there is already 3' of ice and water shield on the perimeter we may end up with a sandwich assembly here...

   Does this sound like a dumb idea to make the roof "fully impervious" from the top side? The soffits are continuously vented and we are putting a 2" airspace in to 4" vertically above the cellulose with good ridge vents that stand above the snow.

   I am also implementing aspects of the Fortified system and in fact had their high wind checklist out when I met with the roofer. I've reinforced our single gable end-wall and plan to add Simpson Strong-tie screws to secure the trusses to the double top plate from the exterior during a future exterior continuous insulation project, or if I can get them through the nailing plates on the trusses to the double top-plates from the top I will try that when doing the baffles.

   Thanks,

   Owen

1. Expert Member
   MALCOLM TAYLOR | Nov 03, 2023 11:46am | #4

   Owen_p,

   I don't want to put words in Randy's mouth, but here is my take on what he meant:

   Some unvented roofs have no drying capacity to the underside, and some roofs are designed with a gap between the sheathing and roofing material. Both of these would benefit from a permeable underlayment, rather than being covered with a self-adhered membrane like I&WS.

   Conversely, in some very wet climates like the PNW, or where there is very good drying capacity on the underside of the sheathing, impermeable underpayments which provide a stronger defence against roof leaks may make more sense. I would put your situation in this category.

   I can't think of a situation where the underlayment being self-adhered, as opposed to mechanically fastened, is not an advantage.

3. 
   michaelcatz | Nov 13, 2023 11:22am | #5

   I'm interested in a FORTIFIED roof assembly with exterior insulation. A raised heel truss is out of the question as this is a retrofit, so unfortunately I need the more complicated assembly if I want FORTIFIED and to have a highly insulated conditioned attic in zone 2A. I find plenty of diagrams for FORTIFIED roof assemblies and diagrams for exterior roof insulation, but I have yet to come across a diagram depicting the combination. It would be great if this resource was available to bring in to form a plan or even start the conversation with a structural engineer and a roofing contractor.

1. Expert Member
   MALCOLM TAYLOR | Nov 13, 2023 11:59am | #6

   michaelcatz,

   It should be fairly easy to include all the Fortified details for a more conventional roof on one with exterior insulation. The only difference I can see is the attachment of the upper sheathing or strapping, which would benefit from a fastener schedule designed by a structural engineer.