Tyvek, Felt or ?? Under cedar shingles
Hello everyone, I am glad I found this forum.
We’ve just purchased a 140 year old house in Western Head, Nova Scotia. One project that’s needed is to replace the ageing cedar shingles on the exterior walls.
That, thankfully, is well within my skills set.
I was reading this post from about ten years back:
https://www.greenbuildingadvisor.com/question/building-felt-vs-house-wrap-white-cedar-sidewall
I’m wondering how that advice might have changed in the last decade.
The house in question is on the edge of the Atlantic, so we’re talking cold winters, and a lot of heavy rain and wind. I don’t mind doing the work, and don’t mind spending the money, but want the job done right.
Any and all advice is welcome.
Barry
I’ll add, while we don’t mind spending the money, budget does matter. And while I don’t mind doing the work (we’ve been quoted $50k for shingles and tar paper) I also have a real life.
Also,if Antarctica falls into the ocean and melts, the house will float away anyhow…
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Replies
Barry,
Benjamin Obdyke has a few nice products that I would consider using here. Here's the product listings -
https://benjaminobdyke.com/product/slicker-hp-rainscreen/
https://benjaminobdyke.com/wp-content/uploads/2019/05/RainscreenSystem-Brochure_2022-Web.pdf
The Slicker HP has the cedar mesh and house wrap all in one, it might save some labor compared to other products.
Wouldn't HydroGap work here as well? 2 for 1 application? House wrap and rain screen?
https://benjaminobdyke.com/product-systems/system-drainable-housewrap/
Wow, beauty house.
In that wet, wind driven rain climate, protecting your walls is critical. If you are taking off all the siding it will be a good time to check the envelope system as a whole, including penetrations like windows and doors, flashings, etc.
A rain screen is highly recommended as this makes a very high performing wall in wet climate.
You will want a good second plane of protection (WRB) under the siding, and you will have the opportunity to detail this as an air barrier, which will make your house more energy efficient.
If it were my house, it would look like this: Sealed WRB, vertical rain screen, horizontal strapping, cedar shingles.
Some of the other folk on here are from climates with wind driven rain and may have more insight.
OK, Google fails me, what exactly is an WRB?
Appalbarry,
A WRB (weather resistant barrier) is the felt of house-wrap.
Aha! Obvious once you know it!
I get stumped by initialisms here all the time.
I would probably use a high-performance, self-adhering WRB such as those sold by Pro Clima, Siga and Rothoblaas. And a separate rain screen product that allows drainage and drying, not just drainage, such as Obdyke's Slicker Classic.
I would also consider this a good opportunity to add continuous exterior insulation--you won't get another chance for a long time!
Check with your local building inspector. I live part of the year in a similar climate (Buzzard's Bay) and they're pretty fussy about how cedar shingles are applied -- stainless nails, Vycor on the corners are a few details I remember from the last time. It's been a while but I think they may now require horizontal strapping or rainscreen over the WRB.
If you're residing I would also look into adding exterior insulation.