Published on June 1st, 2013 | by Henri0
House wrap and rain screen for old house
Q. I read you faithfully and love to use your advice as documentation for my thoughts on taking care of old houses, especially with sons-in-law!
We are rehabbing a 100-year-old gable-and-wing Maine house as a family retreat. It has never had central heat or proper plumbing. It is well-sited on a slight rise without trees too close, which is why it has survived 30 ± years of neglect. We have had to remove two sides of clapboards that had become too worn to save.
Our contractor wants to cover the sheathing in Tyvek but I would prefer felt paper. We are insulating with a proper vapor barrier to the inside and have installed soffit and ridge vents to ventilate the new roof. I am not convinced that Tyvek “breathes” like felt paper. Am I wrong?
A. On an old farmhouse that most likely has board sheathing instead of plywood, using a housewrap is not a bad idea because it will be an air barrier, which is a great help in energy efficiency. However, I would advise you to seriously consider the rain screen that I developed over 35 years ago. It really helps prevent clapboard problems.
You can easily provide a rain screen by using Benjamin Obdyke Home Slicker with Typar. You get a housewrap and the rain screen in one operation.
You can get all the details at www.benjaminobdyke.com and click on Wall Products, Rain screens, Home Slicker plus Typar. What this system provides is an air barrier, a breathing vapor membrane and a drainage plane/air space for the wood siding to dry.by