Use Tyvek Over Building Felt Under Siding

The original wrb was tar paper.

Use tyvek over building felt under siding.

This product soon evolved into being made in rolls using felt then fiberglass now we are back to using paper albeit a. One disadvantage is that they can be damaged by the extractives that leach out of wet cedar and redwood siding a problem shared to a lesser extent with asphalt felt. Felt paper will absorb moisture to some degree and wick it through. We limited our tests to tyvek r wrap and felt since these were the winners of the first round of clean water tests.

The industry standard for two coat stucco underlayment at least on the west coast is two layers of grade d building paper. Tyvek has its advantages personally i prefer it to typar because it s more durable on site in my experience. Plastic housewrap is not advised for use under stucco because it reacts to the surfactants in cement plaster. Felt is preferred by some but i ve seen a lot of felt that has crumbled into dust so i prefer other things.

It s also acceptable to place one layer of grade d building paper or asphalt felt over a layer of tyvek. Who knows what tyvek typar or the random felt you get at a random supplier tomorrow will do over the next 100 years though. Another problem with using asphalt saturated felt is that it is difficult to seal the seams unlike with plastic house wraps which can be sealed with specialized tapes that are bombproof. Tyvek will not allow moisture to pass through it unless it is in vapor form essentially requiring it to evaporate before it can be transferred.

Use tyvek over building felt under siding june 1 2020amirul muncategorized this article discusses the use of roofing felt or 15 pound felt as a building house wrap or vapor barrier and the permeability moisture problems and indoor condensation problems that may occur. Tyvek and r wrap lost about 3 of the cedar extractive mix in 2 hours while felt again lost 30. Felt seemed unaffected by soap still loosing 30 of its water. Housewrap is light easy to work with and has good tear resistance.