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.

Use tyvek over building felt under siding.

While some believe that the original product was made from cotton rags or felt the original was made generally from squares of paper way back in the 1800 s used during the gold rush period even on the prairies for shanties roofing. 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. 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.

Felt is preferred by some but i ve seen a lot of felt that has crumbled into dust so i prefer other things. Felt paper will absorb moisture to some degree and wick it through. 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.

Housewrap is light easy to work with and has good tear resistance. Tyvek and r wrap lost about 3 of the cedar extractive mix in 2 hours while felt again lost 30. Plastic housewrap is not advised for use under stucco because it reacts to the surfactants in cement plaster. Tyvek and r wrap lost about 10 of the soapy water column in 2 hours.

The original wrb was tar paper. Felt seemed unaffected by soap still loosing 30 of its water. Who knows what tyvek typar or the random felt you get at a random supplier tomorrow will do over the next 100 years though. It is also much heavier than house wraps that are made from thin light weight plastic fabrics such as polyethylene tyvek and polypropylene typar.