But it is also vapor permeable to allow water vapor to escape when it does get into walls.
Purpose of tyvek with concrete siding.
Layering tyvek probably won t cause any adverse conditions of any type.
On all walls and all exposure conditions there were large areas of the tyvek which were deteriorated to the point of tissue paper.
A wind can blow and not get through even if it is carrying rain or snow.
Air seal strategies using tyvek and similar housewrap products to save building energy costs for heating or cooling estimates of before and after building air leaks and air changes per hour for older homes estimates of cost savings from sealing air leaks other indoor air quality problems that may occur when air leaks are sealed table shows relative importance of various building air leaks questions answers about best details for installing housewrap at building sills soles and top plates.
In this case the tyvek simply acts as a bond break allows the materials to move easier.
Dupont the manufacturer of tyvek recommends using a dupont approved primer for this purpose such as the following.
It can be installed behind exterior claddings such as stucco stone veneer brick wood and fiber cement lap siding or metal panel systems.
Tyvek is not a vapor barrier not that it matters its only purpose is to repel water which finds its way under the siding and to reduce wind infiltration on crappily constructed frame structures.
Tyvek is the brand of house wrap manufactured by dupont and its purpose is to protect your home from weather in general and moisture in particular.
Moderate to high vapor permeability helps to promote drying in wall systems to prevent the formation of mildew and mold.
As a result it can contribute to improved building durability by helping to protect homes against damaging wind and rain that can penetrate the exterior cladding.
Improves indoor air quality.
Apply primer if the sill is made from concrete masonry or fiber faced exterior gypsum board.
Dupont tyvek homewrap is the original house wrap incorporating unique material science that helps keep air and water out while letting water vapor escape.
Dupont tyvek drainwrap is durable and maintains a constant drainage rate even after repeated wetting and drying cycles helping to protect the wall cavity from water that gets behind the cladding.
With that said the best place is dependent on where you install the windows.
Tyvek drainvent is a patent pending three dimensional honeycomb textured drainage mat with attached heavy duty filter fabric that creates a space for water drainage and air movement behind cladding.
Advantages a building envelope can provide include protection against water damage improved energy efficiency increased comfort and reduced building maintenance.
Called a weather barrier tyvek has a unique venting system almost like a door that swings only one way.
If they are mounted in the cavity or attached to the sheathing the foam should be over the wrb which is integrated with the window flashing.
Primer is only necessary in areas of severe weather conditions severe cold temperatures or certain building materials.
Tyvek can reduce air and water infiltration to help prevent drafts and water damage.