A water-managed window installation properly weatherlaps and integrates the window unit and the rough opening flashings and weather-resistive barrier (WRB). It is appropriate for moderate to high weather exposure. In this 14-step installation series, the window unit goes in before the WRB (housewrap) goes up.
S 2//Flanged window installation // water managed // housewrap//Step 2
Details that show the complete and final configuration of window installations are fine, but window installation step-by-step series are where the rubber meets the road.
Note that either tape or membrane flashing covers the metal window cap flashing. The interior flashing or tape covers the window flange so that wind-blown rain that gets up underneath the metal window cap cannot get behind the window flange. The weatherlapped exterior membrane flashing or tape handles water running down the weather-resistive barrier (WRB) to the window.
Air sealing between the window unit and rough opening at window sills is a tough detail. You don't want the air sealing material to trap water or restrict water from draining out, but you also don't want air leaking in at the sill.
The best approach is to still use expanding foam at the sill but keep this bead as far back to the interior as you can. The detail shows the foam bead right at the inside edge of window unit. That is the best placement.
Sometimes is seems as though "stick and peel" is a better term for these membranes than "peel and stick." It's important to investigate the compatibility of the self-adhered membrane with the substrate (the material to which you are applying the membrane) BEFORE using it at the job site. Most manufacturers suggest priming the substrate, if conditions — dirt, moisture, temperature (pretty much just regular job-site conditions) — require. So, priming is a really good step to add with self-adhered membranes, given that the primer works okay with the substrate. Another approach is to back up the membrane's adhesion with strategically placed fasteners.
There are two types of low-e coatings: soft-coat (sputtered) and hard-coat (or pyrolytic) coatings. The type of coating can affect other window properties, such as how well it blocks heat from the sun (called solar heat gain coefficient(SHGC) The fraction of solar gain admitted through a window, expressed as a number between 0 and 1., or SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.) or how much light it allows (visual transmittance, or VT). Double-glazed or triple-glazed low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. windows can be ordered with either a low SHGC or a high SHGC. In most climates, south-facing windows should have high SHGC glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill., while west (and in some cases east) windows should have low SHGC glazing.
Certain low-e coatings can give windows a bluish or reddish tint, most noticeable when looking at the glass from an angle. Since everyone has their own sensitivity to color filtering, it is best to discuss the issue with your clients and make sure they see and approve of the window selection.
For more information on low-e coatings:
For the best overall information on residential window properties:
Efficient Windows Collaborative.
For product information on high-performance windows:
Green Building Advisor.
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