Should I install housewrap or window flashing?
If you have a strong opinion favoring either position, it’s safe to say that either approach can work well, as long as the housewrap is properly integrated with all of the window flashing, door flashing, and the flashings protecting other penetrations. Simplifying the decision
Do you have to flash a window before taping?
Metal head-flashing may be called for by the window manufacturer. If so (or if installing a wood window), install it before taping the top flange. Flashing tape at the top should bridge the gaps between the window unit and the wall sheathing, for air sealing as well as water management.
Can flashing flashing be installed at the bottom of exterior walls?
Flashing at the bottom of exterior walls needs to be integrated into a continuous drainage plane on the exterior wall. The goal is to create a wall system that can manage the water that will inevitably get behind any cladding system.
How do you wrap around a house with exterior walls?
House wrap should be lapped over any exterior wall flashings installed around window and door openings or where roofs intersect walls. Any holes through the wall, such as for water spigots, exhaust vent outlets, HVAC line sets, or wiring for outdoor light fixtures and receptacles, should be carefully sealed or gasketed.
Does Tyvek go over or under flashing?
Always use positive shingling by installing Tyvek® WRBs and Self-Adhered Flashing products from bottom to top, with upper layer installed over lower layer.
Does house wrap go over window flashing?
The house wrap has to be flashed properly to keep the water moving down and out, not down and in. That means you want the upper layers to come down over the top of the lower layers. Where builders often get this wrong is at the top of a window.
Does house wrap go over roof flashing?
Per Building America guidance, house wrap should be lapped shingle style over any exterior wall flashings installed around openings, penetrations, or where the walls intersect roofs, foundations, or other transitions.
Does window flashing go over Tyvek?
Avoid placing DuPont™ Tyvek® Wrap Caps where flashing will be installed; however, DuPont™ Tyvek® Wrap Caps can be applied over the flashing.
How do you install house wrap and window flashing?
0:376:05How to Install House Wrap & Window Flashing - YouTubeYouTubeStart of suggested clipEnd of suggested clipMake your first cut horizontally. Along the top of the window. Once. This is complete make two 45-MoreMake your first cut horizontally. Along the top of the window. Once. This is complete make two 45-degree cuts on each side of the header on top of the opening. And fold the newly created flap upward.
How do you install flashing around a window?
7:428:44How To Properly Flash a Window - YouTubeYouTubeStart of suggested clipEnd of suggested clipProvide a weep area to allow moisture to find its way out at the window head cut and fold the homeMoreProvide a weep area to allow moisture to find its way out at the window head cut and fold the home wrap out of the way and make sure that the head flashing adheres. Directly to the ceiling.
Should flashing be visible on roof?
Roof Flashing Is Not Always Visible: While some areas are exposed and fairly obvious, like where shingle meets brick, others may be hidden behind siding or other roofing materials. It is always a good idea to hire professional. They can better identify if your roof flashing needs work.
Should roof flashing be exposed?
The flashing should be partially exposed along the wall. Since you can see step flashing, some homeowners choose a more expensive flashing material like copper to achieve a certain aesthetic.
How many layers of house wrap do I need?
two layersThe building code requires two layers, or equivalent, over wood-based sheathings when the cladding is a cementitious product; however, many consultants still advise that two layers are the best practice, even when not applied over wood-based sheathings.
Do windows go in before or after sheathing?
A window is installed on a stud wall with sheathing after the building wrap is in place. It is then attached using the nailing fin and integrated with the building wrap using flashing tape.
Can you install house wrap after windows?
If you don't shingle the materials so that they shed water away from materials that are susceptible to moisture damage, you make it more likely that water will get in. Installing the house wrap after the windows means that it's impossible to shingle it properly.
Should you caulk window flashing?
Another place that should never be caulked is the space between the siding and the flashing above a window; this piece of flashing is often referred to as drip flashing, drip cap, or head flashing. Caulking this opening shut is a very common defect, even on new construction.
How do you Tyvek around an existing window?
On both sides of the window or door, trim the wrap close to the window or door flange. Secure the wrap to the flange with tape or caulk. Install side flashing over the wrap. Install head flashing and extend out 3-4 inch to each side.
Do you wrap windows before or after siding?
Installing the windows first allows the contractor to set them into place and then precisely finish off all the capping surrounding the windows before adding the siding. Window capping is a protective covering, usually aluminum, that is often added to exposed exterior frames during the installation.
Do windows go in before or after sheathing?
A window is installed on a stud wall with sheathing after the building wrap is in place. It is then attached using the nailing fin and integrated with the building wrap using flashing tape.
Is window flashing tape necessary?
Flashing is an essential component of proper window installation. It catches rain that is blown at an angle onto your home. Siding isn't enough protection between your house and the rain and moisture that occurs outdoors, which is why you need to put an extra barrier between your window and siding.
Why is flashing important?
Properly installed wall flashing is critical to your building’s health. Many builders and designers believe that inadequate vapor barriers are the main cause of moisture problems and wood decay in walls. However, the vast majority of water problems in walls are caused by water leakage from the exterior — not by poor vapor barriers.
Why do we need membrane flashing?
Membrane flashing was retrofitted here to protect the ledger and wall framing from water intrusion.
What is step flashing?
STEP FLASHING. All flashings must integrate with adjacent materials, so water always flows to the exterior, following the shingle principle. Where a slope roof meets a sidewall, slip the upper legs of the step flashing under the sheathing wrap (see Illustration).
How wide is a flashing membrane?
In wall areas frequented wetted by splashing rain (splashback) or snow buildup, flashing membranes up to 36 inches wide can be used to protect the wall sheathing and structure. Water damage from splashback is common in wall areas located:
How far should a water table extend over a house?
CLICK TO ENLARGE Many traditional homes have a wide board, called a water table, along the top of the foundation. The water table should extend about an inch over the foundation, and be protected by a metal drip cap tucked under the housewrap or building paper.
How far should a termite shield be above a foundation?
Termite shields should be at least 6 in . above grade and extend out 2 in. on either side of the foundation downward at 45 degrees. In addition to making infestations visible, termite shields also form a capillary break between the foundation and sill, protecting the sill from moisture. Trouble spots.
Where to install flashing on a house?
Install flashing under the bottom edge of the house wrap or other weather-resistant barrier shingle fashion to direct water out of the wall.
What is flashing at the bottom of exterior walls?
Flashing at the bottom of exterior walls needs to be integrated into a continuous drainage plane on the exterior wall. The goal is to create a wall system that can manage the water that will inevitably get behind any cladding system.
What is flashing on plywood?
Self-adhesive flashing. When the weep screed attaches to plywood, OSB, or another wood-based framing material, a self-adhesive flashing membrane is needed first to protect the wood from water draining through the perforated screed ( EPA 2015 ).
What is through wall flashing made of?
Through-wall flashing can be made with metal, but is usually formed with a flexible rubber-based membrane, such as the one shown in Figure 8 ( Hanley-Wood 2007 ).
How many inches should flashing be on a wall?
When more than one length is needed to span across the bottom of a wall, overlap pieces at least 8 inches. The flashing must include a drip-edge to direct any water that runs down the drainage plane away from the bottom of the wall. Weather-resistive barrier.
How far above grade should flashing be?
To prevent splash back from the roofline soaking the base of the wall, the bottom edge of the base flashing should be at least 8 inches above grade. This is a design detail that must be worked out before the foundation is poured.
What is the transition between different claddings?
transitions between different claddings when more than one cladding is used at the bottoms of exterior walls where cladding systems interface with the foundation. The key to eliminating costly leaks is more than just applying a piece of flashing.
Why do you need to wrap your house?
House wrap matters because siding materials leak —brick, stone, wood, EIFS, vinyl—house wrap has to protect the structure from the siding leaks. Siding doesn't leak because it is bad, siding leaks because people install it. BOWA's advice: Because siding will leak, add a backup layer to collect and drain the rainwater.
What is through flashing in siding?
Through-flashings are important for masonry, such as brick or stone, but can be incorporated into wood siding, too—a flap of house wrap between two courses of siding directs water out as quickly as possible. This detail can also be seen in Window Retrofit: From the R.O., Out
How to make a WRB flap?
Cut the WRB Flush. Cut the house wrap flush—or even up to 1 inch past—all sides of the window . Cut 45 degrees extending outward from the top corners to create a flap that allows you to tuck the top flange of the window behind the WRB.
How many staples per 9 feet of house wrap?
Fasteners: use a cap nailer because slap staples leak. Tyvek says you can use 4 staples per 9 feet of house wrap if you tape over them an apply the siding right away. But a cap stapler is better. Apply house wrap up the gables before installing exterior trim, even if the attic is not conditioned.
How to make a roof that doesn't leak?
Step by step to roof/wall connections that don't leak: Wrap roof paper up the wall to backup the step flashing. Five inches up the wall is good for 4-inch step flashing. It should be high enough for visual verification that it was done. Cut the house wrap so that the roof paper can be tucked underneath.
What is the skirt called for flashing?
Before installing pan flashing, install a skirt to extend the sill pan through any masonry siding. This skirt is called through-wall flashing.
How to pour water into a taped seam?
" A great way to pour water into a taped seam is to tape halfway up a button-cap fastener. We train people to hold the fasteners up away from the seams, and to tape over any such caps."
Why does housewrap belong between foam and strapping?
For example, I’ve heard that the housewrap belongs between the foam and the strapping, “because that way it’s easier to integrate with the flashing at the logical drainage plane.”
What is the purpose of housewrap under foam board?
The purpose of housewrap under the foam board is to provide a drain plane for managing bulk water being directed to that layer by the window flashing. This is sometimes referred to is "innie" mounted windows.
Do you put housewrap over foam?
If you are installing “outie” windows, your housewrap should go over the foam.
Does foam wall sheathing dry out?
Walls with exterior foam are designed to dry to the interior, not the exterior -- but they only work if the rigid foam is thick enough to keep the sheathing above the dew point during the winter. For more information on these issues, see Calculating the Minimum Thickness of Rigid Foam Sheathing.
Can you put felt under a wall?
You say under, I say over. It’s possible to install housewrap or asphalt felt between the wall sheathing and a layer of exterior foam, as shown in this detail. It's also possible to install the WRB on the exterior side of the foam.
Can you put polyiso on the outside of a wall?
If polyiso makes you nervous, there's nothing wrong with installing EPS on the outside of your wall sheathing. (I did that on my own house.)
Does permeability matter in house wrap?
A. The permeability of the foam or the housewrap doesn't matter much, because such walls are designed to dry to the interior, not the exterior.
What does flashing a window mean?
Flashing as a noun refers to the strips of membrane applied to the perimeter of the window. Flashing as a verb is the act of placing those strips of membrane around the window with the intent of keeping water out of the building.
Is window flashing necessary?
Flashing is an essential component of proper window installation. It catches rain that is blown at an angle onto your home. Siding isn't enough protection between your house and the rain and moisture that occurs outdoors, which is why you need to put an extra barrier between your window and siding.
What is window flashing made of?
Sheet metal varieties are widely used and include aluminum, copper, zinc, and galvanized and stainless steel among others. Vinyl flashing is also called PVC flashing and is quite inexpensive. Tape flashing, also called self-adhering membrane, is the newest form of window flashing.
Does flashing go over or under house wrap?
The house wrap has to be flashed properly to keep the water moving down and out, not down and in. That means you want the upper layers to come down over the top of the lower layers. Where builders often get this wrong is at the top of a window.
How do you apply flashing?
Step One: Install shingles as normal up to the base of the plumbing vent.
How much does it cost to replace window flashing?
Window Flashing Repair Cost Window flashing repair costs $400, with the majority of homeowners spending between $300 and $500. Oftentimes, window flashing repair involves fixed skylights that are leaking, so you might also have to add the cost to repair water damage to the interior of your home.
Do all windows need a drip cap?
Do you need the window drip cap? The short answer is, yes. Without the window drip cap installed around your window, the water will either seep into your home and leak all around your window or it will seep into the middle of your double-paned windows. Neither of these options are good ones.
Is waterproofing a common subject?
I’ve seen a LOT of windows/doors flashed the wrong way, which is one reason waterproofing is a common subject on forum s and in publications.
Do you need to flash metal cap on stucco?
We rarely installed door or window cap metal flashing at that time. Most of our exterior wall finish is stucco. Stucco isn’t proud of the window/door trim, it’s flush, so metal cap flashing weren’t considered necessary. Today, like most window/door manufacturers, I’d suggest, installing that flashing on stucco walls, too, at the top of the window (you can’t install it at the top of the stucco molding). And I’d definitely install a metal cap above any trim that’s proud of the siding (yes, that means making an angled cut through the housewrap at both ends of the TRIM, installing the flashing, installing a self-adhesive membrane on top of the flashing that extends beyond the cut in the housewrap, then folding the housewrap back down on top of the membrane and flashing).
