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Construction How-To, Energy Efficiency, Waterproofing, Windows & Doors October 1, 2013 Sonia



In this two-phase project old windows are upgraded with energy-efficient vinyl replacements, plus the surrounding wood trim is protected with aluminum wrap.

By Matt Weber

 

 

 

 

 

New windows look great, save energy and require less routine maintenance, making window replacement a top project on many homeowner wish lists. The EHT staff recently participated in a window project where old, rotted wooden windows were replaced with energy-efficient vinyl units from Simonton Windows. This article chronicles the job, from pulling out the old to putting in the new.

The replacement units from Simonton not only look beautiful, but the Low-E design significantly reduces heat transfer to save on energy bills. Plus, the vinyl construction won’t require constant repainting, glazing or other associated maintenance.

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When it comes to maintenance, wooden windows require a lot. If the windows aren’t maintained with glazing, caulking and exterior-grade paint, the wood will rot. That’s what happened to eleven windows, a mix of double-hung and bay styles, on our project house. The most evident rot was along the sill of the bay windows in the front and back of the house. The lack of overhang above the windows meant that the sill was taking the full brunt of the rainfall. In fact, the sill of the single-pane bay in the front had rotted to the point that the wood could no longer support the weight of the glass.

Wood rot is caused by a fungus that thrives on dead wood in moist environments. It can wreak havoc on wood windows.

Wood rot is caused by a fungus that thrives on dead wood in moist environments. It can wreak havoc on wood windows.

The bay window actually sunk down into the rotted wood and opened a gap at the top of the frame, allowing significant airflow in and out of the home.

The solution was to remove the old window, rebuild the sill plate, then replace with a new vinyl unit. As a belt-and-suspenders approach to protection, the installers at Lifetime Windows & Doors “wrapped” the surrounding wood trim with aluminum. Here is how it’s done.

First step is to cut away all rotten wood for replacement.

First step is to cut away all rotten wood for replacement.

On some windows water intrusion had resulted in sills that were completely ruined by rot.

On some windows water intrusion had resulted in sills that were completely ruined by rot.

Benefits of Replacement

The necessary maintenance of older windows is one of the biggest complaints of homeowners, particularly of those with wood-framed windows. Painted windows require regular TLC—scraping, glazing, caulking, re-painting—to seal out the water and protect the wood from rot. New windows made with vinyl or aluminum can eliminate this hassle. The need to prevent or repair rot is one of the main reasons homeowners across America are opting for “non-wood” window replacements.

Vinyl replacement units offer smooth operation, modern decorative options and less maintenance. Unlike wood, vinyl windows and doors will never rot or require repainting. And unlike aluminum, vinyl windows and doors will never pit or flake. Today’s windows are made from the highest quality vinyl and require almost no maintenance. In fact, an occasional washing will keep them looking like new for years.

Plus, energy-efficient vinyl windows offer increased comfort and lower utility bills. New units constructed with double-paned, Low-E glass filled with harmless Argon or Krypton gas can reduce the home’s power bill in the years to come. The gasses are denser than air and serve as a thermal barrier, reducing the transfer of heat and cold through the window.

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Replacement Size

Most manufacturers will offer standard size windows, and the homeowner/contractor should order a size that most closely matches the existing units, unless they plan to change the size. Keep in mind that if a window is slightly smaller than the window frame, then it can be shimmed for a tight fit. However, if the window is too large, then it will not fit without substantial reconstruction of the wall.

This project involved same-size replacements of the existing windows. The homeowner selected Simonton’s 5500 Reflections Series. Notably, Simonton custom makes every window and door. There are no standard sizes at Simonton. Since the manufacturer customizes their windows to the exact measurements requested, the installers had no problem fitting the units onto the house.

A PVC sill replacement will resist water and rot for years to come.

A PVC sill replacement will resist water and rot for years to come.

If you’re considering replacing windows with a larger size, you should keep in mind how a window is framed. A header above the window distributes overhead weight to the framing members on each side of the window, and a sill plate on jack studs supports it from beneath. If you want to increase the width of a window, you will have to remove the wall covering and framing to reconstruct a header and sill to fit the larger width, which is substantially more complicated than a same-size replacement.

Out with the Old

Once the windows are on site, always double-check the measurements for fit before removing the existing units. The Simonton replacement units are designed to fit into the window frame and rest on the existing sill. Windows are “clamped” in place with stop molding on each side of the wall. The first step to pulling out the old windows is to remove the stops.

Stop molding surrounds the top and sides of the windows.

Stop molding surrounds the top and sides of the windows.

To remove the windows remove the stop molding along the edges.

To remove the windows remove the stop molding along the edges.

The contractors on our project used hammers, putty knives and pry bars to dislodge the old stop molding surrounding the windows on the outside of the house. With the stops gone, the wood windows could then be carefully pushed out of the frame and recycled or disposed of.

In some cases the new windows can be installed from inside the house by removing the interior stops, pulling the old window, and leaving the exterior stops in place. However, because the aluminum trim wrap would serve as the exterior stop, the installers did the reverse. They opted to remove the outer molding, leaving the inner stops in place, and install the replacement windows from outside the home.

Once the stops are removed the windows can be carefully pulled out of position.

Once the stops are removed the windows can be carefully pulled out of position.

As mentioned, some of the windows had significant rot damage, requiring not only the stops and the windows to be removed, but the sill plate to be replaced as well.

Preparing the Frame

Because of the rotted sills on some of the windows, the old wood was demolished and removed and a new sill plate made of rot-resistant PVC was leveled, shimmed and nailed to the framing.

Next, since the replacement window sits on the sill, the sill was covered with aluminum casing that was custom-fabricated by the installers to fit the new sill. (This step is optional.)

Accessory pieces such as vinyl sill extenders should be attached before installing the window.

Accessory pieces such as vinyl sill extenders should be attached before installing the window.

To help fit the window into the opening, Simonton offers accessories such as a sill extender or snap-on flange, which help conceal any gaps between the window and the house frame. These vinyl accessories are installed prior to window installation and are weather-sealed along the joint to prevent leaks.

If the window will be installed on a sloped sill, then wood blocks should be installed along the sill to help support the window and keep it level.

When installing, tilt the new window into the opening with the sash closed and locked, setting the bottom on the sill (or wooden blocks).

Because the installers were replacing the outer stop molding with aluminum casing, they opted to leave the interior stop molding in place and install the windows from the outside.

Because the installers were replacing the outer stop molding with aluminum casing, they opted to leave the interior stop molding in place and install the windows from the outside.

 

The Simonton Windows arrive with weather stripping around the perimeter of the units. This helps the window to fit snugly, and adjustments to plumb, level and square can be made with wood shims.

The Simonton Windows arrive with weather stripping around the perimeter of the units. This helps the window to fit snugly, and adjustments to plumb, level and square can be made with wood shims.

 

 

 

 

 

It’s important to remember that the replacement window must fit into the opening level, plumb and square, otherwise it won’t open/close properly and air and water could infiltrate around the edges. Check both sides for plumb. To check for square, measure both window diagonals from corner to corner to make sure they match. Adjustments to the windows fitment can be made with shims, which should be installed at all anchor points and anywhere necessary to keep the unit correctly in place.

The Simonton windows come with thick weather-stripping around their perimeter that helps the windows fit snugly. The more closely a new window fits its frame, the less shimming and adjusting will be required when installing it.

 

Seal all joints on the interior and exterior with caulk/sealant.

Seal all joints on the interior and exterior with caulk/sealant.

Once the window is correctly positioned, mount the window with the supplied screws into the prefabricated holes.

Once the window is correctly positioned, mount the window with the supplied screws into the prefabricated holes.

Once the window is plumb, level and square, drive the installation screws (provided with the window) into the prefabricated holes in the jamb. However, don’t over-tighten, or the window could bow and not function properly. Check the sash for proper operation once the screws are in place.

 

The sill of this window had rotted to the point that it no longer supported the weight of the glass. The window sank into the rotted wood, opening a gap at the top that allowed significant airflow.

The sill of this window had rotted to the point that it no longer supported the weight of the glass. The window sank into the rotted wood, opening a gap at the top that allowed significant airflow.

This bay window sill had rotted to the point that it could not support the weight of the window glass.

This bay window sill had rotted to the point that it could not support the weight of the window glass.

If any gaps greater than 1/8 inch exist between the window and frame, loosely pack insulation on the interior. Using spray foam is acceptable as long as the product is designated for “windows and doors”, meaning the foam won’t expand to the point where it could flex the window material and prevent proper operation.

 

Damon Gassaway of Lifetime Windows & Doors installs the new window sill.

Damon Gassaway of Lifetime Windows & Doors installs the new window sill.

A reciprocating saw is a handy tool for digging out the rotted wood.

A reciprocating saw is a handy tool for digging out the rotted wood.

 

 

The sill wrap is the first piece to be installed so the window can be placed over it.

The sill wrap is the first piece to be installed so the window can be placed over it.

The aluminum trim wrap is fabricated on site to match the size and shape of the wooden window trim.

The aluminum trim wrap is fabricated on site to match the size and shape of the wooden window trim.

Seal all joints on both the interior and exterior of the windows with caulk, including the holes in the jambs.

At this point, new stop molding can be installed, painted and caulked to complete the window installation. Or, as in this case, the aluminum alternative can be installed.

Large units require some assistance when installing. A worker on the inside lifts the window with a suction cup.

Large units require some assistance when installing. A worker on the inside lifts the window with a suction cup.

Aluminum Trim Wrap

The specialized equipment and required metal-crafting skills probably push this latter phase of the project outside the realm of most DIY’ers, but this method of weather protection conceals the brick mold and window sill. The wood trim is covered in overlapping aluminum casing that is fabricated on-site using a sheet-metal brake. The aluminum roll is cut to length and then bent on the brake into a profile that closely matches the window trim’s size and shape. Metal snips and hand brakes are used to adjust its final shape. The sill piece is installed first (prior to window installation) using finish nails. Next come the side pieces that shed water over the sill plate. Finally the top piece is nailed in place overlapping the sides to shed water like flashing or roof shingles. Once completely installed, all the aluminum joints and fastener holes were sealed with silicone sealant.

After the sides are wrapped, the final piece goes on top to divert water away from the building envelope.

After the sides are wrapped, the final piece goes on top to divert water away from the building envelope.

The windows are carefully measured to determine the length of the aluminum wrap.

The windows are carefully measured to determine the length of the aluminum wrap.

The aluminum wrap is available in a selection of colors to match or complement the home’s décor. The end result is “bulletproof” protection of the wood trim that surrounds the energy-efficient new vinyl windows, ensuring the entire system will stand up to weather and rot for years to come.

The finished bay window looks great and will last for years.

The finished bay window looks great and will last for years.

All seams of the window and aluminum casing are sealed with a high-quality exterior sealant.

All seams of the window and aluminum casing are sealed with a high-quality exterior sealant.