Window Installation 101- Step 3

It may not actually be the 3rd step, but it is the 3rd installment of the "how-to". So... here it goes:

We are ready for window installation. The hole is prepped & flashed, checked for level & square, & you should have verified that the window you are going to install fits in the opening with approximately 1/4" to spare all the way around. In new construction when dealing with vinyl windows the opening is called out on the plans as the size the opening is supposed to be framed at. The windows ordered should arrive 1/2" shorter in the height & length. So a 5/0X4/6 will actually be 59 1/2" wide & 53 1/2" tall. (Also, the opening is referred to in ways: casement= hinged from a side, awning= hinged at the top, single-hung= sliding up, double-hung= sliding up or down, & x/0= sliding from left to right if looking @ it from the outside... the 'x' represents the operable part & the '0' represents the fixed)

Place carpenter's pencils in the bottom corners & about every 2 or 3 feet on the sill. The window will rest on these during installation, ensuring a gap at the bottom of the window which helps with potential water having an escape route as well as ensuring the window room for movement as the house/addition settles over the first year.

Now, apply a continuous bead of caulk @ the sides & top of the opening. DO NOT APPLY TO THE BOTTOM! This again allows for an evacuation route for any potential water intrusion from above. We are directing it where we want it to go. Outside & down the wall, on-top of the vapor retarder.

We have a 1/6X2/0 single hung window. Remove the screen if there is one, & make sure the window is locked closed. Working from the outside, place the window into the opening on top of the pencils or shims (verify that the weep-holes are on the outside & at the bottom). If you are working alone, slide it to the right, make mark, then slide it to the left. Now, split the difference between the two spots & slide the window to roughly centered.

Take a 2" galvanized roofing nail & drive it into one of the bottom corner holes in the window fin. Don't drive it all the way, in-case adjustment is needed.

Check for level & adjust if needed. This will help to ensure proper function of the operable parts. Tack the window in place, unlock it, & check for proper function. If all is well, fill every other hole in the fin along the sides and bottom, leaving the top alone. At the top, install the nails above the fin about 1/2" and drive part-way, bending them over to hold the window in position while allowing for potential movement in the framing.

You are now ready for vapor retarder & more flashing.

Window Installation 101- Step 2

I have found that different products stand up under pressure in different ways. Some products in the construction industry have been around for 100 years & longer, while some are still under development. As a general rule, I opt for good-old-fashioned-tried-&-true things. Window flashing is an area that has changed almost daily since the advent of "double-paned aluminum" windows w/an integrated installation fin. This has made product knowledge invaluable, & difficult to stay on top of, but I try. Basically I have found the old saying: "Everything is not created equal" to be true. As a general rule, you also get what you pay for. The products I am showing aren't the only ones on the market. I even know of a couple that might out-perform, but the Fortifiber line is among the best @ innovation & quality, while remaining readily available and affordable.

Caulking is placed @ the bottom corners (a healthy bead @ approximately 1/4"). I choose Moistop here and a couple other places due to it's excellent adhesion to vinyl windows & other flashing materials.

Then, place the corner shields @ the bottom corners. These are another product that I believe is money well spent. Again, they

are manufactured by Fortifiber.

Next, place a strip of at least 6" butyl based flashing membrane. I like the FortiFlash, but several manufacturers make quality products. I look for good flexibility & adhesion. Some other options are: BlueSkin, Grace, & WetFlash. Make sure that the inside will wrap onto the flat portion of the sill past where the inside of the window will be (if you keep it in 2" or more, it should be adequate.

Continue applying the flashing membrane. The idea, with all exterior weather-proofing systems, is "shingling". Think of bird feathers or fish scales. Always overlay & work from the bottom up. The outer-most layer will be @ the top, always. Whether you are laying roof shingles, horizontal plank siding, or flashing in a window. So, think like water & layer things starting at the bottom.

The pictures should give a good idea of what the product will look like at the stage we are at. If it seems redundant, complicated, or over-technical; it is. But that is what keeps the weather were it should stay, out-side.

Next: Actually Installing the Window!

Window Installation 101

Windows, while adding much to the outward appearance of a home as well as providing needed ventilation & natural light inside, provide a set of challenges that often remain overlooked in the exterior cladding of a home. I have spent some time installing windows & over-seeing window installation, & correcting poor window installation. So, I recently found myself working on a small remodel/addition with one window needing installation. I decided this would be an excellent opportunity to show a couple pointers & techniques that we employ to ensure a weather-tight building envelope & give the customer a lifetime of service.