Monday, September 3, 2012

Wild West Window Installation

Wild West Window Installation - How To Install A Vinyl Window Now you may think you know how to install a window. Chances are... you don't. You might be asking yourself; "Why would this guy know more than I do?". Trust me, most installers who have been installing windows for 20 years have no idea how to properly install a window. Yeah right! What makes you such an expert? Well to start with I'm a Certified Window Installer. I was until a few months ago the Inspector for the Siding and Window Dealers Association of Canada in Calgary. I was often referred to as "the Association's best inspector" I don't know if that was true, but I heard it many times. The reason I left the association was that I was unhappy that the Association would not enforce their own rules, making my work useless. I started building houses in 1982 and have built all the windows and doors in my own house out of oak. I know windows. Manufacturers sell windows with nailing fins. These nailing fins are commonly used to hold the window in place without any other support. As I have described in a previous article, this is wrong. There's a very important document titled CSA A440.4-07. This is the correct method of installing a window. Now, it's 114 pages long and I'm not going to try to cover everything in this article. Is it required by the Building Code? Yes, at least in Alberta and I suspect everywhere else in Canada. Article 5.10.1.1. Environmental Separation of the Alberta Code lists this CSA Standard. The Standard itself states that it is supplemental to any Manufacturers' Installation Instructions. That means that whatever the manufacturers' instructions are, you still have to comply with this Standard. Are Installers complying with the Standard? No. I estimate that more than 90% of the windows installed do not comply with the Standard. That includes new homes and renovations. So if you've just had windows installed, chances are they're installed wrong. If the odds were that good in Vegas, my money would be on the table. "My widows work fine! They look great and the Installer cleaned up nicely when he was done. What's the difference?" The difference is durability. If you were to put new windows in your house the bill would probably exceed $10,000. 00, larger houses would be more. How long would you like those windows to last? If the window is not supported properly, the window will sag and shift. Most windows today are made of vinyl, the vinyl will only take so much stress. As the window sags, the frame will crack, or the glass may break. Recently, I inspected a new home. I opened a casement window and found that I could not close it. The frame had sagged and the window no longer fit the frame. This was brand new! I thought that the window could be re-installed, but after talking to the Manufacturer's Rep. I learned that the window could not be salvaged and would have to be replaced. The Manufacturer was supplying the window free of charge to the Builder, because they didn't want to lose the Builder as a customer. If widows are not installed properly they will fail prematurely, how prematurely will depend on how badly they were installed. As I stated earlier, I can't hope to give you everything in the 114 page document that is CSA A440.4-07. I'm going to try to narrow it down. Most widows are vinyl, most windows are sliders and most window replacements are complete tear outs rather than installed inside the old frame. This should be fairly manageable. There are differences with different materials and types of window, so don't try to extrapolate. Step 1: Ordering Your Windows Take off the casings (moldings) surrounding the windows. If you think you can measure the window without taking the casing off, you are wrong. You have no idea what the previous installer did. The existing window could be too large and is forced in or too small. I know of one young renovator who got stuck with the task of installing windows that his dad ordered. Dad didn't measure very well and all the windows were too big for the rough openings. He couldn't return them. If it wasn't his dad he could have just said no. The thought of that job makes me cringe. Measure the diagonals and make sure the rough opening is square. You want the new windows to be approximately 1 inch smaller in both dimensions than the rough opening. That will give you approximately ½" all around the window for shims. If the openings are not square, as determined by measuring the diagonals, you might want to make the windows a little smaller, because you want the window square. The supplier will want to know if the wall is 2x6 or 2x4. You'll also want to decide if you want a "brick molding" or not on the exterior. You'll have to figure out how big the brick molding should be and compare that to what is available from the manufacturer, and adjust from there. If you want my opinion order the windows without a nailing fin. Step 2: Removal of the Old Windows Once the new windows arrive, inspect them. First check the new windows and make sure there is no damage and that they are the right size. You don't want to find that out once you've removed the old window. The idea here is to remove the old windows with as little damage to the house as possible. That means you have to put the sledge hammer away. Cut any caulking, that way it won't be a problem, and it can be a problem. If you can find fasteners, remove them. Sometimes there are nails through the brick molding or screws through the frame or nails in the nailing fin. You'll only find the nailing fin if you remove the trim or siding around the window. If you are dealing with stucco or synthetic stucco and there is no trim around the window, cut the fin off and leave the fin there. Once you've removed all the fasteners you can find, it's time to remove the old window. Again, no sledge hammer. The window will probably be difficult to move, but it should be loose everywhere. You can use a hacksaw blade to run around the window, there may be some fasteners that you were not able to find. You can use a reciprocating saw to cut any fasteners in the gap, but do it gently. Remove the sashes (operating windows) and try to remove the fixed panes without breaking them. I usually use a small pry bar with a wide blade. If the window won't just slide out with some gentle tapping, I usually cut through the bottom of the frame around the middle and pry the two halves up. I can usually remove the other frame pieces easily from there. Try to put as little stress on the building as possible. Step 3: Cleanup & Preparing the Hole At this point you want to examine the framing around the window opening. Any wood that is rotted should be replaced. That's easy to say. It's sometimes tricky to remove the wood, replace it and keep the strength of the structure intact. If there is just some mould, spray it down with some bleach and move on. The building paper probably got mangled when you were removing the window. Trim it back and repaper as best you can. The purpose is to protect the wood. You can use a peel and stick product, it works really well. You are limited though, because in some cases the siding is still in place. Remember that higher pieces overlap lower pieces. Water runs downhill... usually. Start at the bottom and work your way up. There are lots of diagrams to show you how to get this right. The bottom sill piece is made longer than the hole and cut so that it folds up the sides of the hole, and hopefully there's a little room below the hole so the piece can fold onto the exterior sheathing and run past the hole on either side. The side pieces should be cut so they fold onto the bottom of the hole and fold onto the sheathing. The extension of this piece should overlap the bottom piece. The top piece is a little trickier. It should tuck under the paper above the window if possible and be cut and folded as the other pieces. The point is to restrict water entry and protect the wood framing. There is a good diagram available on the internet. Step 4: Installing the Window Place two sets of shims about a 1/2 inch thick on the rough sill and check for level. I say two sets because shims should be used in pairs, assuming that the framing is relatively straight, and it often isn't. Rough sills are rarely level and you will have to adjust your shims to get a level surface to rest the window on. While someone holds the window in place for you, get the bottom frame member of the window level. Drill holes through the side frame pieces about eight inches down from the top of the window and run screws in to hold it in place, not tight. Alternatively, you can drive nails in on each side of the window. You're just trying to stop it from falling out while you are working on it. You will have to add shims at strategic points under the bottom frame member. These shims are critical to the durability of the window. Without them the window will sag. You need a shim set under each vertical member of the window. You will also need a shim set under the quarter points of any fixed pane unit. Measure the width of the fixed pane, let's say it is 24" wide. Divide by 4, that gives us 6". Measure that distance in from each end. You need shims there. You're probably wondering why. The manufacturer supports the glass in the frame at those points. If there is no shim under it, the weight of the glass will warp the frame downward at those points. I've seen it many times. Once these points are taken care of, check to see if there is more than 16" between any of the shims. Install additional shims as needed to reduce the spacing to 16" or less. Make sure the bottom is level. On a slider you can just about put your level away at this point. If the bottom is level, it's just a matter of making the window fit properly. Open the window, just a bit so you have a very small space between the sash and the frame. Use shims to adjust the frame until that space is even from top to bottom. Work from the bottom up. First shim set goes at 8 inches up. Now the Standard says you don't have to fasten the shim in place. If you don't the shim becomes useless once the insulation is installed. The frame will bow in. If you run a screw through the shim as is suggested but not required in the Standard, the window frame is trapped between the screw head and the shim. It's not going anywhere. Shim sets (and screws) should be placed every 24" up the side of the window and 8" from the top. You're probably wondering why 8" from the top and 8" from the bottom. Vinyl expands with heat. If we put the shim too close to the corner. The vinyl expanding sideways will have nowhere to go. It will either bow or break. We don't want either one to happen. When the shim is 8" from the corner, the vinyl can expand and the shim is close enough to coax the window back to the original location when it cools. There are no shims in the top of the window, unless it's a big window and it is sagging. Once you're happy with the installation, cut your shims off slightly back from flush on the inside and outside. Step 5: Insulating Use polyurethane expanding foam that expands a little. Leave the 3X expanding foam on the shelf. Install the expanding foam sparingly. If you use too much foam you'll distort the window forcing the frame inward. You can see why, if you haven't used any screws to fasten the shims in place, the shims become useless. Use the minimum amount of material. Start with a layer at the exterior, about a half inch deep and wide enough when expanded to fill the gap between the window and the building paper you installed earlier. If there is a brick molding installed, you will have to install this from the inside. Then do the same on the inside. You want the foam to bulge out a little and contact the vapour barrier. You now have 2 layers of insulation and a dead air space between them and a continuous vapour barrier. Once the foam has set up, trim it off flush with the drywall. The ends of your shims should pretty much flush with the expanding foam at this point and they will allow air passage, so caulk the ends of them to seal them on the interior. Install casings on the interior and caulk the joints. Install casings on the outside if you don't have brick moldings and caulk the joints there. There's a lot of detail that I haven't covered, such as type of screws, dimension I and quality of shims. There are also solutions to a number of problems you can encounter along the way. If you are an installer, you know what I mean. It's not just a matter of going down to the building supply store and sticking the windows in on the weekend. If the thought of installing your own windows scares you, that's a good place to start. Learn as much as you can before you start and be careful at every stage. Like I said most professional installers are doing it wrong, so your chances of of doing a better job are good. If you have no tools and you've never tackled a renovation job though, you might want to skip this one.

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