Sunday, September 17, 2006

Framing Window and Door Openings

Framing exterior walls is one of the easier tasks in homebuilding. There are still steps that should be followed to make this a smooth and trouble free operation. There is more to framing a wall than nailing some studs to a plate and standing it up.

Assumming you have laid out your plates, pull the top plate back so it is approximately eight feet from the bottom plate. This gives you room to layout your stud material to frame the wall with. If there are windows or doors in the wall, layout the headers, sills and cripples in their corresponding locations.

Window and door openings should be framed first. There is a good reason to frame these details first. When framing window and door openings, nails are driven through the sides of studs into headers, cripples, and sills. If the wall studs were to be nailed in before the openings were framed there would not be enough room to swing a hammer or use a nail gun. Even if those openings fell on 16 inch centers it would still be a little tight to swing a hammer.

The order of nailing a window opening together is also important. We'll use a standard eight foot wall as an example. In our example all the headers are 2x12. The first step is to nail the header to the top plate. The header is cut to the width of the window plus three inches to allow for the 2x4 cripples. Next, studs are nailed to both ends of the header and to the top plate using 16 penny nails. Once those are nailed in, the cripples are then nailed in. These determine the height of the window. The cripples butt up to the bottom of the header and nailed to the inside of the studs. The 16 penny nails must be put in at an angle to keep them from coming through the stud and to keep someone from catching their hand or clothing on the sharp points. The sill is then nailed to the bottoms of the cripples. The window framing is completed by adding cripple studs beneath the sill on the stud layout.

To frame a door opening the same procedure is followed except their is no sill. Studs are nailed to each end of the header and then a measurement is taken from the bottom of the header to the bottom plate. This will be the length of your cripples. These are nailed in just like the window cripples. Later on in the construction of the house and before the exterior doors are installed, the bottom plate is cut out.

Once all the openings are framed, all the wall studs can be nailed in. Make sure to follow the layout and nail everything on the right side of the line which will be indicated by an "X". Anything nailed to the wrong side of the line can be pretty obvious to the trained eye. You don't want to find this out when you are sheeting the wall.

Follow these basic rules to framing a wall and the job will go smoothly and hopefully aggravation free.

Mike Merisko (C) 2006

Saturday, September 02, 2006

Homebuilding: Raising Walls

You've just taken some plywood, 2x4 studs, 2x12 header material and some house wrap and transformed them into a wall. Its time to take the fruits of your labor and raise that wall off the deck. Having the right steps in place and making the right moves will make this task go smoothly and safely.

There are a couple of procedures that are done during the framing of the wall that play an important part in raising it. Before an exterior wall is framed, a chalk line is snapped on the deck. If it is a 2x4 wall with 1/2" sheathing, this line will be 4 inches off the edge of the deck. After the wall is framed and before any wall sheathing is nailed to it, the edge of the bottom plate is brought to the line. The end of the wall is brought to the edge of the deck. Once the frame is put in place, it is toe nailed with 8d nails on the inside of the bottom plate. Not only do these hold the wall in place when squaring up the wall, but also keep the wall on the line when raising it.

Once the wall is sheathed with plywood, insulation board, foam board and covered with house wrap you are ready to raise it. In preperation to lift the wall one must be able to get their hands under the top plate. Using a straight claw hammer or a prybar under the top plate, lift the wall high enough to slip a 2x4 flat under it. This inch and a half space gives you enough room for your hands.

If your raising a second story wall it is a good idea to nail stopping blocks to the rim joists. One of the last things you want is the wall being pushed off the edge of the deck. These are scrap pieces of lumber nailed the rim joist with 16d nails. Ideally these should be 16 to 18 inches long and nailed the full width of the joist with 4 16d nails. The balance of the board will stick up above the deck. Put these blocks at each end of the wall. On longer walls you may want to add one to the middle.

Before raising the wall, have all of your bracing material on hand. On a windy day you will want to brace the wall in place as soon as possible. Have enough braces (2x4's) to have them nailed on about every 10 feet. You will need blocks to nail to the deck to anchor the braces. These need to be about 20" long and get nailed to the deck through the plywood and into the floor joists with 16d nails. The nails need to go into the joists or ther is the risk of the bracing failing in the case of high winds.

Bracing on the ends of the walls can be nailed on before it is raised. Nail one end of a 2x4 (wall stud) about one third of the way down from the top plate, again using 16d nails. Start a nail at the other end of the 2x4 so when the wall is stood up, all one has to do is drive the nail into the rim joist to brace the end of the wall.

With all materials and safeguards in place you can now raise the wall. A good rule of thumb for raising a wall is a set of hands every 8 to 10 feet. This gives everyone a comfortable weight to lift. To save your back, use your legs in the lifting process as much as possible.

Once the wall is raised, nail off the end braces to the rim joists. Next, nail the braces to a stud or window opening about a third of the way down from the top plate, about every 8 to 10 feet apart. Next, nail the blocks to the deck alongside the braces that were just nailed the the wall, being sure to catch the floor joists with the nails. With the wall as close to plumb as possible, nail off the anchor end of the brace to the block on the deck. It is important to use 16d nails for all of these steps.

After the wall is raised and braced, the final step is to nail the bottom plate of the wall to the deck. Push or pull the wall to the chalk line that was snapped on the deck. The 8d toe nails and the stopping blocks should have kept the wall very close to this line. Once the plate is brought to the line, nail it off with 16d nails, being sure to hit either the rim joist or a floor joist. You can now walk away and start another wall.

Remember, homebuilding can be a dangerous and risky occupation or activity. Always execise caution and saftey in all aspects of the construction process.

Mike Merisko (C) 2006