Thursday, February 6, 2014

How to properly frame an exterior wall with doors and windows in it

How to properly frame an exterior wall with doors and windows in it

Framing a house part 2

In part one; I explained how to properly frame an exterior stud wall that had no doors and windows in it. In part two; I will explain how to frame that same stud wall when you have to account for doors and windows. To properly understand the basics and the terminology it is recommended that you read part 1 (posted 1/3/14) first to understand some of the things I will be talking about in part 2.

You need to start by taking your bottom and upper plates and cutting them to the appropriate length, then turn them on their edges and place them together just like you did when framing a simple wall. Once you have the plates together and lined up you can start the layout process for the wall.

To properly layout a wall that has windows and doors in it you need to start by laying out where in the wall the windows and doors will go. To do this you will need to get all your measurements from the house plans.
When reading house plans to discover where the doors and windows are to go you need to check several

1. The floor layout, it will be a top down view of the floor that you will be framing. This view will show you where in the wall the doors and windows will be located.

2. The elevations. The elevations are the picture of the house from the outside. Turn to the view that shows the side that has the wall that you want to frame. You need to measure the height of the windows off the floor. This is important, this is the only way for you to discover at what height your windows will be placed at.

3. Turn to the window and door schedule. This will tell you the size and shape of the windows and doors that are to be installed in your wall.

Once you have the measurements you will need to add between 1 and 1.5 inches to each measurement, this will allow you to properly level, shim and insulate the window at a later date.

Back to the laying out of the wall plates;

Start from one end and measure out the distance to wear the centre of each window and door will go. Make a centre mark and if it helps you can write window or door there to remind you. From the centre mark go an equal distance each way so that you have the edges of the windows and doors marked with the extra 1.5 inches included. Take your framing square and mark these with a straight line. A framing square has one side that is exactly the width of a stud 1.5 inches. From your window/door mark place the 1.5 inch end of the framing square on that line so that it is on the side of the line that is not in the window, draw a line on the opposite side of the framing square. To make this simpler let’s say that you started on the left side of the window/ door mark, you would be moving the framing square from that mark 1.5 inches to the left to draw your second line. You now have two lines that are exactly 1.5 inches apart and are parallel to each other. Move the framing square over again to your left 1.5 inches, line up the right side on the previous line and draw another line. You will now have three parallel lines exactly 1.5 inches apart on the left side of the window.

In the space between the two parallel lines next to the window draw a J, in the second space between the parallel lines draw an X. The j stands for jack and the X represents your stud. Some people call the Jack stud a slip stud.

You must mark a J and an X on both sides of the window/door openings. Every window and door gets this; mark sure the mark is on both plates and that they line up.

When laying out window and door locations remember to always measure from the same end of the plates, this will help make sure that no mistakes are made.

Now that you have your window and door locations you need to do your stud layout. Remember to start at one end and layout the studs at 16 inches on their centres. As you are laying out the studs you will mark the studs on their centres even through where the window opening will be, this is important later for your sheeting. The only place that you do not place a layout mark is where your doors will be placed. Leave that space unmarked.

Now that you have your studs marked out place your plates on the floor, place them on their edges parallel to each other with enough space so that the studs can be placed between them.
Before you start placing the studs between the plates you need to first cut and assemble your window and door edges.

For every J that you have on your plates you are going to have to cut a stud down to make the jack. Cut your jack to the height of your door; remember that there is a bottom plate so you will have to deduct the 1.5 inches off the overall height. Once you have the jacks cut for each side of your doors you then place them at each j and only nail the stud to the bottom plate.

For the windows you need to cut studs down to make your jacks, the jack height will be the height of your window plus the distance that the window will sit off the floor. Remember to deduct the 1.5 inches for the bottom plate. Place those jacks on each side of the window.

Now that the jacks are all in place you can go ahead and nail all your studs in their positions. When you come to the side of the windows and doors there will be that X that you place right beside the J. Place a stud there, nail it to the plates and then nail the Jack to the stud. Make sure that edges of the studs and the jacks line up, remember the jack is going to be shorter and that the jack starts at the bottom plate but should never reach the top plate.

When placing and nailing the studs do not place any studs in the window openings even though you marked studs there, those marks are for something else.

Take a 2x6 and cut it the width of your window opening plus 3 inches. Then nail this piece of wood on top of the jacks, if you measured properly it should run from one stud to the opposite stud across the opening for the window covering the top of the jacks. You nail this piece to the top of the jacks.

Now that you have the studs installed you need to install the headers for the windows and doors. The headers are pieces of wood installed above the windows and doors so that the weight of the roof or the floor above does not crush the opening.

To find out what size of header you will require for each window/door opening you will have to look at the house plans again, look for the header schedule, it will tell you the size and bearing that is required for the openings. To keep things simple let’s say that all the openings require 2 pieces of 2x8 above them and the bearing is only 1.5 inches per side.

Since you have the sizes of windows and door openings you framed then all you have to do is add the 1.5 inches of bearing per side. That equals out to 3 total inches longer then the width of the openings you just framed. Cut 2 pieces of 2x8 material to the proper length and then nail them together so that they make one piece of wood that is 3 inches thick. Make sure that the pieces of wood line up on all sides before you nail them together. You have just constructed your first header.

The header is to be placed at the top of the window/door opening right on top of the horizontal piece of 2x6 you already installed.  The header will sit on top of the 2x6 and will transfer its load onto the jack posts and if you cut it properly then it will fit perfectly between the studs that the jacks are nailed too. Because the header is only on 3 inches deep and your wall is 5.5 inches deep you need to nail the header in place so that it is flush with the face of the wall, that means it cannot be left on the deck and nailed. If you don’t nail it flush with the face of the wall there will be an un-insulated space in the wall that will allow cold to penetrate the home.

Once you have installed all the headers you need to finish off the framing around them. You marked the 16 inch stud centres on the upper and bottom plates, now you need to cut pieces to fit between the upper plate and the header on these marks. If you do it properly then when the sheeting is installed the ends will always end on the middle of a stud.

At the bottom of the windows you need to add the framing, measure down from the top of the framing of the window opening and make a mark where the bottom of the window will begin. Below that mark install a 2x6 horizontally from one jack to the other. This will be the actual piece of wood that your window will sit on.
Once that piece is nailed then you add in filler pieces at the 16 centre marks all the way across between this piece and the bottom plate, this is to catch your sheeting.

You have now finished the framing of the wall and can install your sheeting overtop of it. Remember to square the wall before installing it. Once you have the sheeting installed and nailed you need to cut out the windows and doors before installing the house wrap on top of the sheeting. Cut the sheeting out so that it is flush with the window/door frame. Depending on how many doors or windows are in your framed wall you sometimes will want to leave the sheeting covering a door. That is because the door creates a hinge point in the framed wall. Leaving the sheeting covering the door opening gives more support for the wall will insuring the wall will stay straight when the wind blows. You can always cut out the sheeting later once the roof is installed and the intersecting walls are framed.

Install your house wrap the same way you would if there were no walls or doors in the wall. Stretch the house wrap right over the holes, stapling it all around the window opening.

Once you have stood the wall up and have it properly supported then you can cut the house wrap out of the windows and doors. When you cut it out leave enough so that you can pull the house wrap in and around the window opening, this will help hold the house wrap from being ripped off by the wind.

Now you have framed an exterior wall with windows and doors.

Rob Abbott
Operations Manager
Village Builders Inc.