How To Measure & Cut Parts For Outside Walls

• How to calculate the dimensions of studs

• How to cut all studs to size accurately

• How to calculate the size and placement of rough openings for windows and doors

• How to cut rough opening parts

• how to cut top and bottom plates

• how to mark off top and bottom plates 16" on center

• How to mark off window and door location.

• How to fit sole plates (bottom plates) over sill plates

• how to fabricate corner studs (Intersection Box.)

Outside Wall Section

1. How to calculate the dimensions of wall studs.

   • First you will need to figure out how high you want your ceilings to be inside the home.

   • Once you have that measurement, add 1/2" for sheetrock, and 1 1/2" for strapping. This will give you an exterior wall height.

   • Now that you know how tall your exterior wall will be, its time to calculate the length of your studs.

   • To do this you must subtract the height of the sill plate, bottom plate, and both top plates, from your total wall height.

   • The result will equal the length of your studs.
     

     Outside Wall Section

     

2. How to accurately cut studs to size.

   • Your best bet is to cull all of the studs for your house at once. This will ensure even studs throughout and will reduce the wave effect on ceilings and roofs.

   • Square off all of your stud lumber on the Chop saw. This involves cutting off a thin piece of each stud to create a straight end.

   • Set up a jig on your chop saw table, measuring the exact length of your studs.

     • A jig is a setup that will enable you to cut many boards to the same measurement without measuring each one.

     • First make a box out of boards on either side of the chop saw. The box should align evenly with the chop saw surface.

     • Next measure a stud to length and cut it.

     • Lock the blade in the down position on your chop saw.

     • Place the cut stud snuggly against the blade surface.

     • Once the stud is lined up, take a block of wood and screw it down into the box behind the cut stud. The block must sit snuggly against the stud.

     • You now have a block to place each piece of lumber against. This will ensure the same measurement for all cuts.

   

3. How to calculate the size and placement of your window, and door, rough openings.

   • How to calculate the size of rough openings

     • Measure the height and width of the window or door, then add 2" to each.

     • If your window is 3' x 5', then your rough opening will be 3' 2" x 5' 2".

     • Rough openings are larger than the actual size of the window or door, to leave a little room for play during installation. Also new buildings have a tendency to settle and move over time.

   • How to calculate the placement of rough openings.

     • You must first figure out how high you want the top of your windows to be off the floor in your home.

     • This measurement will be the top measurement of your window rough openings.

     • Next, you must figure out where on the wall each window is to be placed.

     • Once you have found the placement of each window, mark off the height and width of each plus 2".

   • Doors are slightly different because the door assembly sits on the floor.

     • Measure the height of the door and add 2" to that measurement from the floor.

     • Do the same for the width of the door.

   

4. What are the rough opening parts?
   

   • Studs, Trimmer studs, Headers, Rough Sills, Cripple Studs.

5. How to measure the dimensions of rough opening parts.
   

   • Trimmer studs will run from the bottom plate to the header / the top of the rough opening.

   • Headers will rest on top of trimmers and against studs.

     • They will therefore be 3" wider than the rough opening dimensions.

     • The thickness of the header must be constructed to equal the exact width of your studs.

     • The height of the header will depend on the width of the rough opening. The wider the rough opening the wider the lumber. Check your local codes for dimensions.

   • Rough sills will rest against trimmers and will therefore measure the same as the width of the rough opening.

   • Cripple studs support the rough sill. Their measurement will be from the bottom plate to the bottom of the rough sill.

   • Cripple studs above headers will measure the difference between the header and top plate.

6. Cut all of the rough opening parts you have just measured, to size.

   

7. How to make a header.

   • Making the header is a little more complicated because it involves a variety of calculations. Headers are constructed of 2x6, 2x8, or 2x10, lumber. Your local building codes may require you to use specific size lumber depending on the width of each rough opening.

   • Once you have chosen the appropriate size lumber, cut 3 lengths for each rough opening (for 2' x 6' walls.) Remember that the header fits over the trimmers so it needs to be wider than the rough opening.

   • Next, you will need to cut out 2 pieces of 1/2" plywood to the exact dimensions of the boards you have just cut.

   • Combine the plywood and boards together to form the header. You can glue and nail them together, or just nail them together. This will form a very strong support for your roof.

   
   

8. Top and bottom plates

   • Measure the length of the first section of wall you wish to build

   • Cut both top plate and bottom plate, to that measurement.

   • Mark the location of each element of the wall section onto the top and bottom plates. This will depicts the exact location of each stud forming the wall.

   • Align both top and bottom plates side by side. Using a large square, draw a line marking the exact location of each piece to be assembled.

   • Marking both plates at once will ensure identical markings on both plates.

   • Studs must be placed 16" on center throughout the house. this will create a nailing surface for both interior and exterior sheathing.

   • Draw a line where the edge of the stud will be, and an "X" on the side of the line containing the stud.

   • The first stud marking must be 15 1/4" from the end and then 16" on center there after.

     

   • Rough opening markings must be drawn onto both plates as well.

   

9. How to assemble corner and intersection boxes.

   • These boxes create nailing surfaces for adjoining exterior walls and intersecting interior walls.

   • Use 2 pre-cut studs for the sides of the box, and smaller scrap pieces for the interior of the box.

   • Nail it together as shown in the diagram below.

{Next Step: Framing & Raising Outside Wall}