DIY House Addition: Step 4 – Framing

Foundations are fun, I agree, and not just because 1.) you get to dig a bigass hole in the ground, and 2.) my family owns a foundation company. Actually, I retract that statement… those are the reasons why foundations are fun and if you want to know more about them check out DIY House Addition: Step 3 – Foundations.

Because frankly, we have more interesting things to discuss here. Like lumber! Framing nailers! And the point in time where the big hole in the ground starts to resemble and actual house! The mental exclamation points at that stage in the building process cannot be overstated.



Okay. Enough of the excessive punctuation. Let’s talk about framing.

Framing: Not just for pictures.

Framing, in fact, does not exist for itself– and for laymen like us it’s best to remember that. Framing exists to hold up your siding. To give you something to nail your roof shingles to. To support your insulation. To keep up your drywall.

You have to think of it that way so that you understand why you don’t use 8′ studs (because with the top and bottom of a wall frame you’d have an 8’4″ wall height, which means a 4″ strip of drywall somewhere on your wall… and let me just say, been there, done that, tried to off myself by sticking my head in a five gallon bucket of joint compound before all was said and done). Or why you use at least three 2×4’s in every corner (you’ve got to have something to nail the drywall to from every angle.)

So here’s the real deal… unlike foundations–for which I strongly suggest you use a professional– framing is something you could DIY if you understand the codes, and have enough people to lift up the walls. But I would practice on something other than your house the first time around. Trust me, you will learn some things.

I’ll tell you this about our own house addition– I wanted to frame the house and was adamantly against hiring it out. I mean I don’t own a framing nailer for no reason, people. But. But with only two of us, and two full time jobs, and not enough time to get it framed and weather-tight for winter, we spent the money to hire a crew for the bulk of the framing for our addition. (The cost of labor for this was about 8% of our overall budget.)

What you need to know.

Whether or not you’re actually wielding the nailer, there are things you should know about the frame of your house, and they begin with this:

Let’s dive in, shall we?

Framing starts from the foundation up because of, duh, gravity, the Laws of Physics, all of those other things my Own Personal Engineer keeps trying to beat into my head.

Anchor Bolts – See the bolts sticking up out of the foundation?
They keep your entire house from blowing away in a slight breeze. Don’t skip that step.

Technically they are part of the foundation. They should be at least 1/2″ in diameter, and spaced every 6′ and within 12″ of a corner or any door openings.*

Sill Plate- Generally 2×6 or 2×8 (pressure treated)- Lays flat on the foundation (with holes drilled for the anchor bolts to run through) and is attached with washers and nuts screwed into the anchor bolts.You may or may not have some sort of gasket under the sill plate– but you probably should.

Rim Joist – Runs around the perimeter of the sill plate. Your floor joists will be end nailed into the rim joist. We replaced a rotted one here.

Floor Joists – If you stand in an unfinished basement and look up, those pieces of wood running parallel to each other are the floor joists. They hold up your floor. Your floor joists rest on the sill plate and “dead end” into the rim joist at the end of the house. They also rest on your beams (which are usually directly under your load bearing walls).

Let’s break here for a brief diagram…

There… makes more sense that way, doesn’t it?

The diagram is a little misleading, and not just because I drew it out of scale in Powerpoint. More because some of these things will be offset to account for sheathing (5/8″ plywood that covers your house and floor). We’ll get to that in a minute though. Moving on…

Bottom Plate – The bottom of a “framed wall”. This is usually one 2×4 or 2×6. The wall studs are end nailed or toe nailed into the bottom plate.

Wall Studs – Again, 2×4 or 2×6 (2×6 walls are becoming more standard- especially for exterior walls) usually 16″ on center. These make up the “center” of a framed wall.

Top Plate – The top plate is made up of two pieces of wood and is the top of the framed wall.

Then we get into the exciting parts that make up the roof, like…

Roof Trusses- Roof trusses are a strange beast. You can buy them pre-fab (rafters, supports, and ceiling joists are all one piece) or build them on site. Here’s a traditional roof structure.

Sheathing – The whole house (and roof) should be sheathed in 5/8″ plywood or OSB. It comes in 4×8 sheets and they should be run horizontally in a “brickwork” pattern (staggered seams) for maximum stability.

And those are basically your pieces. Even if someone else is doing this for you, you should know what the pieces are and how they fit together.


First and foremost, your frame is just that – your frame. It determines the heights, widths, openings, and “squareness” of your house. (Is squareness a word? Probably not, but that’s why this is amateur-hour and not “ProfessionalBuilderDiva”. The opposite of crooked. How’s that?)  The important thing to note is that most of those things are regulated by building codes. Particularly (but not limited to):

  • Ceiling heights
  • Size of door openings
  • Width of hallways
  • Construction of stairs

Building codes also regulate, the types of materials you can use, how they have to be fastened to each other, where you can and absolutely cannot cut, notch, or drill holes in things, and almost anything else you can think of that would affect the structural integrity of your house.


You just know I rub my hands together and cackle a little when I say that. Here’s a suggested list:

  • Hammer (or Framing nailer & compressor)
  • Nails – a lot of them
  • Square(s)
  • Level(s)
  • Chalk line/ plumb bob
  • Tape measure
  • Saw (I prefer a miter saw and circular saw, but any combo of those, a table saw, and hand saw would probably work)

Step-by-step (kind of)

I don’t know how you could not have had enough of this already, but let’s go into even greater detail, since we’re here anyway.

Subfloor –

  1. 2×6 or 2×8 pressure treated sills go over the anchor bolts. If the exterior wall sheathing needs to be flush with the foundation, offset these 5/8″
  2. There should be a gasket under the sill plate, and you may also want to caulk around both sides of the plate
  3. Rim joist should be installed flush with the outside edge of the sill plate.
  4. Floor joists– 2×8 or 2×10– should be attached to rim joist, 16″ on-center. These can be end nailed (through the rim joist and into the end of the floor joist) or attached with floor joist hangers. (Joist hangers are attached to the rim joist first, then the floor joists are dropped into place and attached.)
  5. 5/8″ or 3/4″ plywood or OSB should be attached to the outside of the rim joist and on top of the floor joists to create the subfloor. Seams should be staggered.

At this point, it should look like this:


Basic Wall Framing-

  1. Walls are built and then fastened into place. (Not built in place.)
  2. Use the decking on your brand new sub-floor to lay out the walls. Set bottom and top plate. The top plate is doubled up, and at the corners one piece should extend over the other piece so you can lap the corners,  like this…
  3. After you set your top and bottom plate, measure for your studs. 16″ on center, but remember, you want to make this work for a 4×8″ piece of drywall on the inside- after you place your first stud, measure 15-1/4″ from the end of the first stud, which will be the “near edge” placement of your second stud. Then everything can go 16″ from that. (If you think about it, if you just went 16″ on center, you’d end up with a 3/4″ gap, since your drywall doesn’t start in the middle of the first stud, but on the edge of it.)
  4. Studs are sold in 92″ (actually 92-5/8″) heights to accommodate for a bottom plate, two top plates, and still give you the exact height you need for two 4′ rows of drywall, and room for ceiling drywall as well.

Corners- It takes as many studs to do one corner as it does to do 2.5 lineal feet of straight wall. There are a couple of ways to do them. Remember, you’re going to need to nail sheathing to the outside and drywall to the inside, so you need to have a nailing face available on the inside and outside of the corner.

Doorways & Windows – There are even more fun terms for doors and windows.

  • King Studs – Complete studs that run the full height of the wall outside of the window.
  • Header – Tw0 2×12’s spaced out with plywood create the top of the window or door opening.
  • Trimmer Stud- Runs from the bottom of the header to the bottom plate
  • Sill – bottom of the window opening (for windows, not doors)
  • Jack Studs – Run from the bottom of the sill to the bottom plate.

Sheathing – So here’s something interesting I learned living on the Ohio/Michigan border. In Ohio, most builders frame the walls, put them up, then attach the sheathing. In Michigan they frame the walls, attach the sheathing, then lift the whole thing into place. It’s up to you to decide which is better. Either way, these apply.

  1. Sheathing should start/end in the middle of a stud. (Except on corners)
  2. Seams should be staggered.
  3. General rule of thumb for nailing: every 6″ on the edges, every 12″ in the center. However there are specific regulations for this, particularly on the roof, and even more particularly in areas where roofs often blow off (read -hurricane zones) they may require every 3″ on the outside and 6″ on the center – so you have to check local regs.

1800 words about framing later.

Did you seriously just write 1800 words about framing a house after midnight? Yes. Yes I did.  We’re not all sawdust and donkeys around this place.

Now go forth and frame to your heart’s content…


If that just wasn’t enough building information for you, check out the rest of the DIY House Addition series.

*As always, I speak in Michigan regulations (which are some of the most stringent in the country) because that’s where I went to contractors class and where we’re building our house.

11 Responses

  1. Can I give an amen for suggesting that foundations belong to the pros? Despite being a very handy couple and having the help of my master carpenter father- we called in the pros for the foundation of our (still being built) four car garage. It was a long process to find someone and cost us a lot of money, but in the end it was completely worth it! That is the foundation that our entire garage, something we want to stick around for a long long time, is being built off of. So much more went into our foundation than just a quick layer of cement.

  2. Bolts are kind of important — a co-worker discovered his house wasn’t anchored to the foundation–after an EF3 tornado came through his neighborhood two years ago. Trapped his wife and kids in the basement when the house slid across the foundation and then collapsed on top of them. Luckily, everyone was ok — but you can bet his new house had bolts in the foundation –lots of them.

    1. I’ll tell you, when we replaced the sill plate we found the same thing for our house. Luckily we replaced or build around almost all of the walls.

      Tornadoes w/o anchor bolts = definitely bad news.

  3. What a great introduction to framing! It’s really interesting to hear about typical residential construction in other areas of the US. Most of it is basically the same in California.

    How do you nail the wall sheathing at the corners of the walls if you apply it before lifting the wall up? Do you just leave extra sheathing along the edge?

    You might be interested to know, here in California, A.B. are spaced at 48″ max. Haha, a little construction trivia.

  4. Wow, that is a great overview of wall framing. Take a peek at the attached website, it is a new product that I have invented to help speed up wall framing for the DIY’er and the pros alike. I would love to get your thoughts/feedback and can send a sample if you would like one.



  5. This is a fantastic and detailed post! Was wondering what are the best practices for attaching the new addition to an existing house-particularly when the addition is not the same width as the existing structure? I get I need to take the siding and sheathing off but then what? If it lines up with an existing stud, just nail the edge of the new wall to it? If it doesn’t, do I insert a new stud into the existing wall and then attach the edge of the new wall to it? I hope that made sense…

  6. I am wanting to extend a gable roof out over my patio. What I would be doing is tying into the end of an existing gable and going straight out approximately 18 ft. I will have a vaulted ceiling in the cover. I want to be sure that I tie the addition to the existing house properly. Can you tell me where to look to get such information?

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