Choosing the Lumber, Building the Walls and Applying Exterior Sheathing to Your Small House

It is important to be aware of proper wall framing basics because the walls of your small house will bear the load from the roof down to the foundation and act as the protector against the elements of changing weather for many years to come. Basic carpentry framing for the walls must be accomplished with future projects in mind such as drywall and kitchen cabinet installation. If the walls are not constructed properly it will make these future projects difficult to achieve.

The framing basics of your wall include the sill plate on the bottom, the wall studs (which are the vertical beams), and the top sill plate (which is the beam running across the top). It sounds simple in theory, but to get a wall plumb and square takes a lot of practice.

My favorite method for finding the square of a framed wall is to measure from corner to corner. If you envision a basic rectangle… the measurement from opposite corner to opposite corner should be exactly the same. The other common method is the 3-4-5 triangle to get a 90 degree corner.

Framing a wall, or anything else, in a house seems like a simple concept. If you stand outside a house under construction it looks like the builders simply nailed together a bunch of 2x4s in a kind of grid pattern to make a skeleton for the building. There’s a lot more to it and especially to do it right. But, to get it right it takes some precise measuring, measuring again and then cutting. The old adage of “measure twice, but only cut once” cannot be overstated!

Termites a Potential Problem?

For the majority of homes constructed in the U.S. (and many other countries), the framing will be done with dimensional lumber. Occasionally, metal framing will be used in place of wood. Metal framing may be a necessity in areas of high termite populations. Check with your local building supply store to see if metal framing members are special order items– most places they will be — which could add significantly to the cost of your house.

Using materials for a house that termites can’t eat would seem like a no-brainer. But, actually obtaining enough metal framing parts, or enough masonry materials, can be a real problem. Wood for building is so abundant and relatively cheap that the long term cost of battling termite damage is easy to overlook. Check with your future neighbors, if possible, to find out their problems with termites or carpenter ants. It’ll give you a picture of what you’re likely to have in a few years.

Picking Good Lumber

If you have the chance to pick out your lumber at the supply store then jump at the chance. Sure, it’s hard to tell the straightness of pieces that are buried in the middle of a pallet full of lumber. However, if you have fewer than 50 pieces of lumber to buy, then looking down the length of each piece for straightness is worth your time. Keep in mind there will be slight variations that include twisting and curving but the pieces you want to avoid are the ones with obvious and severely noticeable variations. They’re best in the firewood pile.

If you have to rent a pneumatic hammer to do your framing it is money well spent. If you have other building projects in mind in the next decade or so then buying one should be part of your budget and will serve you in a lot of ways in the years to come. If you’re feeling “luddite-ish” then by all means get yourself the best framing hammer you can buy.

Sheathing The Walls

Wall framing basics also includes the type of structural wall sheathing you will use to strengthen the walls, add substance to the insulation that you will be using, and provide a base for applying the house siding material.

Standard exterior structural sheathing is usually made of plywood, oriented strand board (OSB), exterior gypsum board, or waferboard. If you are considering another type, be sure it is rated as structural wall sheathing. Some builders put sheathing on a framed wall as it lays horizontal on the floor, while others apply it after the wall is tipped up into place. Everybody has their favorite method, largely based on who they learned it from in the first place. You framing subcontractor will probably have a preference one way or the other just because “they’ve always done it that way”.

Don’t Forget The House Wrap

Tyvek is the most common house wrap around here (the Midwest). It basically serves as a kind of wind jacket for the house, hinders air from leaking in directly through the walls (mostly), and is also waterproof.

Be sure to have more than one person on hand during wall construction and sheathing because it often requires one or two people to hold things in place while another performs the attaching by nailing everything down.

*reprinted with permission from Peter Hotton, 2009.