Hemlock for homebuilding

The virtues and pitfalls of hemlock as a house-framing material. June 20, 2000

I am thinking of building a home in western NY. I have heard that Amish-milled hemlock (rough cut) can be purchased cheaply. Can this lumber be used for building a home? I have heard it is not as strong as spruce/pine/fir (SPF), yet I know of many barns built with hemlock.

Can it be used for outbuildings, but not a home?

Has anyone out there used this type of lumber for building a house?

Forum Responses
Hemlock is good for framing lumber as long as it isn't too knotty.

I've sawn a lot of hemlock for house and shed framing. One job I cut was for a whole house, from floor joists to rafters (all 2 x 10 material). I cut 2 x 6s and 2 x 4s for studs. The customer used hemlock for the floor and roof sheathing, and for siding.

We use as much hemlock as we can for our own building projects.

If you compare clear hemlock to clear SPF, hemlock is stronger. You need to avoid knots which would greatly reduce the strength (this is covered in the grading rules), as well as shake and other defects.

This is true for all species, though hemlock may have more shake than other species.
Gene Wengert, forum moderator

The worst thing with hemlock is shake. It makes some pieces unusable and that is probably why we don't see it in the lumber yards.

Sometimes the board will split lengthwise in two pieces right off the saw. The diameter of the knots is always a factor in strength, but could be adjusted to the use (just like spruce).

Overall, it is a good wood that is strong and heavy, and retain nails very well.

A word of caution about using ungraded lumber: Check your local region for applicable building codes and regulations for using lumber.

If your location falls under a building code - western NY falls under BOCA (Building Officials & Code Administrators International, Inc.) jurisdiction - building officials will not allow anything other than grade-stamped lumber to be used for framing.

New York State passed a law several years ago that allows native lumber to be used in construction. It requires a grade stamp if the producing mill states on the invoice that the lumber is No. 2 Common or Better.

The catch is that not many small mills are certified to grade the lumber or can afford to have a certified grader come to the mill to grade a small quantity. Also, it's ultimately up to your local building inspector as to whether he's going to allow the use of this lumber, even though state law says it can be used.

Here in Wyoming County, NY, anyway, farmers don't need to get a building permit or have the building inspected as long as it is for agricultural use. This is why you see a lot of small mills in the area cutting 2x's.

I have built many homes and barns from hemlock. You have to pick through and get a good sawyer, one who mills to a consistent thickness (they're hard to find sometimes ). I also live in western NY, and deal a lot with the Amish.

I agree -- ungraded hemlock, especially because of shake concerns, will not meet building code requirements in most cases, so it cannot be legally used for housing. However, properly selected hemlock is great.

Your first stop should be to the building inspector's office. The Uniform Building Code indicates "...or equivalent," so maybe you can get this phrase working for you. Often with just one home the inspectors will be easier to live with than if you are building several.

Hemlock is the eastern variety of Douglas fir, and rates very high as a framing lumber. As to shake, it is usually an obvious defect.

Regarding certification, an engineer can certify the structural integrity of hemlock. I have cut hundreds of thousands of feet for houses and barns with high satisfaction from my customers.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor R:
Hemlock is not an eastern variety of Douglas fir. Hemlock (Tsuga heterophylla) is its own species, which differs greatly in wood properties from Doug fir (Pseudotsuga mensezii). A more likely reason you will not find hemlock readily available at your wood dealer is due to difficulty in drying it and its propensity to warp while drying, which makes it less appealing for merchantability. Less yield per kiln load and more warped, unusable pieces.