Scarfing the Ridge Beam

The ridge beam runs from the front of the house to the back of the house and is one continuous piece of wood that supports the entire roof structure. Naturally, this timber needs to be very strong!

I chose to use a 2x12 of Douglas Fir for this beam as it will be more than strong enough to carry out the task at hand. The problem is our tiny house is 18 feet long and the longest cut I can easily get is only 16 feet long. This is where this beam gets complicated.

In order to reach the full 18 feet, I decided to scarf two pieces of wood together and then reinforce the joint with butt blocks on either side.

The scarf was calculated and drawn out on the timbers. I highlighted cracks and checks in the wood to make sure that these defects were removed in the cut.  The cut was made with a circular saw a bit proud of the line. I then brought the faying surface right down to the line with a jack plane, chisel, and a rasp. All this work payed off because they fit very well on their first test fit!

Dry test fit shows how tight the seam is between the two boards

Dry test fit shows how tight the seam is between the two boards

I made a 4 foot scarf with nibbed ends, creating a very secure and sturdy junction between the two boards. A little bit of fine tuning got the boards very close together, producing a very tight seam that will be very strong once glued.

I separated the boards and set plastic wrap under them to prevent them from gluing themselves to the wood beneath them.

After applying a liberal amount of glue to the faying surfaces, I presented the edges of the scarf to make sure everything is lined up properly.

I then set the five clamps to hold everything together very tightly and squeeze out the excess glue.

For extra insurance I set 4 long screws to into the boards at an angle to help pull them together and offer structural support as well.

The clamps were all tightened down fully with the four 4-3/4" long screws holding the scarf nice and tight for the next few days while the glue sets. After the glue fully cures, the excess will be removed with a block plane as I prepare the sides of the boards for the butt blocks which will really tie it together!