Wood: The Pergola (Part 2)

Thought you folks might want an update on how the work's going on a recent post featuring a timberframed Pergola that Chad is building for a neighbour.

Things worth mentioning:
#1 Mortises can totally be cut without the use of a chain mortiser! Why is this good news? Because chain mortisers are pretty pricey. Here is the one Chad is after. It's in Chad's opinion that Mafell are some of the finest made woodworking tools currently on the market. Check out their philosophy if your interested and have a chance. Overall, it takes a bit longer to cut mortises without a chain mortiser (about 5x), so if your in a hurry....maybe splurge for the tools.

What you need to cut mortises without a chain mortiser:
* 1 1/2 " ultra smooth wood owl auger bit 
* 18 volt Metabo drill (The big selling feature on this drill for Chad.....the 3 year warranty on the batteries....unheard of)
* 1 1/2" and 2" Barr Framing Chisel
* A wooden mallet 

#2 Know your sawmill! The wood we ordered looked beautiful, but there were a few characteristics that made it tougher to work with. 

* Watch for timbers that are out of square. Out of square timbers can make layout difficult and makes it next to impossible to get connections to fit perfectly.

* Wavy timbers. This effect happens when the band (blade) on the sawmill is dull. Wavy edges also make layout a challenge since you have no totally flat/straight edge to lay your framing square against (Note: framing squares are used for laying out a timberframe).

* Watch for inconsistent sizing of timber. The timbers in this frame varied in dimension by over 1/2" making layout a challenge and adding the extra step of measuring each timber before cutting the joint that will receive that timber in a connection.

Really if you can, check out the sawmill before you order. If possible try to take a look at the timbers milled by your sawmill and look for any of the above potential issues.

#3 Build under cover! Although it's seems like such a romantic and back to the earth idea to do all your cuts and layouts in the great outdoors, you really don't want to be working in the rain.....this pergola was actually laid out and cut inside a garage, except for the trellis ridge pieces shown here. These cuts were done quite quickly with a circular saw, jigsaw, and a chisel. Chad is using a timberframer's chisel to square up the sides and basin of this notch. These were also stained outside before the pergola was raised, and were tarped until needed.

The client for this timberframe has rather tall son-in-laws so he was worried about the clearance of the pergola just under the eavestrough of his back deck. So, Chad agreed to cut a curve in the center cross-beam for this frame to account for those standing just under 7 feet. Oh yeah, they're the biggest son-in-laws I've ever seen. Due to a shortage of necessary tools (i.e. tools usually used for this cut), Chad used his faithful Stihl chainsaw (Larry) to cut this curve. It might look from this angle that he is totally off of his line, but this is actually pretty good practice for getting the cut accurate. Afterwards he went back and brushed down the rest of the wood to this line with the chainsaw to get a really smooth finish on the curve.

Oh yeah, 'shaving' the top of this curve really looks more like bouncing the edge of the chainsaw off the surface and moving it back and forth while trying to control the extent of the bouncing. Kind of like shaving a garden hedge.....just imagine the curve is a hedge. This takes control in order to not cut through the curve.

Let us know how your projects are going, and if you have any questions or comments related to this post or timberframing give us a shout at chadwickhillier@gmail.com.