The Gate Project, part 3
Posted by joeabbott on February 19, 2011
This is the third in a series of posts about a project I jumped into last summer.
The Gate Project, Part 1 discusses the problem I was trying to solve. It was short but had a little picture of the “old gate” … yeah, that piece of plywood that was leaning against our fence gave us something to clip the plastic fencing onto. It wasn’t super cool but it did the trick.
The Gate Project, Part 2 mainly discusses the posts. This was the key as our soil and my skills conspired to keep this from being simple. Or that’s my contention.
The Gate Project, Part 3 deals with the arbor or overhead beams, their design, and how I ended up with the look.
The Gate Project, Part 4 covers the construction and the installation of the parts discussed before.
The Gate Project, Part 5, wraps up the series with the building and installation of the gate.
In this installment, I’ll go over the rest of the design for the pergola part of the gate. I’ll do another segment on the installation, and a final piece on the gate. Now, you might think I’d talk about the gate before the installation piece but, I completed the project in the order that I’m writing.
The July 2010 issue of Wood magazine carried plans for a “Basic Built Pergola” that strongly influenced my design and thinking. Or “warped it”, in my wife’s view. To be fair, it was all my doing and Suzy was never as critical as I make things out … but once I made the leap from “simple gate” to “gate with supporting structure”, I was open to influence from many sources.
The Wood magazine just gave me some ideas and helped flesh things out a bit.
For starters, it showed me the idea of simple overhead cross beams. This is a pretty basic design element but I was new to this space so I’d never considered it before. Seeing it in print helped a lot. To help the discussion, I’ll refer to “path-wise” and “across-path” beams. As their names suggest, the “path-wise” beams are those that parallel the path, of which we had two. The “across-path” beams numbered four and were those that spanned the path.
I wanted both to have structural qualities so that they might help to lock in the space between the posts. For the path-wise pair, I used joinery that would ensure they locked things in; for the across path sets, it was sheer numbers that helped in this regard.
The Path-wise Overheard Beams
I like construction, am an engineer, and been “into” (not practicing, but doing a lot of reading about) woodworking for a while now, and those help out, but I have no experience in practical construction. Although I soon shall not be able to say this as I’m doing a lot of stuff!
I recall no mentoring for this sort of thing as a youth, never took “shop” classes in school, and while I worked a part-time summer job in construction, I was inside slinging paint, sanding woodwork, and learning to hate manual jobs. How things look so very different now.
Anyhow, I saw the July Wood magazine and liked the “look” of things. I liked the strong line, I liked that it looked like something I could build, and I liked the meaty structuralness of it all.
But Suzy made it clear that she very much didn’t want a “tunnel”: the strong overhead crisscross of beams and closed-in look didn’t appeal to her.
As I “thinned out” the overhead beams and looked at how they were connected, I fell out of love with this design, too. Lots of butt joints and lag bolts. I wanted to avoid fasteners as much as possible. I’m not completely sure why, but I do know that, when talking to woodworkers, they almost always eschew screws when possible, and they’re rarely part of the visual design. And, yes, I realize this is not a “woodworking project” … it’s landscaping construction … but I aspire to woodworking levels!
So, if I didn’t like screws and I didn’t want butt joints, my options were limited. And then it hit me: mortise through the beam!
The SketchUp design looked great and while it was a monster mortise, it should be doable: cutting through cedar beams would be like running a hot knife through butter! And then, for a touch of elan or joie de vivre, I planned to cut a big slicing chamfer off the bottom! Huzzah!
So I’d solved the path-wise beam problem by designing slots into the posts and planning on sliding a 2×6 path-wise beams through. This would be a super-stiff joint that would keep the posts aligned along the path. And, while I didn’t have the entire details cemented, I thought to use wooden dowels as pins to hold everything in place.
The Across-Path Overheard Beams
For both a design element and to give just a touch more headroom, I wanted to cut an arc in the bottom of the beams. Then, to complete the look, I’d chamfer the ends to match the path-wise beams.
The hard part here is that the across-path beams needed to be about 8’ long … and I wanted four of them. Oh, and, for the arc to look good, I’d want 8” deep boards so I could cut out 5-6” and leave a solid bit of wood behind.
Well, I looked at five lumber yards and only found one that had an 8” wide cedar board in the 8’ lengths that were reasonably clear. These boards had two strikes against them: they were too thin, at 1” nominal (but really only 5/8” rather than the usual 3/4”), and they were expensive! I forget what exactly they cost but it was a pretty penny. And for four of them! Ouch!
Anyhow, I didn’t feel I had a lot of options so I got the thinner boards and decided to live with it. Rather than planing them smooth, I sufficed to sand down only the roughest parts and life with the minor imperfections. From a distance, who would know?
Oh, one more thing. Because the boards were thinner, I ended up modifying the arc I struck in the bottom to be shallower and avoid removing as much material. While it’s still a fair curve, it’s not as aesthetic as I’d wanted. It’s just that I was worried that if I cut out too much wood, the board would end up warping a lot.
And like on the path-wise beams, as a near afterthought, I decided to use wooden dowels to hold the beams in place. Unlike the path-wise beams, I wasn’t able to design in through dowels as I was sandwiching the posts and wouldn’t be able to trust going through the three layers. Now, I realize this is a cop-out … technically, I should have been able to do this. But, with assembling in place with hand tools and on a ladder in the back yard … no thank you!
And that was it
And so the pergola design was done. Sure I needed to execute on the plan, there was the whole issue of the gate not being anywhere near to completed (I’m not even sure I’d really started it!), but I was ready to start letting chips fly! This is the fun part, actually: being done worrying about all the design issues, feeling confident enough in the plans that we can begin to execute, and not having to sweat the actual problems that arise in any construction job.
I was ready for the next part: the installation.