Evolution of a (Not So) Rustic Bridge

It all began when my husband pruned a whole lot of branches from some fruit trees. I had already been plotting and planning to make a rustic bridge for quite a while before that, but did not know quite where to start!

The Inspiration

Ever since I got hooked on the idea of making a rustic bridge, I had been bookmarking sites and saving pictures in a google drive folder, of anything rustic - furniture, gates and yes bridges. I had also started saving sites and pictures of regular, not necessarily rustic bridges which were mostly cedar.

Where do I begin?

Being Ms. Frugal, I combed the internet to see if I could find instructions for free on how to make a rustic bridge. I found a couple on how to make a standard bridge, but nothing on the rustic front - not for free at any rate! So I knew I would have to rack my brains, experiment, fail, get frustrated and do it all again...

The first thing that I had to decide on, was how big - or small - I wanted my bridge to be. After measuring the area that would serve as its final resting place, I determined that it would have to be between 4’ and 6’ long, with a width of around 2’. Another thing to keep in mind was the standard dimensions that lumber comes in - especially since I already had some knocking around on the property.

There were some old planter boxes made out of 2x6x9 cedar that had seen better days and we were planning on getting rid of. The corners had been mitered so one edge was 9’ and the other was around 8’. I figured I could get the two main stringers from one piece, which meant their longest dimension was doomed to be no more than 4‘ 6” (at the base). When shaped, they ended up being 4’ 3 ¼” at the base and with the curve that ended about midway down the width of the 2x6, they were slightly over 4’ at the top.

Plotting the Slatting

Now I only needed to worry about covering approximately 4’ with slats. The slats would be made out of 2 x 3 lumber that had been in the back yard for eons (leftover from a pergola construction by the previous owner) and which we really needed to get rid of… so I had to use it - and quick - or I would lose it! They happened to be right around 81 inches long, which meant I could get three 27” long slats from each piece.

These pieces of 2 x 3 lumber were unusual in that they were 2 ¾” wide, not the normal 2 ½”. This worked to my advantage because by including a ¼ inch space between each slat, I could use 3” as my base for calculating the number of pieces needed to cover the 4’ of deck.

3” times 15 = 45”. But I needed to cover 48”. No biggie, I could either just leave 1 ½” (half of 3) uncovered at each end or gently ease it into the spaces between the slats.

Posted

I knew right from the onset, that I wanted this bridge to have posts and rails. The original plan was for most - if not all - of the bridge to be made out of branches. But I could not find enough matching pieces to satisfy my perfectionism! As a compromise, I decided that in addition to the deck, the posts would also have to be made out of cedar. And thus began the slow de-rustication of the bridge plans… By now only the main rails and the little radiating rails would be truly rustic. But figuring out how to attach even those rails to the posts and keep them from wobbling was making my head hurt!

A Little Sketchy

With the main part of the bridge being pretty standard, I realized that I would have to focus my energies on the posts and rails. So before I even started with the bridge construction (and I had to do this before the branches got dragged out to the curb with all the other yard waste), I arranged and rearranged branches on the driveway (first through third pictures) in a bid to create the two symmetrical sides. These look (and must be constructed) no different from rustic gates… Then I got out a pen and paper and started sketching various bridge designs combining branches and twigs with patterned posts, till I came up with one that I somewhat liked. Based on this sketch, I drew templates for the cedar posts and cut them out of large pieces of cardboard (from boxes). The rough bridge sketch and cardboard template are in picture # 4. As can be seen in picture # 5, before actually cutting the two main posts out of another 2x6, I arranged the template with the real twig rails on the driveway to ensure that I still liked it. Pictures # 6 & 7 show a little before and after where the post on the extreme right has been sanded after being cut.

Branched Out

I found one good candidate in a gently curved branch with just the right length for the top/main rail but simply could not find another that was long enough to match. What I ended up doing was using the best part of the best match that I had and splicing a piece from another branch to make up the missing length. I cut and sanded them so that their ends fit flush. Then I drilled a ⅜“ wide, ½” deep hole into each end and joined them with glue and a 1” dowel.

Since the top/main rail was a naturally curved branch and I wanted the center post to be about 32” high from off the ground, I had to lay the side posts down in position beside the center post, to determine exactly how long (tall) they would have to be. I could not merely rely on calculations here because when working with natural materials, one soon learns the meaning of customization. One also just as quickly realizes the value of a dry fit as much as measuring and labeling EVERYTHING!!

Tools of the T(i)rade

1) Measuring Tape

2) Jigsaw

3) Electric Drill with accessories (drill bits, driver bits, hole saw, spade bit, drum sander)

4) Wood screws

A Cleansing Workout

As mentioned, the cedar had been sitting in the backyard for a couple of years and I could see that it would need some serious elbow grease to get them clean! So I decided to carry out the cleaning step after cutting the pieces to size. That way they could fit into my kitchen sink where I was able to scrub each piece with dishwashing detergent - the kind that contains bleach. And yes, I did wear a mask (because I am allergic to bleach) and goggles because I didn’t want any of this stuff splashing into my eyes! The first picture shows one of the original (yucky) slats beside a cleaned one.

Slinging the Stringers

To keep the stringers connected (and keep them from toppling over) while trying to affix the slats as well as to provide some support at the highest point on the bridge, I knew there would have to be some sort of stretcher spanning the stringers. If this piece was to carry any weight, (I know, I know, punning is the lowest form of wit) the mass being supporting would have to distributed. So just screwing in a vertical piece that straddled the stringers was not going to cut it. Why? Because all the load would be borne on a single screw going into end grain at each extremity of the stretcher. Aha - joist hangers (second picture) would solve both problems - the load distribution as well as the end grain issue!

The first thing I had to do was find the midpoint on each stringer. That was simple enough. Then I placed the joist hangers over the top end of each stringer and eyeballed them into position so that they were as centered as possible. You can see this in the third picture. I traced the outline of each joist hanger on the top surface of each stringer (where they would sit) and used a hacksaw (a rasp might have made more sense here) to remove just enough material for the hangers to sit flush with the surface of the stringer. This is visible in the fourth picture. Then I replaced the hangers, drilled appropriately sized pilot holes and screwed them in. The fifth picture shows a screw with its matching drill bit. Joist hangers were designed to be used with nails, but I prefer using screws wherever I can...

Oops (#1)!
With the joist hangers in place, I cut one of the extra pieces to sit in the joist hangers. But it sat lower than I expected it to (sixth picture). What happened?? It needed to be a 2x4 - not a 2x3!

Ordinarily one would assemble the entire main bridge before adding posts - if desired. Which means that you would attach all the slats, then come back and remove the ones where posts would be attached. You would then have to trim the overhang from off those slats and reattach them, as visible in the first picture. Since I was not using bolts and wanted the attachment of the posts to be invisible, I had to screw them to the stringers from the inside.

Backwards Assembly

So the very first things that actually got permanently attached to the stringers were the mid posts - not the slats! I also wanted the screws that went horizontally into the joist hangers to serve double duty - going all the way through the stringer and into the post… The second picture shows a 3" screw spanning the combined width of a mid-post and stringer. Directly above the screw is an extra long drill bit on which the hole depth has been marked with masking tape.

Why use an extra long drill bit? Because standard drill bits increase in length based on their thickness, so if you wanted to drill an almost 3" hole with a #8 or a #12 drill bit, then you would have to drill in two stages. I don't like this method because there is always the possibility that while drilling the continuation (second stage), the drill could go off at a slight angle to the original drilled hole, making precision near impossible.

Why the tape? Because I did not want to accidentally drill a hole all the way to the front of the stringer.

I then added two more screws, pre-drilling in all cases. Once that was done, I set the two pairs of stringer-mid post combinations in position beside each other and laid the central 2x4 to rest in the cradles of the joists (third picture).

Hang it!

I could now get on with the task of attaching the slats. When attaching the slats, I used a flat plastic garment hanger as a spacer between them. This is visible in the fourth picture.The first of the slats to be attached was the middle one, which had to be trimmed so that it sat in between the two already attached mid posts. Next were the two slats that flanked these mid posts. The corners on one edge of these had to be trimmed off and shaped very carefully because the posts were/are curved (fifth picture) and it took fore-e-e-e-e-e-e-e-ver!

I decided I definitely did not want to be doing this again for the side posts, so I positioned them squarely in front of the stringers, such that they would only need to be trimmed off their overhang. And for additional support, I placed two stretchers directly under their trimmed slats, just like I did with the central one. But this time I used a different kind of joist hanger, one that was less heavy-duty which I figured would be easier to install… Now I could also make use of the 2x3 lumber - including the piece that was originally cut for the central hanger (the one that sat too low) - which meant I now only had to cut one more piece for the other side.

It Ain't Over Till It's Over!

I thought the smaller, simpler joists would be easier to install but due to their shape they blocked access to the stringer and would have prevented the stretcher from sitting flush in it. I ended up having to bend one of the tabs backward (one that I was not using anyway), such that it was in the same plane as the seat that the stretcher would lay on. With access to the stringer, I could now drill the required holes and screw down the joists. I drilled one of the holes all the way through the stringer and once I had fine-tuned its position, I continued that drilled hole it into the side post. This could only be done after the preceding slats were screwed into place. In reality, I affixed all the slats then came back and removed the one where the post would go. Remember this is one of the three that I had trimmed to make space for the posts to sit flat against the stringer. The second post went a lot faster because this time instead of tracing the position of the joist onto the stringer, I held the stretcher in place and traced around both sides of its edge that abutted the stringer.

Common Sense is the Most Uncommon
I was working on the driveway since I did not have an elevated area large enough for the bridge. That made it really difficult to mark the holes for the screws that would go into the two side joists. Drilling horizontally into the stringers was even worse. What I could have done, and later did, was just raise the bridge a little because at this point it was stable and rigid enough to do so. I propped it up on two layers of pavers that were leftover from when we had our driveway paved. This made life soooo much easier!

How to attach the main rail and the radiating rails to the central post?
It suddenly occurred to me that I could use pipe clamps for the main rails, and I did - after shaping the top of each central post to match the rounded profile of its rail. Again, this had to be customized for each rail. These pipe clamps were bent so the tabs would no longer be at 90 degrees to the circular portion. I used the cheapo aluminum - or are they galvanized steel? (Painting them black might have made them look like some pricey hardware!)

Figuring out how to attach the radiating rails was a major dilemma -.to say the least! I thought about tenoning the ends and fitting them into corresponding holes in the posts. With this plan in mind, I spent some good money on two styles of tenon cutters, only to realize that they could not cut tenons small enough for this project. They are scary looking beasts which I still plan to use on a future project. And if I survive to tell the tale, I’ll write another ible… JK, I’ll be careful - safety first, which means I might have to rope my stronger half in! After a lot of mental back and forth, I decided to double up on the side posts and drill holes through the seam. So the side posts are now composed of two posts, an outer full-length post and an inner shorter one that starts from and rests on the upper surface of the slat as seen in the first picture.The seam and hole are visible in the second picture. I used a spade bit for the rough hole, then widened (if I needed to) with a rasp and finally neatened it up with a mini sanding drum. The third picture shows the spade bit and sanding drum. Then I threaded the rails through the holes. As for how to attach them to the central post, I decided to just screw them - I mean the rail ends - to the post.

Oops # 2

I had cut and shaped all the inner (short) posts first and was working on the outer ones kinda piecemeal so I could do a final dry fit against the inner one before actually cutting it to size. Why do the shorter ones first? They needed a bevel at both the top and bottom ends, so it would have been a lot more difficult trying to match them to the longer posts. I hope this makes sense!

I had completed one and fixed it to the stringer with two screws (remember one of these went through the mini joist hanger). I had removed the short slat to enable working under the bridge. With that done, I went to work on the opposing post. Now I knew they all had to be around 31” but I wanted to double check and so measured it against the short post while holding the latter in place. The mark seemed quite a bit lower than where I was expecting it to have been, but I dismissed it telling myself that the piece of lumber was probably longer than I had thought it was.

Like a fool, I went ahead and cut it first and checked it later, against the one that was already installed. This is what happens when you start getting impatient! The measurement kept coming up more than an inch shorter and I could not figure out why. Suddenly I realized that I had measured this long post against the short post while it was sitting directly on top of the stringer - because I had removed that trimmed slat (as you can see in the picture), which like all the other 2x lumber, is an inch and a half thick! Thereby hung the tail… So as punishment to suit the crime, I had to go and cut myself a new long post, scrub it clean and let it dry! Fortunately, I had not yet carved and sanded in the scallops along the long edge - now that would have really hurt!!

Believe me, there really was! The entire project, the planning as well as the building, followed a highly integrated approach. So even though it seemed like I was going about the project in a random haphazard manner, I followed a very specific set of steps and did so systematically. This was not a cut and dried, three-part (or pronged in Spice-Speak ;) project like one might expect, where you first build the deck, then you add the posts and last of all, you add the rails. The rails did go on last but that was the only traditional aspect of the build. Rather, I was continuously thinking ten steps ahead to how I would approach a certain feature and that in large measure, dictated a lot of the decisions I made regarding the overall design and the sequence of steps.

For instance, I had to attach the two main posts to the stringer first (before attaching the slats), because I did not want huge bolts to be visible on the outside. The decision to double up on the side posts was not just because I thought a single 2x3 would look (and probably be) flimsy; it was my solution to the problem of how to attach those multiple radiating rails to the side posts. I figured by having two layers of the post, I could sandwich the rails in between.

At this point, I had not yet finalized exactly how it would come together or how it would look. I did not know whether I’d carve out some material from the posts so that the rails would have something to ‘sit’ on without all sliding down to the bottom, or whether I’d bring the two posts together all the way and drill a hole for each rail at the seam, like I ended up doing. Of course, I could have very well used 4x4s, but that occurred to me only after the fact. Besides, like I mentioned in the very beginning, one of my main goals was to use up the material that we had laying around.

The next largish bridge I make will definitely have 4x4s as posts - no matter what I use for the deck and rails. And with my current experience - or lack thereof - it’s probably going to be quite a while before I even attempt to make that totally rustic bridge (or anything rustic for that matter)!!!