HOW TO MAKE A WOODEN ZIG-ZAG TRELLIS : BEWOODED

Do you remember my DIY pallet wood herringbone table top? During that build, I had to run a huge number of pallet planks through my table saw to neaten the plank edges. Doing this created a ton of thin strips of pallet wood. Initially, I thought they were pointless but I just couldn’t bring myself to throw them out. It seemed like such a waste! Boy, am I glad I kept them because I finally thought of a project to use them up. All hail this awesome zig-zag trellis!

THE PLAN

I have made a couple of trellises before and thought the process was really fun. They were patterned like diamonds and I currently have them attached to my garden shed. This trellis here was to go on the front of the house and I wanted something unique looking.

This is when I came up with this zig-zag look. After all, it looks quite unusual but is still super simple to build. I did struggle a bit with figuring out how to connect the individual zigs and zags in a way that looks tidy. I decided to simply run a few lengths of thin wood from the top to the bottom of the trellis frame and then build the zig-zag pattern by attaching small pieces of pallet wood to these base planks. This sounds super confusing but this whole project has plenty of pictures so don’t worry – all will become clear.

In terms of the actual design. This trellis will be holding my climbing passionflower and that bad boy grows very quickly. I needed quite a big trellis, so I decided to make it 180cm x 90cm. When I started the build, I didn’t have any specific sizing in mind for thicknesses or widths of different pieces. Honestly, I just wanted to use up my scrap pieces of pallet wood in a productive way. I ended up with mostly uniform pieces but some thickness differences caused a few fillable areas at the end of the project. In the materials list, I will estimate the thickness, widths and lengths of my pieces but I’ll also pop in links to new wood that would be suitable for this build if you aren’t planning on using any old scrap.

The build itself is a sort of layer by layer build. Here is a design I made illustrating how the trellis will fit together step by step:

MATERIALS & TOOLS REQUIRED

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Materials

As I said, I used pallet wood cut offs for my trellis but you don’t have to. If you are considering using pallet wood, make sure to check out this post on the benefits and downsides of using it before you run out to find some.

Strip wood for the zig-zag (blue part in the design)

You need enough to cover the face of your trellis in the zig-zag pattern. I used various sizes but each piece was roughly 1-2cm wide, 80-100cm long and around 3-5mm thick. If you’re buying wood, this here is a good choice. For a trellis my size, you should be ok with 7 of these but if you want to play it safe, get 8.

Strip wood for the zig-zag backing (orange part in the design)

You need 7 strips long enough to run from the top to the bottom of your trellis. I used my pallet scraps which were not long enough. I had to use 14 strips and join them in the middle. The size of my strips was roughly 1.5cm wide, 80-100cm long and around 1cm thick. If you’re buying your materials, these here are a good choice.

Trellis frame inner section (pink part in the design)

The frame inner section is a strip of wood that is attached between the two frame faces and runs along the outer edge – it’s a bit like a sandwich filling that’s slid to only one side. I used more scrap pieces that measured roughly 2cm wide, 80-100cm long and 1cm thick. The size of this piece does depend on how thick your strip wood for the zig-zags and the zig-zag backing is. The way these inner frame pieces are placed, they should be wider than the thickness of both of those combined. For example, my zig-zag backing is 1cm thick and my zig-zags are 5mm thick at most. That meant my inner frame pieces needed to be at least 1.5cm wide. You will need around 5 of these and you’ll need to join a few pieces together but as these are hidden from view, this is fine.

Wider pieces of wood for the trellis frame (green and purple parts in the design)

The pallet wood strips I had for these measured around 6cm wide, 80-100cm long and 0.7-0.9cm thick. Because I had such short lengths, I needed 13 of these and had to make most frame parts by joining two wood pieces. If you’re buying your wood, these here should do well. At 1.8cm thick, these are a little thicker than the frame pieces I used. You will need 6 of these to build the frame without mid joins. Note that the wood suggested is a little less wide than what I used. This is because I couldn’t find anything in the store that was wider but just as thin. I think going less wide will look just as nice though and shouldn’t impact the actual build process. If you do spot something wider then go ahead and use that instead if you prefer.

x4 metal corners for fixing the frame together
15mm panel pins
20mm panel pins
Screws
Wood filler
Wood paint – I used Cuprinol Garden Shades in Country Cream
Wood glue
Concrete screws – you can also use normal screws with wall plugs

Tools

Pen/ pencil
Ruler
Tape measure
Sandpaper
Hammer
Handsaw
Mitre block
Drill with bits for drilling the wall and a bit to fit the screws

STEP 1: BUILDING THE BACK OF THE TRELLIS FRAME

A: JOINING THE LEFT AND RIGHT FRAME PIECES

If you’re buying new wood and you get the 2.4m lengths suggested above, you don’t need to do this step. For me, because I was using pallet wood, my longest planks were only 1m long. This was perfect for the top and bottom frame pieces. However, as I wanted my trellis to be 180cm high, I needed to join my left and right frame pieces to lengthen them.

To do this, I cut 45 degree angles on two of my planks, laying them in the mitre sideways. This is what you’re trying to achieve:

I then joined the two pieces together and glued them using wood glue. I popped my trusty exercise bar weights down on top and let the glue dry. I repeated this again for the other side. In total, this used 4 of my planks.

B: ATTACHING INNER FRAME PIECES

Next, I decided to attach the inner frame pieces. All I did to start with was glue planks that were long enough across one edge of each back frame piece: across the two newly glued side frame pieces and across 2 1m lengths that would become my top and bottom pieces. I needed to join the inner frame parts for my left and right frame pieces, in the same way I joined the outer frame pieces. Please note that the inner frame pieces need to be attached sideways, i.e. you are joining the width of the frame piece to the thickness of the inner frame piece. This doesn’t matter if you are using the wood suggested above where the thickness and width are the same, but if they differ, the width needs to be longer and be the unattached face (see my pics below).

During the next step, I realised that wood glue was nowhere near strong enough to hold these together so I went back and used some pins to attach them. I would recommend that you skip the glue and just attach the pieces with pins right away.

C: CUTTING THE CORNERS

After the glue has dried and the back layer of the frame was now attached to the inner frame pieces with pins, it was time to cut the corners. To prepare my top and bottom frame pieces, I got 2 of my 1m framing pieces (now with inner framing pieces attached). I cut a 45 degree angle using my handsaw and a mitre block on one edge of each plank, making sure that the longer edge would be the one with the inner frame piece attached to it. I then measured 90cm from the cut corner and marked this spot. I cut another 45 degree angle here but the opposite way: you want your plank to be a sort of trapezoid shape. I did the same thing with two of my longer, glued planks that will become the left and right frame pieces but measured 180cm instead of 90cm. After all the corners were cut, laying the planks in position takes us to stage 2 of the design images with green and pink parts 🙂

D: JOINING THE BACK OF THE FRAME TOGETHER

It was now time to secure the frame together. At first, I glued the corners together and used a couple of pins to hold them. However, a few steps down the line, I tried to lift the frame to put it away for the day and it literally fell apart – glue and pins were not strong enough to hold it. This is when I decided to use metal corner brackets to hold the pieces together. When I went to the store to get them, I found out that these brackets are called ‘L shaped strap ties’. I’ve no idea why.

As my framing planks were so thin I couldn’t screw the corner brackets directly to them. My screws were just too long. Instead, I used a few bits of scrap wood to ‘pad’ underneath the brackets. The screws were just long enough to reach the frame but not go all the way through. This held the frame together very well. As I said, I didn’t actually add these brackets until further on but it would have saved me a headache if I did. If you’re following along, get those brackets screwed on at this stage.

STEP 2: ATTACHING THE ZIG-ZAG BACKING STRIPS

The next step was easy. I had to simply run 5 out of the 7 zig-zag backing strips from the top to the bottom of my trellis. Of course, as I was using pallet wood, my strips were not long enough. This meant I had to use 10 lengths and join them somewhere around the middle. I cut the join using the usual sideways 45 degree cut. To attach the strips to the frame I used a couple of pins per strip. At this stage, I left my joins in the centre unattached to each other. This is because I had such poor luck with glue holding stuff together at this point that I thought I may as well just join them when I get to them.

I spaced these 5 strips evenly in the centre of the frame, i.e. I had 6 equal-sized holes inside the trellis frame.

There are still 2 of these strips left to attach to the left and right frame inner edges (4 pieces of wood in my case). You can attach these at this point if you want but I left mine until later on. If you are attaching them now, see the orange strips in the design images for a guide.

STEP 3: CREATING A TEMPLATE ZIG-ZAG PIECE

After all these boring steps I was super excited to start actually building out the pattern! The first thing I did is grab one of my strips for the zig-zag pattern and placed it in a way that I want it to run from one of my zig-zag backers to the next. I marked it where the edges needed to be cut to make sure that the piece is reaching exactly half of the width of the backer and so that the next piece can sit flush next to this one.

I cut it to size and did the same thing again but placed a piece the opposite way, next to the first piece. Once they slot together, they form a triangular sort of shape. I checked that they were identically sized, which they should be if your spacing of zig-zag backing strips was on point. I used just one of these strips as a template to cut a ton of these little zig-zag pieces of wood ready for assembly.

STEP 4: ASSEMBLING THE ZIG-ZAGS

The actual assembly was really fun. To start with I just ran the design between the 5 backing pieces I attached. Honestly, this is because I was too excited to see how the zig-zag looked so didn’t want to faff around attaching the 2 remaining backing pieces just yet. To build the design, I just aligned the cut pieces with each other and used 4 pins per piece – 2 on each end. It’s a little difficult to explain in words how to build the pattern so check out the pictures below for guidance. Note that the pins you’re using here need to be tiny and you need to be soft handed when hammering them in. It’s really easy to split thin wood like this if you’re heavy handed. Also, make sure to slide a piece of scrap wood underneath the place you’re joining – the frame lifts the zig-zag off the floor so you need to make sure something is supporting it underneath for you to hammer effectively.

Once I put the first row in, I realised that I needed an easy way to space the rows evenly. I used one of my pre-cut zig-zag pieces and marked it where I was going to start the next row, see the image below. I then used this piece to mark the place where each individual zig-zag piece should start relative to the one in the row above it.

When I reached the place where my joins were in the zig-zag backing strips, I made sure that when I was attaching the zig-zag pieces, one end was attached to a top backer and one to a bottom backer. This way the zig-zag strips were holding the support pieces in the right place relative to each other. I also popped a pin into the joins for a bit of extra support although I don’t think they added much strength.

I got to the bottom quite quickly and had to move on to attaching the final 2 zig-zag supports on the left and right frame edges. The process is the same as with the other 5 but they sit inside of the frame and should be invisible once the front frame layer is attached. This is where, if you’re using the 44mm frame wood suggested, you will notice that there isn’t enough frame width left to run the backer all the way to the top and bottom of the trellis as I have done. This is ok – all you need to do is run the backer as long as you can. If you find that you need to attach a zig-zag piece to the part without a backer, find a piece of scrap wood that is small enough to not stick out past the frame. Pin this to the frame next to the corner and attach the zig-zag to it.

After my backers were attached, I could finally start filling in the left and right gaps. This also didn’t take very long and soon I had a fully zig-zagged trellis!

STEP 5: ATTACHING THE FRONT OF THE TRELLIS FRAME

The last part of the build was to attach the front of the frame for which I needed to cut the frame pieces down. The easiest way to do this was to go edge by edge. I would lay a plank across an edge and then mark where it needed cutting. For left, right and bottom frame pieces, these had to be joined in the middle. I used the usual sideways 45 degree cut to get a clean-ish join. As each piece was cut to size, I used pins to attach it. Now I had a complete zig-zag trellis!

STEP 6: FINISHING THE TRELLIS

As I built my trellis from pallet wood cut-offs from previous projects, I had plenty of nooks and crannies due to pieces of differing thicknesses. If you’re using new wood or cutting pallets to size for this project specifically, thickness issues shouldn’t be a problem for you. Hopefully, you won’t have to slab as much filler on as I did to hide these scraggly bits!

Once my filler dried, I sanded it down to blend everything together as much as possible. I also slabbed on a couple of coats of Cuprinol Garden Shades in Country Cream. Unfortunately, you could still see some of the joins in the frame but it doesn’t look too bad after it was painted. I’m not too worried about them – after all the point of a trellis is to be hidden by a climbing plant anyway!

STEP 7: ATTACHING THE TRELLIS TO AN EXTERNAL HOUSE WALL

Now came the final job of attaching it to the house. I hate drilling into walls – it’s so messy! But it did need doing so I used a small stool to lift the trellis to its final height. I then drilled one hole in the trellis and the house and used a concrete screw to attach it. I then used the stool again and used a level to level the trellis up before drilling and screwing in a second concrete screw. I then removed the stool and put a couple more screws into the bottom of the trellis.

THE RESULT

I love the final look – it’s really unusual! It is a shame about the obvious joins in a couple of places but I really wanted to use up my scrap wood instead of cutting something new for this project. Besides, I don’t think the joins will be this noticeable when my passion fruit climber gets going. Those things grow like weeds!

THE PLAN