After about five years and three cross-country moves, the arm support on our three-seat Karlstad sofa gave out and needed repair. The rest of the couch was fine (despite our cat's inevitable scratch marks), and we didn't want to trash a decent couch we got for a killer deal without an attempt to fix it. We didn't want to make the 2 hour trek to the nearest IKEA to attempt to buy a new arm, and we definitely didn't want to invest in a new couch.

I spent several days searching online for some ideas on how to repair the arm and came up with nothing. Apparently, this is a very common problem with this type of couch, but I couldn't find a single tutorial or ideas for repair.

How the Arm Bolts to the Couch Body

If you have one of these couches, you probably put it together. It's really basic construction, and though most of the frame for the body of the couch is plywood, the arms are mostly particleboard and pressed wood, including the area of the arms that bolt to the body of the couch.

The arm bolts to the body of the couch with four stud bolts that fit into tee nuts, covered in a plastic plate attached with staples.

Extent of the Damage

When the arm broke, the arm fell toward the ground near the front foot of the couch. We flipped over the couch and saw that essentially, two of the stud bolts broke through the particle board frame: the one closest to the foot, completely through, while the bolt in the center of the frame merely cracked.

Because of the extent of the damage, there was no way to simply restore the bolts in their fittings. We were going to have build something into the frame.

The easiest thing to do to repair the arm was to fit a brace on the inside of the arm on top of the existing frame and replacing the bolts. This way, I didn't have to try to cut anything out of the frame, but still insured a secure repair

The Gameplan

Take the the couch apart
Create a template for a brace
Create the brace
Secure the brace to the frame
Put the couch back together!

Step 1: Materials & Tools

All the materials I needed for this repair cost under $15. I did already have the power tools and could have probably got by without buying more screws or glue, but it's was a much better deal that $500+ on a new, decent couch!

We reused some of the hardware from the original parts that came with the couch. The upper bolt near the top of the couch was fine, so we only replaced three of the four bolts in the arm at the bottom of the frame. We also reused the washers that came with the couch.

MATERIALS

(3) 5/8" carriage bolts
(3) hex nuts to fit bolts -- can't quite remember the size; we just fit them at the hardware store.
(3) washers to fit the bolts -- reused the washers from the couch
(6) to (8) #6 wood screws -- we used 8
wood glue -- we used Gorilla because it's the best
4 x 1 pine board, cut to 3ft at the hardware store. Depending on your store, you can have them cut the length for you. They had a scrap at the store, so we were able to just buy the 3ft we needed instead of the full length.
poster board or cardboard for the template
pencil, marker
beer for pre, during, and post construction

TOOLS

wrench or socket set
needle-nosed pliers
electric drill
1/16" drill bit for wood screws
3/4" drill bit for the carriage bolts
circular saw -- you could use a hack saw for this, but it was much easier and quicker to use the circular saw
circular sander -- doing this by hand is also fine
#180 sandpaper or whatever you have laying around
tape measure
clamps
allen wrench to take off the legs. This should have came with your couch or find the size that fits the bolts in couch legs.
Box cutter or knife

Step 2: Prep the Couch

Take off the cushions and tip the couch forward. Add cat.
Remove the legs. We have the optional, metal legs which required an allen wrench.
Use a wrench or socket set to remove all four nuts securing the body of the couch to the arm. This nut is metric, btw.
Remove the fabric cover of the arm.
On the inside of the arm, remove the stud bolts, plastic plates, and tee bolts from the frame with pliers. Remove any of the staples inside the frame that may have popped out.

A Note about Workspaces

You could totally do all of this work in your living room, but I would suggest, if you can, at least do the sawing and drilling in the garage, outside or on an old sheet or something.

Step 3: Make the Template

About the Template

It took a little bit of time to make a template, but it was well worth the extra time. First, I used a tape measure to measure each little section inside the arm to create a brace that would fit on the inside of the arm frame. I sketched out the template first on a sheet of paper (See the image above for measurements).

Then I used a piece of poster board and a ruler to create full-size template. Creating this full-sized template let me make sure that my board would fit inside the frame. Creating this template also made me realize that the brace actually needed to be in two pieces, so I could actually get the brace into the frame.

How to Create Your Own Template

Use the measurements in the image above to create a full-sized template out of cardboard or poster board.
- The sketch above is to create a brace for the right-hand arm when you're sitting on the couch
- I'm assuming you can just mirror the sketch to create a brace for the left-hand side, but I'm not sure.
- These measurements are specifically from my couch, and I'm making no guarantees it will be exactly the same for you or that my measurements are totally, 100% accurate.
- Always, always measure three to a million times, cut once and fit the template a few dozen times to make sure!!!
Lay your template next to the frame and cut the template into two pieces.
- Where this is divided isn't super important. I just made sure that my left-side piece overlapped the center bolt.
- There was about 3/4" to 1" between the two brace pieces.
Cut out your template and place it on the inside of your frame to make sure it fits. Adjust if needed.
Make sure your brace pieces fit snuggly, but not super tight inside the frame.
Make sure there is enough brace around the center bolt. I think mine ended up having about an inch to the right of the center bolt, which worked out great.

Step 4: Create the Brace

Using the template you just made and tested a few times inside the frame, center your template on your 4x1 board and trace the cuts with a pencil.
You can tape your template down on your board to make it doesn't move around on your board.
Take your template off your board and examine your lines. Do they look correct?
Double-check your cut lines with your template again.
After you make sure your cut lines mirror your template, carefully use the saw to cut your board.
Sand the edges slightly

Step 5: Fit and Secure the Brace

(I unfortunately got caught up in the drilling and gluing part of the project that I forgot to take more photos!)

Dry fit your boards to the inside of your frame. Make sure they fit snuggly, but not tight.
Make small adjustments to your cuts if needed.
Dry fit your boards again.
Once you insure your boards fit, take them out of the frame.
Use a box cutter or knife to trim some of the white liner from the outside of the frame where your holes will go, near the Velcro.
- Trim away the liner where the bolts are attached to the frame as well as were you anticipate your screws to go.
Liberally apply wood glue to board according to the directions on your glue.
Place the brace into the frame and clamp.

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You're probably supposed to wait until the glue completely dries to move on, but we didn't, and it turned out totally fine. This is probably a good time to go get a beer.

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With your clamps applied, use the 1/6" bit to drill pilot holes for your wood screws.
- We used about 3 to 4 screws for each piece of the brace.
- Space the holes out evenly across each brace piece.
- Make sure not to drill through your Velcro.
Secure the brace to the frame with the wood screws. Don't wrench them down super tight, or you may split your board.
Make sure your brace is flush to the frame.
Clean up any glue that may have squeezed out from under the board.
Change your bit to the 3/4" drill bit. Drilling through the holes already in your frame, drill pilot holes for the bolts into the brace.
Dry fit your bolts into the holes. Adjust if needed.

Step 6: Attach Your Repaired Arm

Once your glue is dry, take your arm back in the house and replace the fabric cover.
Line up your arm frame to the body frame.
Replace the bolt near the top of the couch inside the frame. This was the one we did not need to repair.

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Note about the Bolts

With the original couch hardware, the nuts and washers were attached on the inside of the body frame. Essentially, the bolt was coming from the arm into the body and secured.

With our repair, the bolt will be attached in the opposite direction: the bolt will be coming from the body into the arm, attached the nut and washer to the bolt inside the arm frame.

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One at a time, slide the bolt into each pilot hole from the body toward the frame.
Add a washer and then a nut. Begin tightening, but don't tighten all the way down.
Attach the other two bolts.
Tighten each bolt evenly until the arm frame is flush with the body frame.
The heads of the carriage bolts should sit down into the body frame. Give them a little tap with a rubber mallet if they need some encouragement.
Replace the legs on your frame
Remove cat, flip your couch upright, open a beer, sit on your repaired beauty and relish in your accomplishment!