Measuring and marking a deck. You bend down, pencil a line, stand up. Bend down, pencil a line, stand up. Forty times in a morning. By lunch, standing up straight takes a second longer than it should. By knock-off, the drive home is the worst part of the day — the seat locks the back into one position, and getting out of the ute is a careful operation.
Or it’s running sheets of ply on a framing job. Carrying them two at a time because it’s quicker, twisting to fit them into the frame, bending to nail the bottom plate. Or installing floating floors — three hours crouched over, clicking boards together, neck down, back bent.
Carpentry loads the lower back constantly, from multiple directions, for most of the working day. It’s not one heavy lift that does it. It’s the accumulation.
What a day on the tools actually does to your spine
The lumbar spine — the lower five vertebrae — is designed to carry load and transfer force between the upper body and the legs. It handles flexion (bending forward), extension (arching back), rotation, and combinations of all three.
Carpentry asks for all of these, repeatedly, often under load. The structures that absorb that stress are the discs between the vertebrae, the facet joints at the back of the spine, and the muscles and ligaments that hold the whole thing together. Any of these can become the source of pain — and in carpenters, they often share the load.
The three things that usually go wrong
Lumbar disc irritation
The discs are the shock absorbers between the vertebrae. They handle compressive load well, but they’re vulnerable to repeated flexion — bending forward — especially under load. Lifting a heavy sheet with a bent spine puts significant pressure on the disc. Do this repeatedly, and the disc can bulge or the outer fibres can develop small tears that become inflamed.
Disc pain typically sits centrally in the lower back, sometimes with a band across both sides. It’s usually worse in the morning — stiff when you first get up — and can be worse after sitting or driving. If the bulge is pressing on a nerve root, you’ll get pain, tingling, or numbness running down the leg: the classic sciatica pattern.
Worth saying clearly: disc bulges show up on scans all the time in people with no pain. A scan finding alone doesn’t tell you much — what matters is whether the disc is contributing to your current symptoms, and that’s a clinical assessment, not an imaging one.
Facet joint loading
At the back of each spinal level, there are two small joints — the facet joints — that guide movement and share some of the load. They’re fine with normal motion, but they don’t like sustained extension or combined extension and rotation — which is exactly what happens when you’re nailing overhead, arching back to check a line, or working in a tight wall cavity.
Facet pain tends to be more one-sided than disc pain, often worse when you arch back or twist toward the painful side, and better when you’re moving and worse when you’re still. Framers and formworkers — who spend time overhead and in extension — tend to develop this more than finish carpenters.
Muscle overload and trigger points
The muscles running alongside the spine — the erector spinae and quadratus lumborum — hold the back in position while you’re bent forward or twisted. Sustained loading in non-neutral postures causes these muscles to accumulate tension, develop trigger points, and refer pain into the lower back and glutes.
This is the ache you feel at the end of a flooring day or after measuring out a whole deck. The joint structures are often fine; it’s the muscles that are carrying the load and haven’t had a chance to reset. Trigger point pain feels like a deep, dull ache — sometimes a specific tender spot you can press on, sometimes a broader band across the lower back.
Why the weekend doesn’t fix it
Two days off isn’t enough, once the back has reached the point of consistent pain. You rest, the acute irritation settles slightly, Monday arrives, and within two hours on the job it’s back to where it was. Each week, the baseline gets slightly worse and the recovery slightly less complete.
The other reason is compensation. When the lower back is sore, the body protects it by stiffening the surrounding areas — the hips, the thoracic spine, the glutes. Those compensations reduce range of movement and transfer load to other structures. A chippy with a sore lower back often develops hip and thoracic stiffness that makes the lower back work even harder to compensate. More on why back pain keeps recurring →
What hands-on treatment does
For carpenter’s back, effective treatment usually involves:
- Manual therapy on the lumbar spine and hips— restoring movement through the stiff segments that are loading the painful ones. A level that’s painful is often painful because the levels above and below it aren’t moving enough. Getting the whole stack moving again reduces the load concentration.
- Thoracic mobilisation — the upper and mid back stiffens significantly in trades workers who spend most of the day bent forward. Stiff thoracic spine forces the lumbar spine to do more rotation and flexion than it should, which accelerates disc and facet wear.
- Soft tissue and trigger point work— the QL, erector spinae, glutes, and hip flexors all need direct attention. These don’t release with stretching alone once they’re properly loaded up.
- Dry needling — effective for releasing deep paraspinal trigger points that are hard to reach with manual pressure alone. Particularly useful for the QL, which sits deep beside the spine and refers strongly into the lower back and hip. More on dry needling →
- Targeted strengthening — not a generic core program. Specifically the glutes and deep abdominals, progressed to match what the job asks. The goal is reducing how much the back has to compensate for weak hips on a lifting day.
Practical changes on the job
- Adjust the sawhorse height.Most carpenters set their saw horses at a height that’s convenient for the material, not for their back. If you’re bending forward to measure or cut, the horses are too low. A few minutes with the adjusters saves hours of back loading over a week.
- Kneel instead of bend for low work. Flooring, decking, skirting — anything below knee height is better done on one knee than bent at the waist. Your lumbar discs take a fraction of the load. Trade-off is knee wear, so alternate sides and use a pad.
- Hip hinge for picking up. Bending at the hips — keeping the back relatively neutral and pushing the hips back — loads the glutes and hamstrings instead of the spine. Worth making a habit of for anything you pick up off the ground, not just heavy sheets.
- Use a panel carrier for sheet material. Carrying ply sheets flat or balanced on the shoulder loads the spine asymmetrically. A panel carrier keeps the sheet vertical and both hands working evenly. Slower to use, but the cumulative load difference over a day of running sheets is significant.
- Change positions regularly during sustained tasks. Flooring and decking keep you in one position for long periods. Setting a rough 20-minute timer to stand, arch back slightly, and walk for 30 seconds breaks the sustained disc load cycle. It feels unnecessary until you notice the difference at knock-off.
When to get it seen
Worth booking in if:
- Pain has been there more than three to four weeks without clearly improving
- Pain, tingling, or numbness is running into the leg — this is nerve involvement and needs assessment sooner rather than later
- Morning stiffness lasting more than 30 minutes
- You’re changing how you work to avoid the pain — altered gait, avoiding bending, not lifting your share
- It’s waking you up, or you can’t find a comfortable position to sleep
Leg pain is the flag to move quickly on. Nerve symptoms from a disc bulge respond well to early treatment; left unaddressed, the nerve irritation becomes entrenched and the recovery timeline gets longer. More on tradie pain and when it matters →
The honest takeaway
Lower back pain is the most common reason tradies retire early from the tools. It’s also one of the most treatable things I see in the clinic — when it’s caught before it’s been going for three years and the compensations are fully ingrained.
The back that aches on Friday but is “right enough” by Monday is telling you something. It’s not fixed — it’s recovered just enough to go again. Get it properly assessed and addressed, and you’ll get more out of it for longer.
I work weekends. You don’t have to take a day off the job to come in.