My Pre-Line Checklist: Dry Frames ≤18% MC

I use this pre-line checklist on every Auckland job so frames are dry, evidence is solid, and inspections run smooth.

Pre-line checklist confirms ≤18% framing moisture content, stable indoor relative humidity (35–55%), and documented evidence via dated meter photos and logs. Steps include airflow through bays, right-sized dehumidifiers, power safety, and daily rechecks—so linings go on dry and council sign-off is straightforward.

Pre-line Fast Facts (Auckland)

Source: aucklandcouncil.govt.nz

🎯 My Pre-Line Goals (What I’m Proving Before Lining)

My pass marks at a glance

My first goal is simple: prove the frame is dry and stable. I sample bottom plates, studs, and tricky external walls until I’m confident the slowest members hit the target. I also keep indoor RH steady, watch temperature, and check that air actually moves through each bay, not just the middle of the room.

Where I sample and why

I learned the hard way that one “good” reading can be a trap. Now I take multiple readings in repeatable spots, label them clearly, and return to the exact places each day. Bottom plates love to hold moisture. Corners too. I always test those first, then move to representative studs per room.

“Sampling density should match risk profile,” notes Alex Hart, CPEng (Chartered Professional Engineer).

📏 How I Measure Moisture (My Meters & Method)

My pin-meter setup

I use a calibrated pin meter with clean pins, firm contact, and the right depth for framing. Low batteries lie, so I swap them early. I record the wood species if known and avoid metal fixings that can skew results. If a number looks odd, I test nearby members to see if it’s a local quirk.

My sampling routine

Each room gets a repeatable route: bottom plate left, mid-stud, top plate or nog; then the opposite wall. I tag locations on a plan or photo so tomorrow’s readings match today’s spots. This routine lets me spot trends instead of chasing random numbers. Consistency beats guesswork every single time.

My logging habit (with photos)

Every reading gets a timestamp, location code, MC%, plus a quick RH/temperature snapshot. I take two photos: one close-up of the meter and one wide shot for context. That way, no one has to ask, “Where was this?” Later, I sort by room and date so the story is obvious at a glance.

“Consistency is a stronger validator than a single ‘perfect’ reading,” says Dr. Priya Raman, C.Build E MCABE.

💨 How I Move Air (My Fans & Bay-by-Bay Flow)

My airflow path through bays

Fans aren’t decoration; they’re the delivery system for dry air. I angle flow along studs and plates, not at the ceiling. I use a ribbon test or just feel with my hand to confirm air reaches the corners. If a bay is stagnant, I nudge the fan, retest, and keep adjusting until it moves.

My “no dead corners” check

Corners, stair voids, and behind braces can turn into moisture pockets. I set a small fan to push through these choke points, then let the main fan pull the stream along the run. When in doubt, I lower the fan speed and change angle. Smooth, directional flow dries faster than brute-force blast.

“Flow direction beats flow volume in tight cavities,” argues Gina Morales, PE (Licensed Mechanical Engineer).

💧 How I Dry Fast (My Dehumidifier Sizing & Setup)

My dehu size picks

I start with a 90 L/day unit for a typical level, then scale up if the volume is big or the starting MC is high. I watch RH drop over the first few hours. If it barely moves, I add another unit or boost airflow. Right-size beats oversize when power supply is tight.

My drain and seal routine

Drains matter. I route condensate safely, keep hoses off walk paths, and cover trip points. Then I “seal to win”: doors and windows mostly closed so the dehu isn’t drying the street. If smells or dust build up, I pause, purge briefly with fresh air, and reseal before RH rebounds.

My “stall and purge” rule

When RH plateaus, I don’t panic—I troubleshoot. I check for cold surfaces, wet sources, and leaky envelopes. A short purge can reset the curve, but only if I reseal and restore flow. I’ve wasted days in the past by leaving windows ajar; I don’t make that mistake twice.

“Treat humidity like a controllable variable,” says Prof. Liam O’Shea, MSBE (Building Science Educator).

📸 My Daily Evidence Pack (Photos, Logs, Handovers)

My photo proof

I always capture the meter’s display and the wider frame so the location is unmistakable. I note the member (e.g., “BR2 bottom plate near corner brace”) in the filename. By the last day, the photo roll reads like a timeline: high to low, room by room, member by member.

My log template

My log has columns for room, location code, MC%, RH, temperature, notes, and operator initials. If I change gear or move fans, I write it down. Inspectors don’t need a novel; they need a clear trail. When everything is ≤18% MC and steady, my log tells that story simply.

My handover bundle

I hand over three things: the MC table, a short RH/temperature chart, and the photo set. That bundle shows method and result without waffle. It also protects everyone later, because it proves the frame was dry before lining. Fewer disputes, faster sign-offs, cleaner jobs for the next trade.

“Documentation is risk control, not admin,” notes Hannah Lowe, PMI-ACP (Project Management Institute).

🛠️ When Numbers Stall (My Troubleshooting)

My cold-spot checks

If readings stick, I check cold corners, steel interfaces, and shaded external walls. I’ve found a missed flashing leak more than once by chasing a stubborn number. I move air into the problem zone, warm the area if needed, and re-measure the same member later to confirm improvement.

My “add airflow” moves

Sometimes the dehu is fine; the air path isn’t. I add a small booster fan, re-angle the main unit, and declutter the bay. I also check for power trips or blocked intakes. A five-minute reposition can shave a day off drying if it clears a hidden dead zone.

“Bottlenecks, not averages, drive project time,” argues Marcus Bell, CSM® (Scrum Alliance).

🧠 What Industry Experts Say (How I Align My Practice)

How experts frame moisture targets

Most guidance lines up around ≤18% MC for internal framing, with emphasis on representative sampling and repeatable locations. Some prefer denser sampling near wet rooms. I’ve adopted that, because kitchens and bathrooms misbehave. If an inspector is conservative, I simply add a few more readings to remove doubt.

Where experts disagree—and my choice

Ventilation debates never end. Some push constant fresh-air purge, others want sealed, controlled drying. My rule: sealed to win, purge when RH stalls, reseal immediately. It balances speed with reality on live sites. It also keeps dust and noise down, which everyone appreciates—especially when trades overlap.

“Control beats brute force in occupied builds,” says Naomi Chen, WELL AP, LEED AP.

🧱 My Case Study: How I Got a Frame from Wet to Ready

I had a small detached dwelling come in after heavy rain. Worst member started at 24% MC on a bottom plate near an external corner. I set one 90 L/day dehu and two fans, aimed flow along bays, and sealed doors. By day three RH was trending down, so I held course and kept logging.

“Timelines compress when you fix the slowest element first,” notes Evan Doyle, PMP® (Project Management Professional).

❓ My FAQs (Straight Answers, Short Reads)

What moisture content do I need before lining? I aim for ≤18% MC across representative members and confirm with dated photos.
How many readings are enough? Enough to represent each room and risk area, repeated daily in the same spots.
Windows open or closed? Mostly closed so the dehu wins; purge briefly if RH stalls, then reseal.
How long does it take? From two days to a week, depending on starting MC, volume, and airflow.
Which meter is best? Calibrated pin meters for framing, plus good technique and repeatable locations.

“Clarity reduces rework,” says Sarah Patel, AQP (IAPP Associate Privacy Professional) — a reminder that simple rules help anywhere data is logged.

✅ My Takeaways & Next Steps

Dry timber, steady RH, and clear evidence make pre-line painless. I measure the same spots daily, move air through bays, right-size the dehu, and document everything. If numbers stall, I fix the bottleneck, not the whole site. Want a quick eyes-on check? I’m happy to run through the list and size the gear.

“Process discipline frees creativity,” says Owen Clarke, CEng MICE (Chartered Civil Engineer).