Pressure Treated Wood vs Redwood DIY Guide That Feels Like Shop Talk
Sunlight hits the back porch and the scent of fresh cut planks fills the air. You grip the saw handle and hear the blade whine as two neat piles wait beside the bench. One pile shines a faint green. The other glows deep red. Your nose catches a cedar like sweetness from the redwood yet your mind recalls the sturdy promise that rides with the green stock. That single choice stalls many builders in the store aisle.
I reached that same stall ten years ago when I made a slim bench for family dinners outside. Redwood slats felt warm under late day light and they charmed every guest. Rain mixed with sprinkler spray soaked the rear legs and soft pulp replaced hard grain within one season. I swapped those legs with pressure treated posts then slid the same seat back on top and the piece has shrugged off eight winters. My hands learned the lesson for you.
This guide hands that lesson in clear steps and plain talk. I weave in the key phrase pressure treated wood vs redwood so search tools notice while you read with ease.
Quick pick list
- Choose pressure treated stock for any part that touches soil or hides under finish
- Choose redwood for surfaces that eyes see or skin feels
- Mix both woods in most decks benches and planters to save cash and add years
Pressure treated wood in simple words
Softwood like pine slides into a sealed tank. A pump pulls air out then water mixed with copper salts floods in. Pressure climbs and drives the fluid deep into the cells. The tank drains and vacuums again then boards exit heavy and green. Sunlight slowly dries them.
Tags tell the protection level.
- Zero point one five pounds of preservative per cubic foot handles parts above ground
- Zero point four zero handles soil touch and splash zones
- Zero point six zero handles posts buried in wet ground
Fresh boards carry a green tint that can push stain toward brown. Plan your finish with that fact in mind.
Redwood beyond the color
Redwood grows on the cool Pacific coast where fog feeds slow rings. The dark heart holds oils that bugs dislike and those oils slow rot. The pale outer ring has little oil. Grade matters.
- Clear heart holds all heart wood and very few knots
- Heartwood common mixes heart wood with a few knots
- Construction common blends sapwood with many knots
Pick heart heavy boards for seats and rails. Dry kilns reduce water so joints stay tight when seasons swing.
Key numbers that guide picks
- Strength. Pressure treated pine carries heavy roof or deck loads
- Rot check. Pressure treated wins in wet soil while redwood wins above ground when grades hold heart
- Movement. Redwood shrinks less and swells less
- Finish. Redwood drinks oil and glows yet pressure treated needs more prep
- Cost. Pressure treated hurts the wallet less while redwood costs more when clear
Project match guide
Decks
- Pressure treated for footings posts beams and joists
- Redwood for deck boards rails and stair treads
- Tape joist tops to stop trapped water
- Leave neat gaps so boards breathe
Outdoor seats and tables
- Pressure treated only for hidden parts or legs on soil
- Redwood for arms backs seats and trim
- Round sharp edges so oil coats smooth
- Seal cut ends before screws bite
Planter boxes
- Pressure treated for legs that rest on stone or soil
- Thick fabric lines inside walls to keep dirt away from wood
- Redwood for the top rim where hands land
Fences
- Pressure treated posts in earth
- Redwood rails pickets and caps
- Gravel sits under each post to drain water
- Soil slopes away from posts
Pergola frames
- Pressure treated at the base where wood meets stone
- Redwood for beams rafters and lattice
- Tilt flat tops a touch so water runs away
Soil rules that save work
I once pulled redwood posts that looked firm above grade but felt like sponge where soil met air. Water loves that gap.
- Use pressure treated marked zero point four zero or higher for any soil touch part
- Keep soil lower than the top of concrete collars
- Place gravel under each post for fast drain
- Brush copper rich fluid on every cut end of pressure treated stock
Fastener guide
Copper salts chew at plain steel. Pick strong metal that lasts.
- Hot dipped galvanized nails and screws serve most yards
- Stainless steel shines near salt spray
- Coated deck screws stop streaks on redwood
- Drill pilot holes near ends of redwood to stop splits
Finish moves that add years
Pressure treated care
- Dry new boards then drip water to test soak time
- Scrub with cleaner then dry under sun for one day
- Brush on a deep oil or semi clear stain that blocks ultraviolet light
- Repeat on high foot paths every third year
Redwood care
- Start with boards that feel dry and show no mill shine
- Brush on clear or softly tinted oil
- Work oil in and wipe any pools
- Refresh every second year in full sun or third year in shade
I track tasks on a simple calendar.
- Early spring rinse decks and check screws
- Early summer sand tiny checks on redwood then oil clean faces
- Fall clean frames and remove leaf piles before snow
Cost and life chart
- Pressure treated. Low price and frames last many decades with steady care. Deck tops last near twenty seasons with wash and oil
- Redwood. Higher price and heart heavy boards reach thirty seasons above ground with oil care. Mixed grades age faster
Inside the treatment tank
The process looks like deep sea pressure but happens on land. Pumps pull five atmospheres of force that crams copper salt into every pore. A final vacuum removes free water so the board holds the salt yet weighs less. Fungi lose their grip when salts fill cell walls.
How redwood grows and why that matters
Fog rolls in each night and the tree drinks from the mist. Slow growth makes tight rings. The heart centers pack tannin which tastes bitter to bugs. That slow pace writes a natural shield in each ring. Fast grown sap around the edge lacks the same guard. Grade labels show that split.
Small shop cost sheet
I kept receipts from a porch swing build last month.
- Frame. Pressure treated pine ten boards at fourteen each total one forty
- Chain and hardware stainless set forty three
- Seat and back. Redwood heart common twelve boards at twenty eight each total three thirty six
- Oil and brush kit fifty
- Sand paper and small gear twenty
Whole cost landed at five eighty nine. Full redwood frame would pass eight hundred. Full pressure treated would save one hundred yet feel cold to touch.
Lessons from real builds
Lakeside dock stairs
Pressure treated pine stringers sit in lake water for fifteen years and still hold weight. Redwood treads swap every eight years because waves and sun hit hard.
City roof deck
Steel frame supports pressure treated joists that fight pooled rain. Redwood boards glow above city lights and need oil each third year.
Community garden beds
Volunteers used pressure treated sides lined with plastic. Redwood caps feel safe for hands that pick herbs. Beds stand firm after six hot summers with daily hose spray.
Cabin railing in snow
Metal posts hold redwood rails high above drifts. No pressure treated needed because rails stay dry yet oil goes on each autumn.
Brain style pick path
Think of your plan like the brain that works in layers. First you check water contact. Next you check looks. Then you scan cost. Each pass sharpens the choice like a soft gradient step in a laboratory model. A check after each pass keeps you true.
Future trends
Plant based salts arise in research laboratories and may replace copper soon. Clear seal that blocks ultraviolet light without color gains fans. Some mills grow redwood inland to spread supply. Bamboo composite keeps knocking yet many still trust real wood for feel.
Maintenance gear list
- Garden hose with gentle spray head
- Soft brush with long handle
- Mild powder cleaner
- One gallon of penetrating oil in warm tone
- Two inch brush with natural bristle
- Light gloves
- Knee pads
Good gear turns chores into quick tasks.
Sensory tests
Tap pressure treated board and the sound comes dull. Tap redwood and it rings bright. Smell the cut end and pressure treated smells like a copper penny. Redwood smells like sweet soil. Touch the surface and redwood feels warm even in shade while pressure treated feels cool and damp.
Myth bust list
- Pressure treated harms plants. Modern copper levels stay safe when used as bed walls
- Redwood never moves. It moves less yet still shifts so leave gaps
- All pressure treated wood works in water. Only high rate boards do
- Oil is not needed on pressure treated. Oil still blocks cracks and holds color
Craft tricks from veterans
- Cut a shallow kerf under board ends to break drip lines
- Use a speed square as a small spacer for even gaps
- Keep a dull chisel near deck slats to shave mill marks
- Wipe each screw head while oil stays wet to stop blotch rings
Advice for new builders
Start small with a planter box to learn the mix rule fast. Keep notes on oil dates. Snap photos under each season to watch color change.
Simple exposure chart
| Sun hours each day | Wood pick |
|—|—|
| Under four | Pressure treated frame plus construction common redwood skin |
| Four to seven | Pressure treated frame plus heart common redwood skin |
| Over seven | Pressure treated frame plus clear heart redwood skin with tinted oil |
Soil science
Wet soil holds air pockets that feed fungi. Gravel at the base cuts that air. Copper salts in pressure treated starve fungi. Tannin in redwood heart also works yet only above soil.
Memory trick
Color guides task. Green boards hide and fight while red boards show and charm.
Frame check routine
Each spring crawl under the deck.
- Look for dark stain lines
- Probe joist ends with a thin tool
- Tighten lag bolts
- Brush off leaf piles
Ten minutes can save ten hours later.
Snow care tip
Sweep fresh snow from decks to stop ice dam build up. Use plastic tools to avoid scars.
Healthy wood sound
Strike a post with a hammer and a clear ring means strong grain. A dull thud hints at rot.
Fire care
Redwood burns slower than pine yet all wood burns. Keep grills clear. Never burn pressure treated scrap because smoke holds copper salt.
Renter note
Modular deck panels made with the mix move with you. Pressure treated feet sit on lawn pads and redwood tops screw on.
Second life ideas
Old redwood boards turn into planter trim or wall art. Old pressure treated boards frame shed roofs after screw removal.
Quick shop shelf
Use pressure treated scraps for frame then skin with redwood strips. Spray clear coat and gain storage while testing finish mix.
Stacking rules
Keep pressure treated flat with spacers. Store redwood on edge to air both faces. Use a light tarp that breathes and avoid tight plastic wrap.
Tool kit for the mix
- Carbide blade for clean cuts
- Pocket hole jig for hidden screws
- Trim router with small round bit
- Moisture meter to test dry level
Finish color guide
- Warm amber lifts red tones in heart wood
- Honey brown masks green tint as pressure treated fades
- Clear oil keeps natural tone yet needs more coats
Talk with the lumber clerk
Ask the clerk to pull a fresh bundle if the stack looks rough. Check tag dates since older packs weigh less after dry time. Choose boards based on your build start day.
Science recap
Pressure treated wood gains defence from copper while redwood gains defence from tannin. Water time and sunlight decide which defence you need.
One weekend deck recipe
Project foot print eight feet by twelve feet.
- Footings and posts four by four pressure treated zero point four zero
- Beams and joists two by eight pressure treated
- Deck boards five quarter by six redwood heart common
- Rail posts pressure treated wrapped with redwood
- Rails redwood smooth edge
- Fasteners hot dipped galvanized for frame and coated screws for boards
- Finish light tinted oil on redwood and clear oil on green parts
Build with one helper over two days. Oil in one afternoon and repeat each second summer.
Missteps and fixes
- Soil grade wood used near earth. Swap to zero point four zero stock
- Posts set in solid concrete. Keep top of concrete low and fill cap with gravel
- End grain left bare. Paint with copper fluid
- Early stain on wet pressure treated. Wait for water test
- Sap heavy redwood on open deck. Move such boards under cover or use more oil
Indoor damp spots
- Avoid pressure treated on skin touch inside rooms
- Use kiln dried spruce and seal well
- Redwood fits bath ledges or plant stands when sealed
- Pressure treated plate sits on concrete with foam strip under
Top questions
- Is redwood better than pressure treated*
Redwood looks rich and stays stable so it rules visible parts while pressure treated stands firm in wet soil so it rules hidden frame.
- Is redwood good in soil*
Heart heavy redwood lasts above soil in dry air yet wet soil weakens it so pick pressure treated zero point four zero for that spot.
- What down sides come with pressure treated*
Boards arrive wet and can twist while green tint shifts stain shade and some metal rusts without coating.
- How long will bare redwood last outside*
Heart heavy redwood lives many decades when oiled while sap heavy boards fade faster.
Flow chart memory
- Soil touch picks pressure treated
- View touch picks redwood
- Deep shade picks pressure treated frame with wide gaps
- Warm tone wish picks redwood slats with amber oil
- Salt zone picks stainless metal with extra oil cycles
Glossary
- Heartwood. Dark inner core that holds oils
- Sapwood. Pale outer ring with little oil
- Preservative rate. Number on tag that shows pounds of salt in each cubic foot
- Penetrating oil. Finish that sinks into grain
- Hot dipped galvanized. Steel dipped in molten zinc
Why mixing wins
Pressure treated bones carry weight and laugh at water while redwood skin greets eyes and hands with warmth. You pay less and feel more. That result keeps builders happy.
Shop story wrap
Last season I built a planter bench for a friend. Pressure treated frame floated on rubber pads over the patio. Redwood slats wrapped the shell with neat shadow lines. We oiled every face before a single screw. Two days later rain danced on beads that rolled off. We sat with hot coffee and wide grins. That bench still feels fresh.
Yard checklist
- Read tag numbers on green boards
- Pick redwood with strong red edge and straight grain
- Buy hot dipped or stainless metal
- Grab end grain seal and a warm tinted oil
- Pack joist tape and slim rubber shims
Build order
- Cut parts and seal ends
- Drill holes near redwood ends
- Tilt flat faces a bit
- Leave even gaps for air
- Oil in shade and let it cure
Final word
You never need to crown a single winner in the debate on pressure treated wood vs redwood. Let each wood play its strong suit. Your deck or chair will stand firm and look sweet. Share photos of your next build. I live for shop talk.