Framing Layout & Design
Spacing, rough openings, headers, and spans — the numbers that decide everything downstream.
Stud & wall specs
- Exterior walls
- 2x4 or 2x6 @ 16" O.C. — use 2x6 for plumbing walls and extra insulation
- Interior non-bearing
- 2x4 @ 16" O.C. (24" O.C. acceptable for non-bearing in some codes)
- Plumbing walls
- 2x6 minimum — shower valves and toilet flanges need the depth
- Corners / intersections
- California corner or ladder backing so both faces can be nailed and insulated
Rough opening rules
- Interior door
- R.O. width = door width + 2"; height = door height + 2½" (slab) or + 3½" (over finished floor w/ carpet & pad)
- Pre-hung door
- Use the door unit's listed R.O. — typically width + ½" to 1", height + 1½" to 2"
- Window
- Use manufacturer's R.O. exactly — check every unit; R.O.s vary between brands
- Shower / tub alcove
- Framing plumb and true to the fixture spec — tubs and pans are unforgiving; ½" out of square shows in every tile joint
- Curbless shower
- Recess or slope the subfloor early — planning for it after framing costs triple
Header sizing (rule of thumb)
Floor joist spans @ 16\" O.C.
| 2x8 | 16" O.C. | ≈ 12' – 13' |
| 2x10 | 16" O.C. | ≈ 15' – 16' |
| 2x12 | 16" O.C. | ≈ 18' – 19' |
| I-joist / floor trusses | 19.2" or 24" O.C. | Per manufacturer chart — always confirm with the span tables for your species/grade |
Confirm against your species/grade span tables — these are guides, not a substitute for the code book.
Layout tips from the field
- Snap plate lines on chalk lines — keep exterior corners square by measuring diagonals before you nail anything.
- Layout doors away from corner jog; leave room for trim casings (usually 3" min from a corner).
- Nail blocking mid-wall for chair rail, grab bars, TV mounts, and towel bars — cheap now, impossible later.
- Dry-lay bathroom walls early: valve depth, toilet flange (12" from finished wall), and curb height all get decided here.
- Fire-block every furred chase and soffit penetrations between living space and attic.
Rough-In & Trim-Out Heights
Standard placement heights — verify against local code and appliance spec sheets.
| Item | Standard height / rule | Notes |
|---|---|---|
| Wall receptacle | 12" to box top (12"–16" typical) | Max 12' between receptacles on a wall run; any wall 24"+ needs one |
| Countertop receptacle | ~44" / 3"–4" above backsplash | GFCI required; first within 2' of sink edge; one every 4' of counter |
| Switches | 48" to top (48"–52") | On the latch side of the door; keep consistent room to room |
| Thermostat | 52"–60" | Interior wall, away from direct sunlight, supply vents, and kitchen heat |
| Panel | Top of panel ≤ 6'7" | 36" wide x 30" deep clear working space in front, always |
| Smoke detector | Ceiling (4" from wall) or 4"–12" below ceiling on wall | Every bedroom, outside each sleeping area, one per level minimum; interconnected |
| Water heater disconnect | Within sight, eye level | Non-fused disconnect or breaker lock for electric units |
| Dryer / range outlets | Per appliance specs (often 4"–12" behind unit) | 4-wire on new builds; check cord vs outlet match at trim-out |
| Exterior receptacles | ≥ 12"–16" above grade, in-use covers | Front & rear of dwelling required; GFCI protected |
| Doorbell | 48" | Transformer on a dedicated accessible junction |
Shower Installation
Frame to trim-out, in order — water management first, tile second.
Pre-slope, weep holes, flood test, silicone. The #1 shower callback is water management, not tile — pre-slope, weep holes, flood test, and silicone at every change of plane.
- 1
Frame & prep
Curb at 4½"–5", blocking at 33"–36" for grab bars and benches, and a 2x10 or open stud bay where the valve goes. Dry-set the pan and check level both ways before anything is permanent.
- 2
Rough plumbing
Valve at 42" centered, shower head stub at 80". Pressure-test the valve before closing the wall — a failed solder joint behind cement board is a full tear-out.
- 3
Pan & liner
Pre-slope the subfloor at ¼" per foot to the drain before the liner goes down. Clamp the liner over the pre-slope, run it up the studs 6"–8" and over the curb in one piece, and keep the weep holes open with washed gravel.
- 4
Curb & dam corners
Use preformed dam corners at the curb ends — folding the liner there by hand almost always leaks.
- 5
Backer board
Cement board or foam board nailed to the flange line, with a ¼"–½" gap above the pan. Tape and mortar the seams. Never use drywall in a wet zone.
- 6
Waterproof
Two to three coats of liquid membrane (paint the seams, fasteners, and curb twice) or a fabric system. Flood-test the pan 24–72 hours before tile — this is the single step that saves callbacks.
- 7
Tile & grout
Floor tile pitches to the drain. Keep grout joints in wet floors at ⅛"–¼" sanded. Never grout the change-of-plane joints (pan-to-wall, corner-to-corner) — those get 100% silicone.
- 8
Trim out
Install the finish trim, seal plane changes and fixtures with silicone (match the grout color), and run the shower full-flow for 5 minutes watching the ceiling below.
Tile & Flooring Finish Work
Prep, layout, joints, and transitions — the details that separate a show job from a callback.
Subfloor & prep
- Tile floors need deflection of L/720 in wet areas (stiff, not just strong) — add blocking or a second layer before you blame the mortar.
- Substrate must be flat within ⅛" per 10 feet — self-level or mud it. Flatness failures cause more cracked tile than anything else.
- ¾" T&G subfloor + cement board (mortared and screwed) or an uncoupling membrane for standard installs.
Layout
- Dry-lay and snap control lines from the room's main sightline (usually the entry) — don't start from a corner.
- Large-format tile (16"+): use a ⅓ offset pattern, not 50%, and an anti-lippage system.
- Undercut door jambs and casings so tile slips underneath — cuts at the casing always show.
Grout & joints
- Rectified tile: ⅛" joints are fine. Standard edge tile: ¼"–⅜". Never butt joints.
- Sanded grout for floors and joints over ⅛"; unsanded for walls and thin joints.
- Seal cementitious grout after full cure; caulk (not grout) every plane change.
LVP & wood-look flooring
- Acclimate 48 hours in the room; check slabs for moisture before floating anything.
- ¼" expansion gap at all walls and verticals — LVP needs to move; use T-molding over 30–40 ft runs.
- Stagger end joints 6"–8" apart and never repeat the same plank sequence — patterns are visible.
- 1/8"–3mm underlayment over wood subfloors; check the LVP brand — some have it attached.
Transitions
- Match heights before you pour: tile, mud bed, and LVP stack to different finished floor heights — plan the transition strips before install.
- Schluter-type edge profiles for tile-to-LVP and tile-to-carpet; T-strips for equal heights.
- In bathrooms, keep tile higher than LVP run-off — never let water shed onto a floating floor.
What to Include in the Bid
Line-item checklists per trade — drop these straight into a customer bid so nothing gets missed.
Framing package
- Plan review & permit fees
- Lumber + engineered lumber takeoff
- Layout, snap lines, plate walls
- Frame floors, walls, roof
- Headers, beams, posts, hardware
- Sheathing & house wrap
- Backer/blocking for future fixtures
- Waste haul & clean-up
Tile & flooring
- Demo & haul-off of old floor
- Subfloor prep / flatness correction
- Backer board or uncoupling membrane
- Waterproofing (wet areas)
- Tile labor per square foot + trim pieces
- Grout, transition strips, thresholds
- Grout sealing
Shower install
- Demo to studs & inspection
- Valve rough-in & pressure test
- Pan, liner, curb, dam corners
- Waterproofing + flood test
- Wall tile, bench, niche
- Glass door/panel (often separate line)
- Fixture trim & silicone
Plumbing trim-out
- Angle stops at every fixture
- Toilet, vanities, faucets set
- Shower/tub trim installed
- Water heater hook-up + T&P discharge
- Fixture testing under full flow
Electrical trim-out
- Devices, switches, plates
- Lighting & ceiling fans
- Panel breakers labeled
- Smoke/CO detectors set
- GFCI/AFCI test & punch walk
