Inside: washing, sanding, filling and when we prime
Interior prep starts with a raking light and a sanding sponge. Every wall gets checked for holes, pops and cracks, and those get filled or taped and sanded flush. Glossy surfaces, which means trim, doors, cabinets and any wall in a semi-gloss, get scuff sanded so the new coat has something to grip. Kitchens and bathrooms get washed with a degreaser because paint will not bond to cooking film or soap scum. Then the primer decision. Bare drywall, patches, stains, dark-to-light color changes and slick trim all get primer. A clean wall in good shape getting a similar color usually does not. We tell you which walls are being primed and why, since it is a real cost and a real difference.
- Raking-light inspection, then fill, tape and sand
- Scuff sand anything glossy: trim, doors, cabinets
- Degrease kitchens and baths before any primer
Outside: scraping, moisture readings and priming bare wood the same day
Exterior prep in Minnesota is a race against moisture. We wash the house first to remove chalk, mildew and dirt, then wait for it to dry, which on a shaded north wall can be a day or more. Loose paint gets scraped and the edges feathered with a sander. Then we check the wood with a moisture meter. Wood siding and trim above the mid-teens in percent moisture content will push water out through fresh paint and blister it, so we wait or move to the sunny side. Bare wood gets primed the same day it is exposed, because weathered wood loses its ability to hold paint within days of sun exposure. Caulk goes on after primer, at joints and around windows, and then the topcoats follow.
The primers we reach for and what each one solves
There is no single primer, and using the wrong one is nearly as bad as skipping it. Drywall primer seals new board and patches so the finish sheen is even. Bonding primer grips slick surfaces: varnished oak, glossy trim, old cabinets, fiber cement with a factory finish. Stain-blocking primer, usually a shellac or oil base, seals water rings, smoke, tannin bleed from cedar and the marker on a kid's wall so it cannot migrate through. Exterior oil or alkyd primer soaks into weathered wood and gives the topcoat a stable base. Tinted primer under deep colors saves a coat. We carry all of them and choose per surface. Generic categories are named here on purpose; the specific products change as the manufacturers do.
When we would talk you out of it
- Surfaces where the substrate itself has failed: rotten trim, delaminating hardboard, soft drywall. Prep cannot save those. Replacement first, then we prime and paint the new material.
- Lead paint abatement in pre-1978 homes. We can work around intact old paint with safe practices, but stripping or removing lead paint is a separate certified trade.
- A homeowner who wants to skip prep to save money. We will not paint over a surface we know will fail, because the callback costs both of us more than the prep would have.
What you get
- Every surface inspected under a raking light before anything is filled
- Moisture meter readings on exterior wood before primer goes on
- Bare wood primed the same day it is exposed
- Bonding primer on oak, glossy trim and factory finishes
- Stain-blocking primer on water, smoke and tannin marks
- Prep steps listed on the written estimate so you can compare
How it goes
- 1
Inspect and sort the surfaces
Each surface gets sorted by what it needs: fill, sand, wash, scrape, prime. That list goes on the estimate so you know what is included before we start.
- 2
Clean and repair
Interior walls washed where needed and patched. Exterior surfaces pressure or hand washed, scraped, sanded and checked with a moisture meter before anything else.
- 3
Prime by surface type
Drywall, bonding, stain-blocking, exterior alkyd or tinted primer, chosen per surface. Bare exterior wood is primed the same day it is exposed to the weather.
- 4
Caulk, then finish coats
Caulk goes on over primer at joints, corners and around windows and trim. Then the finish coats, with a light sand between coats on trim and cabinets.
How much does surface prep add to a painting job?
Prep is not a separate price on most jobs; it is inside the painting estimate as the line items that make the number what it is. What we can say is where it moves the total. Interior prep is light on clean walls in good shape and heavy on rooms with a lot of damage, glossy trim, or stains that need a sealing primer. Exterior prep is the majority of the labor on a repaint: washing, scraping, sanding and priming bare spots take longer than the topcoats. A house with peeling on several sides costs far more to prep than one with sound paint that just faded. We show prep as its own lines so you can compare our estimate with another painter's honestly.
- Condition of the existing paint or finish
- Amount of patching, taping and sanding needed
- Glossy or varnished surfaces that need scuffing and bonding primer
- Stains that need a sealing primer
- Exterior washing, scraping and moisture wait times
- Whole-surface priming versus spot priming
Questions we get on the phoneStraight answers.
Do you always need to prime before painting?
No. New drywall, patches, stains, bare wood, glossy trim and big color changes need primer. A clean painted wall in good shape getting a similar color usually does not, and a good paint will bond fine. The mistake is guessing. We check each surface and tell you which ones are getting primer and why on the estimate.
What happens if you paint over dirty walls?
The paint bonds to the dirt instead of the wall, and the dirt lets go later. On kitchen walls this shows up as peeling near the stove within a year. On exterior siding, chalk and mildew under new paint cause the same failure across whole walls. Washing is cheap. Repainting a failed wall is not.
How do you know if exterior wood is dry enough to paint?
With a moisture meter. We pin the wood in several spots per wall, and if it reads above the mid-teens in percent moisture we wait or move to a drier side of the house. A north wall after a wash or a rain can hold moisture for a day or more. Painting wet wood traps water that blisters the finish.
Can you paint over peeling paint if you scrape the loose parts?
Scraping loose paint is the first step, not the whole answer. The edges left behind have to be feathered with a sander so they do not telegraph through, and the bare wood needs primer the same day. Paint applied over a scraped edge without sanding and primer will lift at that edge within a season.
Related
Where we do this work
Prep and priming across Independence, Medina, Corcoran, Orono, Wayzata, Plymouth, Maple Grove and Minnetonka, and the rest of the west metro and Central Minnesota. See the full service area.