Subfloor & Prep
The finish floor everyone walks on tomorrow only lays flat, glues down, locks together, and stays quiet because of the four prep services that happen first. The 1960s ranch in Ballard where the kitchen subfloor dips three-quarters of an inch from one cabinet run to the other and the new luxury vinyl plank reads every dip like a topographic map. The Madison Park 1924 craftsman where the downstairs powder room toilet has been weeping at the flange for years and the OSB underlayment is black with mildew. The Wallingford bungalow where the crew that installed the previous engineered hardwood in 2008 left the 4 mil polyethylene off the slab because the rolls were on a different truck and now the boards cup in every winter. The Ravenna split-level where the pulled-up carpet revealed a layer of 1972 vinyl glued to 1956 vinyl glued to original 1948 fir, and no flooring contractor will quote the install until somebody else demos the stack. Subfloor and prep is the trade family that resolves all of it before the finish goes down — subfloor leveling, subfloor repair and replacement, old flooring removal and disposal, and moisture barrier and underlayment. Handis self-performs every prep scope as core finish-carpentry work. From $500 for a small moisture barrier and underlayment install in a single room to $4,000 for a full repair-and-replacement scope on a sagging laundry-room sheathing.
Services
Subfloor & Prep Pricing
Final pricing depends on the room size, condition of the existing subfloor and finish floor, the depth of any dip or rot found on site, and the underlayment matched to the finish-floor warranty spec. Each child page lists detailed pricing for that prep family. Asbestos abatement (pre-1985 9x9 and 12x12 vinyl tile) is identified on the booking call and routed to a licensed abatement contractor; that scope is never quoted by Handis. Request a free estimate for an accurate quote.
Tell us the room and the condition under the old floor — we will quote leveling, repair, demo, and underlayment as one prep package before the finish floor goes down.
Why Seattle Homeowners Book Handis for Subfloor & Prep
Every failed flooring install we are called back to repair traces to a single shortcut at the prep stage. The flooring contractor who skipped the moisture meter on a slab and the new engineered hardwood cupped through the first wet Seattle winter. The big-box install crew who laid laminate over a half-inch dip and used the existing carpet pad as underlayment, and the boards now click apart at the seams under the table. The DIY tile job that went over the original 1956 vinyl without a decoupling membrane, and every grout line opens by year three. Subfloor and prep is the trade family that decides whether the finish floor lasts the full warranty life or fails inside five years — and it is the cheapest place to spend money on a flooring project because it never has to be done twice. Handis self-performs every prep scope; we name the underlayment and the manufacturer spec on every quote.
Estimate
Tell us the room (kitchen, bath, laundry, main floor, basement, upstairs), the rough square footage, what is on the floor now (carpet, vinyl, hardwood, laminate, tile, painted concrete, bare sheathing), and what is going down next (luxury vinyl plank, engineered hardwood, laminate, nail-down hardwood, tile). A phone photo of the existing floor and any visible dip or soft spot helps us quote leveling and repair scope without a site visit. We send a clear estimate with the prep package itemized — demo, leveling, sheathing repair, underlayment — separately or as a bundle.
What Our Customers Say
Recent subfloor and prep reviews from verified Seattle-area customers.
1962 ranch in Ballard. We pulled the carpet ourselves to save the demo fee and were going to do the new vinyl plank install ourselves too. Handis walked the floor with a straightedge and showed us a five-eighths-inch dip across the kitchen-dining run that we had not seen. They did a self-leveler pour, two sister boards on the joists at the worst spot, and the new floor went down flat. We would have read every dip through the plank for ten years.
Madison Park craftsman. The downstairs powder-room toilet had been weeping at the flange for years and the OSB under the tile was black. Handis cut out a four-foot square section, replaced the sheathing with 3/4-inch plywood, sealed it with the right primer, then retiled. No more soft spot, no more mildew bloom in the closet next door.
Wallingford bungalow kitchen demo. Pulled-up carpet revealed three layers — carpet pad, 1972 sheet vinyl, 1956 tile vinyl, original 1948 fir. The flooring installer said he would not quote the new floor until somebody else did the tear-out. Handis did the demo in two days with a HEPA scrubber, hauled everything in their truck, left the original fir subfloor clean and ready for the new install.
Ravenna split-level basement. We were laying engineered hardwood directly on the slab and the flooring shop sold us 3-in-1 underlayment with vapor barrier. Handis confirmed the slab moisture reading with a calcium chloride test before they laid the polyethylene under the foam, then installed both layers. First wet Seattle winter and the floor is dead quiet, no cupping at the perimeter.
Queen Anne 1924 second-floor renovation. We were installing nail-down hardwood and the contractor recommended cork underlayment for sound. Handis ordered the cork to the right thickness, rolled it tight over the rosin paper, taped every seam. Downstairs neighbor heard nothing during install and hears nothing now when we walk across the room.
Frequently Asked Questions
Common questions about Handis subfloor and prep work — scope, pricing, scheduling, what triggers a sheathing replacement versus a leveler pour, asbestos identification, and how prep ties into the finish floor warranty.