Reclaimed Heart Pine Floor Restoration with Wide Gap Filling in Big Canoe, GA
Classy Flooring ATL restored a 1,200 square foot reclaimed heart pine floor in Big Canoe, Georgia, with board gaps measuring from approximately 1/8 inch to 5/8 inch. Every gap was filled with Berger-Seidle AquaSeal PAK-Stop, a high-elastic trowel filler that remains flexible after curing and accommodates seasonal board movement. The filler was colored on site with AquaSeal Pafuki Powder and troweled edge to edge across the full floor in two coats, 24 hours apart. No joint required a third coat, including the widest at 5/8 inch. The floor had also been sanded close to the tongue during a previous refinish, which left more than 75 locations of lifted and splintered wood. Classy Flooring ATL bonded each of those repairs with cyanoacrylate glue and spray activator. No boards were replaced anywhere on this floor. The project totaled 2,400 square feet across three species and was completed by a three-person crew in ten working days.
Project Overview
This project covered three separate hardwood floors in one home: 1,200 square feet of century-old reclaimed heart pine, 950 square feet of new southern yellow pine that had never been sanded, and 250 square feet of existing white oak herringbone. The heart pine carried the conditions that defined the project — wide board gaps, a failed oil-based polyurethane, splintering along board edges and ends, and a wear layer already reduced by more than half during a previous refinish. The southern yellow pine and the white oak were finished with a second stain color selected to bring all three floors to the same tone, so the house reads as one continuous floor across doorways where no transition strips are installed.
This Big Canoe project is one of Classy Flooring ATL’s documented hardwood restoration projects — wide-gap filling, splinter stabilization, and multi-species color matching on reclaimed heart pine. See the full range of our work on our Our Work page.
Project type: Hardwood floor refinishing and restoration — no floor installation
Location: Single-family home, Big Canoe, Georgia
Scope: 2,400 square feet — reclaimed heart pine, new southern yellow pine, white oak herringbone; basement stair treads and risers included; basement floor not in scope
Crew: Three, Classy Flooring ATL in-house
Duration: 10 working days
Year: 2026
Starting Condition
Reclaimed heart pine — 1,200 sq ft. Kitchen, dining, living room, enclosed porch, garage hallway with bathroom, and a secondary hallway. Over a century old and finished in an oil-based polyurethane that had failed. The floor was not flat. Board gaps measured from approximately 1/8 inch to 5/8 inch.
This floor had been refinished before and taken down close to the tongue: on most boards, more than half of the wood above the tongue was gone. Where that layer becomes thin, the board edges lose support and begin to lift and splinter, and that condition was present at more than 75 locations on this floor. NWFA’s sand-and-finish guidelines put the general limit at 3/32 of an inch, about 2.4 millimeters, of wood above the tongue — below that, a floor generally should not be sanded — and splintering edges are one of the visible signs that a floor is getting close to it. The sanding sequence on this floor was planned around the wood that remained.
Southern yellow pine — 950 sq ft. Master bedroom, master closet, and rear office. A new floor that had never been sanded. This area required finishing, not refinishing.
White oak herringbone — 250 sq ft. Entry hallway. Existing floor, refinished.
The subfloor was sound throughout with no structural issues found. The floors run directly into one another with no transition strips at the species changes. The home was unoccupied for the duration of the work.
The homeowner had been advised previously that the gaps in the heart pine could not be addressed.
Why the Gaps Were Filled on This Project
Board gaps in a plank floor are not automatically a defect. Narrow, stable, evenly distributed gaps are a normal characteristic of plank flooring and are frequently left open. Filling becomes appropriate when the gaps are wide enough to collect debris and catch furniture, when the gap widths across the floor are irregular, or when the floor is being fully refinished and the gaps would otherwise remain the one unaddressed condition.
Wide joints can be closed in several ways, and each one behaves differently.
Rope or jute pressed into the gap closes the void. It does not produce a continuous surface that can be sanded and finished with the floor.
Wood slivers cut and glued into the joint are the method NWFA’s sand-and-finish guidelines list for larger gaps, closing the joint with wood.
Sawdust mixed with glue is suited to hairline joints. In a joint measured in eighths of an inch, the mixture shrinks as it dries and can settle below the surface and release as the boards move.
Rigid commercial filler cures hard. As the boards move, it can release from one board face or fracture through the middle.
Wood is hygroscopic and responds to seasonal humidity regardless of what occupies the gap. On this floor, with joints from 1/8 inch to 5/8 inch across 1,200 square feet, we presented the homeowner an elastic filler that remains flexible after curing and moves with the boards, and she chose it.
How This Project Was Executed
- Evaluated the floor and measured the gap widths across the reclaimed heart pine
- Built two pine sample pieces in the shop, filled with AquaSeal PAK-Stop and AquaSeal Pafuki Powder, and applied stain colors to them
- Presented the sample pieces to the homeowner for approval of the filler color and stain direction
- Opened the heart pine with the first cut at 36 grit
- Bonded 75+ splintered and lifted board sections with Stick Fast cyanoacrylate glue and spray activator
- Completed the sanding sequence to receive filler — 60 grit with the belt machine, then 60 grit with the planetary sander
- Mixed AquaSeal PAK-Stop with AquaSeal Pafuki Powder in black and troweled it edge to edge across the full floor
- Allowed 24 hours, applied a second full coat, allowed a further 24 hours
- Sanded the cured filler back — 36, 60, 80, then 100 and 120 with the planetary sander
- Sanded the new southern yellow pine — 40, 60, 80, then 100 and 120 with the planetary sander
- Sanded the white oak herringbone through the same sequence as the plank floors
- Placed three stain samples at the junction of the two pine floors for homeowner selection
- Applied a thinned dewaxed shellac wash coat to the pine before staining
- Stained the heart pine in DuraSeal Jacobean and the yellow pine and white oak in DuraSeal Espresso
- Applied one coat of Berger-Seidle AquaSeal FlexSealer
- Applied two coats of Berger-Seidle AquaSeal CeramicStar in satin
- Installed new white primed quarter round throughout
Splinter Repair and Board Stabilization
The splinter repairs were carried out after the first sanding cut. The failed oil-based polyurethane concealed the condition of the board edges, and the full extent of the lifted and splintered material was only visible once that finish came off. Sequencing the repairs after the first cut also means the bonded splinters are sanded flat during the passes that follow.
On most of this floor more than half of the wood above the tongue was gone, and the board edges had begun to lift and splinter as a result.
Removing and replacing the affected boards was considered and set aside. Reclaimed heart pine of this age, grain, and color cannot be matched from current stock, and a replacement board remains visible in the finished floor. Board removal also opens new joints in a floor where the joints were the primary condition being corrected.
Each splinter was bonded back into place with Stick Fast cyanoacrylate glue and spray activator. Thin cyanoacrylate wicks under a lifted splinter and into the fracture. The activator cures it within seconds, so the splinter can be held in position and the crew can move to the next repair without clamping. The cured repair sands flush and takes stain with the surrounding wood.
More than 75 locations were repaired. The work occupied one full day of the ten-day schedule. No boards were replaced.
Sanding Heart Pine
Heart pine is the heartwood of longleaf pine and carries a high resin content, and NWFA’s species guide notes that the resin clogs sandpaper. That resin affects the sanding in two ways. The abrasive loads with pitch and stops cutting before the paper has physically worn out. The resin also transfers onto the drum inside the machine and hardens there.
On this floor the machines were stopped, the drums disassembled, cleaned, and reassembled approximately seven times over the course of the job. This is a standard condition when sanding heart pine and it accounts for a measurable portion of the labor on a floor of this species.
The heart pine was opened at 36 grit, where oak of comparable condition would be opened at 40. NWFA’s species guide notes that higher-resin heart pine may require a lower starting grit and a steeper first-cut angle. In our experience, the resin loads finer paper before it cuts through the old finish. On a floor already sanded thin, the passes after that first cut are planned to remove the failed finish and the surface irregularity while taking as little wood as possible.
Equipment: Lägler Hummel belt machine, Lägler Flip for cabinet toe kicks and confined areas, edger for perimeters, FG Floortec Discus planetary sander for the finishing passes. All corners were scraped by hand. All sanding was dustless.
Gap Filling — AquaSeal PAK-Stop
Berger-Seidle AquaSeal PAK-Stop is a high-elastic trowel filler produced for closing wide joints, and the manufacturer lists plank flooring as a suitable application. It is supplied colorless and is colored on site with AquaSeal Pafuki Powder, available in seven shades: oak, beech/red oak, maple/ash/pine, wenge/smoked oak, azobe/teak, white, and black. Black was selected for this floor. The product is also certified to block polycyclic aromatic hydrocarbons emitted by historic adhesives beneath old wood floors.
Preparing the floor to receive filler. The manufacturer specifies that PAK-Stop is troweled onto a floor sanded to a 60, 80, or 100 grit profile. That requirement set a full sanding sequence before any filler was mixed: 36 grit and 60 grit with the belt machine, followed by 60 grit with the planetary sander. The planetary pass produces a uniform surface across the whole field, so that filler troweled edge to edge stays in the joints and is not driven into open grain across the face of the boards.
Mixing and application. The powder was stirred into the compound immediately before use and worked to a homogeneous, trowelable paste at one part powder to five parts liquid, the working ratio used on this floor. The manufacturer’s published mixing example uses a richer powder loading. The paste was applied with a flexible steel trowel across the entire floor surface. Edge-to-edge application produces continuous contact through every joint across the floor.
Two coats, 24 hours apart. The manufacturer states that shrinkage in very large joints during drying is normal and that a second coat is applied after an overnight dry. On this floor the first coat consolidated and settled slightly below the surface in the widest joints as it cured. The published sanding window for PAK-Stop is approximately 14 to 16 hours at 73°F and 50% relative humidity, and Berger-Seidle notes that drying on very oily wood species can take up to 36 hours; a full 24 hours was allowed at each stage. No joint required a third coat, including the widest at 5/8 inch. Three 4.5 kg units of PAK-Stop were consumed across the 1,200 square feet.
Removing the filler. Filler applied across the whole floor is then sanded back off: 36, 60, 80, then 100 and 120 with the planetary sander. What remains is filler in the joints only, level with the surrounding boards, with the wood surface clean and open for stain.
Stain Preparation on Pine
Pine has a pronounced density difference between its soft early wood and its dense late wood. Stain applied directly to unprepared pine penetrates the early wood heavily and sits on the late wood, which produces a mottled result. Dark stain colors make the effect more visible.
Before staining, the pine received a wash coat of dewaxed shellac thinned five parts denatured alcohol to one part Zinsser SealCoat. Thinned dewaxed shellac is a standard pre-stain treatment for controlling uneven stain penetration on softwoods, and the manufacturer publishes this use for pine. The cut used on this floor is lighter than the manufacturer’s general recommendation; in our practice, a heavier film on a floor restricts stain uptake past the point of regulating it. The floor was left 12 hours before stain was applied.
Color Matching Across Three Species
The house contained three woods with three distinct appearances: century-old reclaimed heart pine with heavy figure and an amber undertone, new southern yellow pine that was pale and uniform, and white oak herringbone with open grain and a different figure.
A single stain color applied to all three would not have produced a match. Different species, and different ages of the same species, carry an identical stain to different results.
Two stain colors were selected to arrive at a common tone:
Reclaimed heart pine — DuraSeal Jacobean
Southern yellow pine and white oak herringbone — DuraSeal Espresso
Espresso on the new yellow pine produces the tone that Jacobean produces on the century-old heart pine. The relationship was verified on site.
Sampling
Sampling was carried out in two stages, beginning before any work started on site.
Two pine sample pieces were built in the shop. The gaps in them were filled with AquaSeal PAK-Stop colored with AquaSeal Pafuki Powder, and stain colors were applied over the filled surface. Building the samples in the shop meant the homeowner could evaluate the filler color and the stain over it on real wood, in combination, before the filler was applied across 1,200 square feet of floor.
Stain was then sampled on the floor itself. Three samples were placed at the junction where the reclaimed heart pine meets the southern yellow pine, the one location in the house where both species could be evaluated side by side under the same light at the same time. The homeowner selected from those three. Because the floors run directly into one another with no transition strips, the color relationship was resolved before any stain was applied.
The Finish System — AquaSeal FlexSealer and CeramicStar
The sealer and finish on this floor are Berger-Seidle, applied over a DuraSeal stain and a dewaxed shellac wash coat.
Sealer — AquaSeal FlexSealer, one coat. FlexSealer is a highly elastic single-component waterborne sealer formulated to reduce sidebonding and panelization, and the manufacturer recommends it for plank floors and for floors subject to movement. On this project it allows the floor to move seasonally without transferring stress into the finish film. It was applied in one uniform coat with the grain, worked richly enough to penetrate into the joints.
Finish — AquaSeal CeramicStar, satin, two coats. CeramicStar is a two-component waterborne polyurethane reinforced with ceramic particles, which the manufacturer positions for high-traffic floors and the renovation of old floors. Berger-Seidle’s US data sheet calls for final sanding to a 100/120 grit profile, which this floor received, and lists FlexSealer among the sealers to use beneath it when sidebonding is a concern. It was catalyzed with its own hardener at the specified 10:1 ratio and applied in two coats over the FlexSealer. Satin sheen throughout. The product is also produced in ultramat and semigloss.
The same sealer and finish were applied to all three floors.
Quarter Round, Stairs, and Additional Scope
The existing baseboards were retained. New white primed quarter round was installed throughout, supplied primed and left uncaulked and unpainted. Finish paint was outside our scope.
The old pine treads on the basement stairway were removed and 16 new oak treads and risers were installed, stained espresso to coordinate with a prefinished engineered floor installed in the basement by a separate contractor.
The Result
The finished floor is 2,400 square feet across three species reading as one continuous surface. Every gap in the reclaimed heart pine is filled flush with the surrounding boards, including the widest at 5/8 inch, in a filler that remains elastic and moves with the floor. More than 75 splintered board sections are stabilized and sanded flush with the surrounding wood, with no replacement boards anywhere in the house. The century-old heart pine, the new southern yellow pine, and the white oak herringbone carry the same tone from room to room, across doorways where no transition strips are installed.
Ongoing Maintenance
The finish is Berger-Seidle AquaSeal CeramicStar, a two-component waterborne polyurethane. NWFA directs that a site-finished floor is cleaned only with the cleaners the finish manufacturer recommends; for CeramicStar, Berger-Seidle names Brilliance Cleaner L94. Wax, oil soap, and general household cleaners are not used on this finish.
- Sweep, dust-mop, or vacuum regularly — on a hard-floor setting with the beater bar off — to remove grit that wears the surface.
- Clean with a microfiber mop only slightly dampened and well wrung out, using Brilliance Cleaner L94. A traditional mop and bucket and steam cleaners stay off wood floors, per NWFA.
- Place floor mats at each entry, as Berger-Seidle recommends, and felt protectors under furniture legs.
- Hold the house at 30–50% relative humidity and 60–80°F year-round — NWFA’s range when the flooring manufacturer doesn’t specify one — to limit seasonal movement.
Berger-Seidle’s data sheet calls for 24 hours before the floor takes traffic, and no rugs, carpets, or care products for seven days. Humidity control carries additional weight on a floor with filled wide joints, because the width of every joint responds to indoor humidity.
Project Specifications
Reclaimed heart pine: 1,200 sq ft — kitchen, dining, living room, enclosed porch, garage hallway and bathroom, secondary hallway
Southern yellow pine: 950 sq ft — master bedroom, master closet, rear office, new floor never sanded
White oak herringbone: 250 sq ft — entry hallway
Total area: 2,400 sq ft
Gap range, heart pine: approx. 1/8″ to 5/8″
Gap filler: Berger-Seidle AquaSeal PAK-Stop with AquaSeal Pafuki Powder, black
Filler mix ratio, as used on this project: 1 part powder to 5 parts liquid
Filler application: Flexible steel trowel, edge to edge, two coats 24 hours apart
Filler consumed: 3 × 4.5 kg units
Sanding to receive filler: 36, 60, then 60 planetary
Sanding after filler, heart pine: 36, 60, 80, then 100 and 120 planetary
Sanding, southern yellow pine: 40, 60, 80, then 100 and 120 planetary
Board repairs: 75+ splinter repairs, Stick Fast CA glue with spray activator
Boards replaced: None
Pre-stain treatment: Dewaxed shellac wash coat — 5 parts denatured alcohol to 1 part Zinsser SealCoat
Stain, heart pine: DuraSeal Jacobean
Stain, yellow pine and white oak: DuraSeal Espresso
Sealer: Berger-Seidle AquaSeal FlexSealer, one coat
Finish: Berger-Seidle AquaSeal CeramicStar, satin, two coats, catalyzed 10:1
Return to traffic: 24 hours per finish manufacturer
No rugs or floor care products: 7 days per finish manufacturer
Equipment: Lägler Hummel, Lägler Flip, edger, FG Floortec Discus planetary sander
Dust control: Dustless sanding throughout
Perimeter trim: New white primed quarter round
Trim finish paint: Not in scope
Stairs: 16 oak treads and risers installed, espresso
Crew: Three, Classy Flooring ATL in-house
Duration: 10 working days
Project type: Refinishing and restoration
Location: Big Canoe, GA
Completed by: Classy Flooring ATL
Frequently Asked Questions
How can I fill gaps in my pine floorboards?
For wide joints in pine, with an elastic filler troweled across the whole floor during a full sanding — that is our method. NWFA’s sand-and-finish guidelines set the ground rules for any filling: vacuum the gaps out first, press the filler into the joint rather than bridging over it, make sure the boards are tight, since loose boards won’t hold filler, let the filler dry fully before the final sanding, and don’t fill seasonal gaps in the dry season, because the wood swells back and damages the floor. On this floor the heart pine was sanded to the profile Berger-Seidle specifies for its AquaSeal PAK-Stop, the filler was colored black with AquaSeal Pafuki Powder and troweled edge to edge across all 1,200 square feet, and a second coat followed after the first had cured, as Berger-Seidle directs for very large joints. The cured filler was then sanded back off, leaving it only in the joints, flush with the boards.
What is the best filler for pine floorboards?
For wide gaps in pine, an elastic filler that stays flexible after it cures. Pine boards keep moving with the seasons, and a filler that cures hard — standard wood filler, or sawdust mixed with a binder — shrinks out of a wide joint, cracks, or releases from one board face as the boards move. On our pine floors we don’t use standard wood filler in the gaps. NWFA’s guidelines list slivers of wood for larger gaps on a sound floor; for an elastic filler, the manufacturer’s data sheet governs. Berger-Seidle describes AquaSeal PAK-Stop as a permanently high-elastic trowel filler, colored and hardened with its Pafuki Powder, and it closed the 1/8- to 5/8-inch joints on this floor. Our earliest floor with this system dates to January 2026; as of August 2026 it had come through the change from winter to summer with no joints opening and no filler releasing.
How big of a gap can you fill with wood filler?
A narrow one. Berger-Seidle’s own data sheets put its standard wood fillers at joints up to about 2 millimeters — under 1/8 inch — and direct anything wider to be closed with pieces of wood or an elastic filler such as AquaSeal PAK-Stop. In a wide joint, a rigid filler shrinks as it dries and can’t follow the boards as they move. On this floor the joints ran from about 1/8 inch to 5/8 inch and were closed with PAK-Stop in two coats. 5/8 inch was the widest, and we have not filled a wider joint with this system, so we don’t state a limit above it.
What causes gaps in floorboards?
In most homes, seasonal moisture. Wood takes on and gives off moisture with the indoor humidity and moves across its width as it does, so gaps open in the dry, heated months and close again in the humid ones; NWFA treats these seasonal gaps as normal. Gaps that are much wider, or that don’t close, point to something else — NWFA’s diagnostic guide lists causes such as the wrong fastener or nailing schedule on a nail-down floor, and flooring and subfloor that weren’t at matching moisture when the floor was installed. Holding the house at 30–50% relative humidity, NWFA’s range when the flooring manufacturer doesn’t give one, keeps the movement smaller. The reclaimed heart pine in this house had joints from about 1/8 inch to 5/8 inch, wide and irregular enough that an elastic filler was the right way to close them.
Can old pine floors be refinished?
Yes, as long as enough wood remains above the tongue. NWFA’s sand-and-finish guidelines put the general limit at 3/32 of an inch, about 2.4 millimeters: below that, a floor generally should not be sanded. The signs that a floor is getting close are visible before any sanding — fastener heads showing at the surface, edges splintering, tongues showing at doorways or vents — and the wood above the tongue can be checked at an exposed board edge, such as a vent cut or a threshold. This floor had been sanded thin by a previous refinish: on most boards more than half of the wood above the tongue was gone, and edges had splintered at more than 75 locations. It was refinished with every original board kept in place, the splinters bonded with cyanoacrylate glue after the first cut, and the sanding planned around the wood that remained.
How do you bring old wood floors back to life?
Match the work to the wear. When the finish is dull but intact and the wood under it is sound, a maintenance recoat — the finish abraded and a fresh coat applied — renews it without sanding; NWFA names that as the step when a floor loses its luster. A full sanding to bare wood is for what a recoat can’t fix: NWFA reserves it for dents, wear patterns, permanent cupping, or a change of color, and gaps, splinters, and a failed finish start there too. Products sold to restore, rejuvenate, or add shine are on NWFA’s list of things not to use unless the finish or flooring manufacturer recommends them. This floor needed the full restoration: the oil-based polyurethane had failed, the joints were open from 1/8 to 5/8 inch, and edges had splintered, so it was sanded to bare wood, filled, repaired, stained, and finished with one coat of Berger-Seidle AquaSeal FlexSealer and two coats of AquaSeal CeramicStar in satin.
Related Work
For pine and heart pine floor refinishing and restoration — wear layer, blotching, gap filling, and finish selection — see our Pine and Heart Pine Floor Refinishing and Restoration service page.
For another heart pine floor — color rebuilt to the amber it carried before a previous refinish, and a surface left uneven by that work corrected — see our Heart Pine Floor Refinishing project in Roswell.
For hardwood floor refinishing and restoration using professional finish systems, including wide-gap filling, splinter stabilization, and multi-species color matching, see our Hardwood Floor Refinishing & Restoration service page.
For a white oak refinishing project with lace-in repair and color matching between new and existing material, see our White Oak Floor Refinishing and Lace-In project in Buckhead.
If you have a reclaimed heart pine, antique pine, or wide-plank floor with open gaps and are deciding between restoration and replacement, contact Classy Flooring ATL to have the floor evaluated. Classy Flooring ATL serves homeowners and builders in Atlanta, Canton, Alpharetta, Milton, Roswell, Johns Creek, Buckhead, Sandy Springs, Brookhaven, Dunwoody, Braselton, Big Canoe, and surrounding North Georgia communities.