Historic Zoning Commission

Old North Knoxville H: Level II

9-B-21-HZ

Applicant Request

Porch rehabilitation project.

Flooring: replacement of wood tongue-and-groove flooring with wood tongue-and-groove porch flooring.

Columns: replacement of four round wood columns with four round fiberglass columns. Applicant will select replacement columns with diameter (approximately 10" at base), height (96"), and general design to match existing columns. Replacement columns will use square bases and Tuscan capitals to match existing.

Porch stairs: removal of existing wood handrail and wood flooring overlay on concrete steps. Existing steps are 5.5' wide and will be extended to 10' wide, spanning the width of the two rightmost columns. The steps will be flanked by two 13" thick cheek walls, constructed of brick and clad in plaster to match the existing stuccoed foundation. The cheek walls will be as tall as the porch foundation (approximately 24" tall).

CONDITION OF APPROVAL from 9/16/2021 HZC MEETING: 1) applicant submit to final specifications for column replacements (including capitals and bases, as necessary) to staff to ensure the new elements reflect existing in size, design, texture, and finish. Replacement columns to match specs submitted 8/1/22.

Site Info

Two-story frame residence featuring a hipped roof with lower cross gables extending toward the front and rear, clad in asphalt shingles. Property features wood siding and a brick foundation. One-story porch extends full length of the façade and features flat roof, wide cornices, and round wood columns. Façade windows are two-over-two double-hung wood sash with wood trim. Front gable features wood fishtail shingles, a round louvered vent, and decorative gable trim.

1. 317 E. Oklahoma Avenue is a contributing resource to the ONK National Register Historic District and local overlay.

2. The house has received a significant amount of exterior restoration since it was originally surveyed in the late 1990s and early 2000s. Restoration scopes completed in 2004 included the removal of artificial siding; repair and replacement to wood lap siding, including decorative shingle siding in the gable; and removal of the front porch enclosure which extended the length of the front gable massing, approximately half of the façade. The front porch restoration included the installation of at least two round wood porch columns to match the two rightmost existing, and new tongue-and-groove porch flooring. Additional work was completed in 2010 (including replacement of porch flooring), and a rear addition was built in 2019.

PORCH FLOORING
3. The applicant has provided documentation of the wood tongue-and-groove porch flooring's deterioration due to rain damage and sun exposure, especially along the front edge of the porch.

4. The proposed material, Aeratis Traditions composite flooring, is almost identical to the Aeratis Heritage composite flooring material which has been previously approved on 240 E. Scott Avenue (August 2018) and 215 E. Oklahoma Avenue (August 2020). The material is solid extruded PVC planks, which are faux-wood-grained to simulate wood flooring. The Aeratis flooring system can be completed with a chamfered- half-round, or quarter-round nosing as an edge trim.

Previous approvals have noted that the Aeratis composite materials are high-end composite flooring materials that sufficiently match wood tongue-and-groove flooring in design, color, texture, and visual qualities. The size of the tongue-and-groove floorboards are comparable to historic wood tongue-and-groove floorboards. Aeratis Traditions is a paint-ready material that will be painted to match the house (and thus, reduce any sheen that may differ from wood flooring). Moreover, the front porch on the subject property set significantly far back from the street and elevated somewhat from the sidewalk, so it will be minimally visible from the right-of-way.

PORCH COLUMNS
5. The applicant has provided documentation of rot on several columns, sinking columns due to rotting decking, and holes in the capitals due to animal damage. The rightmost two columns may be older elements, but the left columns were installed around 2004. The columns to be replaced are modest round columns with Tuscan capitals. Replacement columns will not result in the loss of historic material.

6. The proposed material is FRP (Fiber Reinforced Polymers), aka fiberglass. NPS Preservation Brief 16, "the Use of Substitute Materials on Historic Building Exteriors," [see attached] notes that FRP is produced as a thin rigid laminate shell formed by pouring a polyester or epoxy resin gelcoat into a mold. Reinforcing rods and struts can be added if necessary, and the gel coat can be pigmented or painted. Preservation Brief 16 notes several advantages to FRP substitutes, including "non-corrosive, rot-resistant," "easily installed," "integral color with exposed high quality pigmented gel-coat or takes paint well," and "high ratio of strength to weight." Disadvantages are listed as "combustible, fragile to impact," "high coefficient of expansion and contraction," and "vapor impermeability may require ventilation detail."

7. Similar column replacements were approved in ONK in 2012 and 2013, noting the "painted surface of a composite column is more difficult to discern from the painted surface of a new wood column," and that "new wood or new composite columns would be equally devoid of texture and 'new' in appearance." In February 2020 (2-B-20-HZ), an applicant at 1324 Grainger Avenue proposed a comparable fiberglass replacement column. This application did not include sufficient documentation of deterioration on the columns, so the Commission moved that the applicant explore further repair efforts, and if the columns were unable to be repaired, the fiberglass replacements would be approved. Finally, comparable replacements were approved at 1319 Grainger Ave in March 2021 (3-K-21-HZ).

8. The applicant has provided several possible manufacturers and measurements of the existing columns; final selection of the column replacements (along with capitals and bases) should be submitted to staff to ensure the new elements reflect the existing in size, design, surface texture, and finish.

STAIRS
9. The handrails and wood flooring covering the concrete stairs are not original to the house and removal is appropriate. The expansion of the steps' width will make the steps more proportionate to the overall façade width. The 13" thick cheek walls are modest in design, can be seen on comparable properties throughout the district, and will not detract from the house's overall integrity.