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Indiana Historical Society, Jay Small Postcard Collection, Standard Cottage, 1886, Bethany Park, Indiana, Collection No. P0391, image © 2003.

PRESERVATION BRIEFS

Preserving Historic Wood Porches Aleca Sullivan and John Leeke

Evolution of the Porch

The History and Significance of a Porch

The Anatomy of a Porch

Assessing the Condition

Defining the Scope of Work

Undertaking the Work

Preservation and Maintenance

Repair

Replacement

Replacement Materials

Considerations for Contemporary Alterations

Safety and Building Codes

Summary and References

Reading List

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Few architectural features evoke more romantic notions or do more to define a building’s historic character than the American porch. The size, style, detailing, and location of a porch can tell volumes about the age and use of a building. Each component, from handrail or baluster to column or post, enhances the architectural character of the porch.

Alter or remove the porch and a historic building or streetscape can lose its visual integrity and historic authenticity (Figure 1).

Functionally, a porch protects an entrance from the weather.

Yet open porches are constantly exposed to sun, snow, rain, and foot traffic, and thus subject to deterioration, perhaps more than other parts of a building. Wood porches are particularly vulnerable.

Deferred maintenance and neglect account for the decay and loss of countless numbers of historic porches each year.

Deterioration from moisture and resultant wood rot, and

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ATTACHMENT NO. 9

Figure 1. Distinctive yet different, these front porches are important features along the street. The rhythm would be diminished if the front porch from one of the houses was dramatically altered or removed. Photo:

Aleca Sullivan.

Figure 2. Porches not only help define the architectural character of a building but also serve as living areas. They can be designed to take advantage of surrounding views. Cedar Grove, the home of the nineteenth-century landscape painter Thomas Cole, has an L-shaped veranda on the front and a two-story porch on the rear, providing an enviable view of the Catskill Mountains. Photo: Marilyn Kaplan.

damage caused by wood-eating insects are common problems that, when left unaddressed too long, can lead to the loss of significant historic fabric. Inappropriate repairs or insensitive alterations, such as the enclosure of a front porch, can be equally destructive and negatively affect the porch’s appearance. All these things can alter a building’s historic character. To preserve the character of the porch, as well as the historic building itself, it is essential to plan carefully before undertaking any work on a historic porch.

This Preservation Brief provides guidance for the everyday care of wood porches on older buildings. It focuses primarily on the maintenance and repair of wood porches, but acknowledges other, often challenging, work as well. This publication provides a brief history of the American porch and identifies its basic structural and decorative elements. It outlines how to assess the condition of a wood porch, how much work may be needed, and how to develop a specific scope of work. Detailed guidance on each level of work is provided, beginning with routine maintenance, followed by general repairs for various porch components, and concluding with replacement of parts that are beyond repair. Recommendations are provided for work that may require professional assistance. Although the Brief primarily addresses residential buildings, much of the information can be applied to wood porches on any structure.

Evolution of the Porch In colonial America, buildings in the northern colonies tended to echo British precedents with small gable-roofed extensions to protect main entrances. Whether open or enclosed, these extensions were called porches (from Medieval English and the French word porche, which stems from the Latin, porticus). Also known as porticos when supported by columns, these covered entrances were sometimes designed to respect classical order and details, especially on more stylish buildings.

Hooded doors or small covered entryways flanked by benches, often called stoops (from the Dutch stoep for step) that served as short covered transitions to and from the outdoors were common features, especially in New York and the mid- Atlantic colonies.

During the late 1700s and early 1800s as longer shed-roofed porches became more common, they were typically called piazzas, as they were then called in England. This term, still popular in some areas of North America, is adapted from the Italian word for open space or plaza. An alternate term for a long open porch, veranda, reflects British colonial design influence from the Indian sub-continent.

In French colonial areas, such as the Louisiana Territory, houses were often built with broad roofs extending well beyond the exterior walls to form surrounding porches, known as galleries. Porches were also important features of Spanish colonial buildings. In California, for example, many adobe ranches featured a portal with the roof supported by wooden posts.

African and Caribbean influences can also be found in North American porch traditions.

By the late eighteenth and early nineteenth centuries, porches became more common in larger, wealthier areas such as Philadelphia, Boston and Charleston. In both the North and the South, formal colonnades with tall columns dressed in classical orders were sometimes added to help dignify public buildings, hotels, and mansions. This trend continued through the 1830s and 1840s, as the Greek Revival became the dominant architectural style in many areas of North America.

The social role of porches as a transition space between indoors and outdoors and as a link between private and public realms evolved during the 1800s. By offering grand entrances and sheltered landings with views of the surroundings, Page 2 of 20Preservation Brief 45: Preserving Historic Wood Porches

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Figure 3. Throughout the late nineteenth and early twentieth centuries, millwork catalogues offered a wide variety of designs for porch parts, including columns, newels, balusters, spindles and brackets. As extolled in the Cedar Rapid Sash & Door Company's Standards Design Book, stock parts made embellishments to porches affordable both for new construction and "updating" existing homes. Courtesy of Charles Fisher.

prominent porches became expected features of inns, hotels and resort spas, where they could serve as promenades, social gathering spots, and refuges for more private retreats. Porches were also added to private homes to serve many of these same functions (Figure 2). As the country began to thrive and expand, porches became more than just covered entrances or ceremonial features; they became an integral part of domestic social life.

Some of the most significant factors that aided this shift were America’s industrialization and later suburbanization. As improvements to mass production methods helped spur industrial growth, many Americans had more money to spend and more leisure time. Meanwhile a growing middle class was moving to new suburban neighborhoods. Inspired by the pattern books of Andrew Downing and George Woodward and the published designs of such architects as Alexander Jackson Davis and Calvert Vaux, the homes of these mid-1800s suburban neighborhoods were typically ornamented by elaborate porches dressed with fancy millwork. By this time, millwork catalogues and builders’ pattern books offered a wide variety of designs for porch parts. With mass production, these fancy brackets and other ornamentation became less expensive, making it easier and more affordable to construct decorative porches (Figure 3). With mechanized wood turning lathes, the cost of posts, balusters and decorative spindle work also decreased to a level affordable by many. Adding a porch with wood ornamentation could enhance even the smallest and simplest of houses. Even older homes could be modernized with a fancy porch addition, stylized to the latest fashion trends.

Such changes culminated in the large, highly decorated wrap-around porches of the Queen Anne style.

The second half of the nineteenth century was the golden era of porches. The social role of the porch increased as it evolved into an outdoor parlor, a true extension of the house into the landscape. Often partially screened by shrubs, porches could provide occupants with discreet opportunities for social contacts that might otherwise be difficult to achieve in an age obsessed with manners and proprieties. For many, sitting on the porch became an important part of their daily routine. Perhaps President Rutherford B. Hayes best summed up the love that Victorian-era Americans felt towards their porches when he recorded in his journal in 1873: “The best part of the present house is the veranda. But I would enlarge it. I want a veranda with a house attached.”

By the early twentieth century, the hygiene movement, which stressed that access to fresh air could help prevent or remedy such diseases as tuberculosis, contributed to the development and proliferation of the sleeping porch. These porches were usually located on the second floor next to bedrooms. This era also saw the rise in use of insect screening on porches to guard against the discomfort of mosquitoes and the diseases they spread, such as yellow fever and malaria.

While innovations fostered the proliferation of porches in the nineteenth century, new inventions helped lead to its decline in the twentieth. As the automobile boom of the early twentieth century made it easier for people to get out of the house for entertainment and relaxation, porches began to lose popularity, especially as architectural styles and social attitudes changed. With the telephone, neighbors and friends could chat without personally meeting. And housing styles popularized in the construction boom after World War II often omitted front porches all together as backyard patios became the focus of private outdoor activities. Finally in the mid-twentieth century the broad availability of air conditioning and television enticed many people to stay inside at night and brought the golden era of the American porch to an end.

Understanding the History and Significance of a Porch In preserving historic buildings, it is important to understand the history and evolution of a particular structure and what features contribute to its historic character. This is especially applicable when working with historic porches since they usually are prominent features, significant to the character of a building.

Answers to the following questions will help establish the significance of a porch.

What has the porch looked like in the past?

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Figure 4. Celebrating the 4th of July in 1912, this gathering of family and friends reflects the popularity of the porch as a social gathering place. While not overly ornate, each detail of the porch from the roof balustrade to the turned columns to the simple lattice work facing the deck contributes to its character, creating in effect the dominant architectural feature of the building. Photo: © Utah State Historical Society

a. Pier, penetrates ground, supports floor structural system and columns

b. Fascia covering floor framing

c. Floor (or deck)

d. Bed Molding covering joint between fascia and floor

e. Column supporting entablature above

Early photographs, insurance maps, or tax records can provide useful information. These may be found at city or county offices, historical societies, libraries or even from former owners or neighbors. Such documents may indicate the footprint of the building or show long-lost details of the building’s appearance. Physical evidence of historic porch footings may exist. Paint shadows of a former roofline or moldings can provide clues about details now missing. Old porch parts may have been “stored” under the deck during past repairs.

What, if any, changes have taken place to the historic porch over the years?

On many porches elements such as columns, balusters, and finish details correspond with the design and detailing on the rest of the house. With other porches, the style of these features may differ from the rest of the building, but may reflect an important chapter in its history. Sometimes, parts of porches may have been lost due to neglect or remodeling.

Questions about what historic fabric remains, what has been altered over time, and whether earlier changes are now an integral part of the historic character should be resolved before planning major porch work. Determining the historical evolution of the house may require both physical and archival research and in some cases the professional eye of an architectural historian.

What are the character defining features of the porch?

The open qualities are one of the key features of most historic porches. Overall size, shape and design are obviously important components as well. There are numerous other contributing features which may exist, including the shape of the porch roof, the way a large porch is divided into distinct bays as with columns, the nature of the supporting foundation, the style and size of columns and balustrade, and whether the porch is raised or largely at grade. The simplicity of a porch or its richness in detail will also help define it. Materials are usually important as well, not just the wood features, but also whether other materials exist such as masonry columns and steps (Figure 4).

How does the porch contribute to the building’s overall appearance?

The size and location of a porch and how much of the historic features survive will help define its significance. A highly ornate porch across much of the front facade may be the most distinctive feature of the entire house, while a small simple porch on an otherwise plain cottage may be equally significant. The architectural style of a porch may relate to the building and may help define its character. Sometimes a later style porch may have been added to a building or may have replaced an earlier porch. In such cases, the later porch may have acquired importance in its own right. On the other hand, a later porch may be of such poor quality that it detracts from the building’s historic character. Because porches are so diverse in terms of style, size, shape and detail, their significance should be assessed on a case-by-case basis with an understanding of the overall importance and evolution of the building.

The Anatomy of a Porch

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Entablature (f, g, h)

f. Architrave of entablature

g. Frieze of entablature

h. Cornice of entablature

Roof Railing (i, j, k, l)

i. Newel (or Pedestal) of roof railing

j. Balusters of balustrade

k. Top rail of balustrade

l. Bottom rail of balustrade

Balustrade around floor (m, n, o)

m. Top rail of balustrade

n. Balusters of balustrade

o. Bottom rail of balustrade

Structural system of deck (p, q, r)

p. Girder rests on piers and ledgers, support joists

q. Ledger fastened to house sill, supports girder

r. Joist fastened to girder, supports floor

Roof Structural System (s, t, u)

s. Beams inside the entablature span from column to column, support plate

t. Plate of the entablature rests on beams, supports roof rafters and ceiling beams

u. Rafter of the roof structural system

Assessing the Condition Before undertaking most repairs, it is important to assess the condition of the porch. The assessment is greatly facilitated if the porch has been regularly maintained and a record of past work is available. In most cases, however, a condition survey must rely almost exclusively on the physical examination of the porch, documenting the findings with notes, photographs or sketches.

Many older porches were constructed using good construction practices and materials. As a result, porches that are over 100 years old are not uncommon. Most porch deterioration can be attributed to the lack of proper maintenance. Important questions to address in assessing the condition of the porch include the following:

How is the porch constructed?

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Figure 5. Even historic porches that appear to be in total disrepair may be repairable. While the roof needed replacement, much of this porch was repaired, including such features as the decorative columns, ornamental brackets, and balustrade. Photos: John Leeke.

Figure 6. A traditional way to extend the life of porch posts was to place posts on metal feet, thereby

A porch is rarely an independent, unattached structure. It may, however, have its own foundation, attached to the house only along the deck and the roof. Alternatively, it may be an included or engaged porch that is integrated with the actual structure of the house. The relationship between the porch and the house is important. If the outer support posts are decayed or if foundation piers are sinking, the roof structure may be pulling away from the house. Many porch decks are fastened to the main building on a ledger, a horizontal board along the house’s foundation. A decaying ledger may compromise the structural integrity of the porch and can represent a major safety issue.

Are the foundation and structural members of the deck sound and providing adequate support for the deck, posts and roof above?

The porch structure needs to be sound at every level. Therefore, a visual inspection of the underside of the porch is necessary to determine its condition. Major cracks in structural members, failed joints, significant wood rot, or evidence of widespread insect infestations (termites, carpenter ants or powder post beetles, for example) are usually signs of serious structural damage. Such conditions may require consultation with a professional architect, engineer or building contractor familiar with old buildings. For an adequate assessment, it may be necessary to remove facing boards to check for potential decay in the structural sill behind (Figure 5).

What is the condition of the porch?

Porch foundations may be a continuous wall of masonry, a series of masonry or wood piers or metal pipes, or a combination of these. Missing sections of the foundation, crumbling masonry mortar joints, or areas where the sill or joists no longer fully rests on the foundation may represent serious deficiencies. What appear to be deep foundation footings may only be stones or cement blocks sitting on top of the ground. The footings must be stable enough to adequately support the porch in its current or intended use. The smell of mold or appearance of fungal growth on wood beneath the porch is an indication of deficient air circulation and that conditions exist for wood decay. Recent changes that can contribute to deterioration should be identified for correction, such as a clothes dryer vent dumping warm moist air underneath the deck. The enclosure of original air vents in crawl spaces or the boarding up of latticework between piers are other changes that will usually promote an unwanted moist environment.

Are the porch posts providing adequate support?

Posts, pillars or columns usually help support the porch roof or an upper deck.

Establishing what the posts are made of and how they are constructed will aid in understanding how they function and may deteriorate over time (Figure 6).

Although the posts on a wood porch are commonly made of wood, they may be of masonry or metal or a combination of materials. Large round columns usually are made of wood staves similar to the way barrels are constructed;

smaller diameter columns may be solid. A sag in the deck below or a faltering foundation can impact the supporting role of a column or post above. Wood columns and posts are prone to water seeping into open joints, particularly in the base and the lower end of the shaft. It is not uncommon to find that older columns have had patches and replacement bases.

Is the roofing and drainage system keeping the water away from the porch?

Porches were designed to shed water. This means water will move away both from the building and the porch and not pond and saturate the wood.

Continuously high moisture levels promote fungal growth that eventually causes wood to decay. Peeling paint on ceiling boards in a specific location is a sign of a possible roof leak. Clogged or missing downspouts and gutters can cause erosion at the foundation and can contribute to reverse-grade draining

Page 6 of 20Preservation Brief 45: Preserving Historic Wood Porches providing a separation between the wood post and wood deck. This helped to prevent the wood post from rotting at the base. Early post feet were simple iron bars bent unto a stirrup shape. By the late nineteenth century manufactured cast-iron feet were common, consisting of a pair of disks separated by a short pipe. Post feet are still available today. Courtesy of Old-House Journal/Brian McNeil.

Figure 7. Common problems with porches that can contribute to serious wood decay include cracks in woodwork and joints that have opened up. Both provide an easy path for water seepage. Trapped moisture can foster peeling paint, wood decay and insect infestation.

Open joints and cracks should be checked for evidence of more serious decay and marked for caulking or repair.

Photo: John Leeke.

that is directing water under the porch instead of into the yard. Inadequately sloped porch floors can result in improper drainage and promote deterioration as exhibited, for example, by cupping floorboards.

What is the flooring condition?

The porch component most subject to decay is the flooring. Often decay starts at the exposed ends of the boards or where cracks, checks or open joints have occurred and are exposed to the weather. Flooring should be checked frequently for peeling paint, rotted wood, and for loose, cupping or splintery boards. Where water is ponding, there is insufficient slope away from the building, a condition that should be corrected. Floor deterioration can also start in unlikely places such as the result of frequent hose washing to remove dirt or the placement of plant stands directly on the floor without proper moisture barriers. Firewood stored on a porch may trap moisture on the floor and harbor active insect infestation that can be ruinous to a wood porch.

Thick floor mats and carpeting also may trap moisture, leading to premature decay.

Is there evidence of general wood decay?

Wood deterioration may take different forms such as fungal decay, insect infestation or even sunlight degradation of exposed unfinished wood. Decay may be present where two wood surfaces meet and are not adequately protected from water, such as along open joints or behind moldings. Dark streaks, discoloration, and widespread peeling paint on a finished ceiling suggest excessive moisture or water leakage. It may be necessary to remove several finished boards to properly identify the cause of the problem and to insure damage has not extended to structural members behind. Trails of carpenter ants are another sign of potential decay since they will infest moist decaying wood. Where inadequate painting has left wood exposed for a long time, damage to the wood surface from light itself will occur, typically indicated by wood discoloration. Without sanding or scraping back to a sound wood surface, repainting will result in premature failure of the paint film.

Are there open cracks or joints in the woodwork?

Tightly sealed connections keep water out. Where individual boards come together, cracks in woodwork and joints can eventually become a major problem (Figure 7). Cracks are primarily caused by movement and water penetration. Movement of structural members beneath the finished woodwork can shift the position of individual boards and trim, breaking open the thin coating of paint over joints. This condition is common on porches with shallow foundations that are subject either to annual winter frost heaving or where soil conditions undergo major seasonal changes in moisture content. Changes in the moisture content of the wood itself due to repeated wetting and drying or changes in seasonal humidity can also cause noticeable expansion and shrinkage across the width of a board. This provides opportunities for water to penetrate unprotected areas.

Does peeling paint indicate deeper problems?

An unbroken layer of paint covering all wood surfaces is the first line of defense against moisture causing decay. Over time, even hairline paint cracks can allow water to penetrate, causing paint to peel down to bare wood. Such peeling occurs near breaks in the film, at opened joints, or where the paint has been scratched or scraped. Peeling can also occur over large areas where there is high moisture and insufficient ventilation. Areas of particular concern include the crawl space beneath the porch deck, inside columns that lack ventilation, and in a roof structure that has a finished ceiling and lacks ventilation. If heavy paint build-up exists on columns, floors and trim, moisture can be trapped within the wood, resulting in the loss of paint adhesions and eventual wood decay.

Are trees, shrubbery and flowerbeds threatening the porch?

Shade trees can make the porch a cool oasis, but the branches of a nearby tree rubbing on the roof, gutters or wood trim often will cause damage. Tree roots may destabilize porch foundations or supports. Bushes growing against the porch and not trimmed back on a regular basis may block wood porch components from drying breezes, thereby letting moisture build up in the woodwork. Flowerbeds and mulch around the porch that are not properly sloped downward in a grade away from the house will promote moisture problems.

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Defining the Scope of Work Once the historical and physical assessments are complete, it is important to define the scope of work. How much and what kind of work will need to be done to make the porch structurally sound while preserving its historic character, or to recover its historic appearance if portions are extensively deteriorated, altered or missing? Any part of the porch that defines its historic character should be repaired or replaced to match. Since the porch may display varied levels of deterioration, the spectrum of work in one project can include maintenance, repair, and replacement. When laying out the scope of work for the project, each individual component and decorative element of the porch should be identified, and linked with the work needed for that item.

Undertaking the Work The highlighted work approaches in this section are based on The Secretary of the Interior’s Standards for the Treatment of Historic Properties and the Accompanying Guidelines for Rehabilitating Historic Buildings. The Standards and Guidelines provide a sound philosophical and practical framework for achieving the highest retention of historic materials and character possible. Thus, the familiar hierarchy is applied: maintain, repair, and then replace only if necessary.

Contemporary alterations are discussed in a separate section.

Preservation and Maintenance There are a variety of tasks that can be done on a regular basis to extend the life of a porch. In addition, a visual inspection of the porch should be made every spring and fall to determine if more in-depth repairs are necessary. Fortunately, ongoing maintenance significantly reduces both the need and cost for later repair work and represents good preservation practice.

When properly maintained, a well-constructed porch can last for decades.

Routine Cleaning and Other Surface Work Since many porches are essentially another living space, extending housekeeping to this space makes practical sense.

Regular maintenance includes sweeping the wood porch decking, and, if needed, an occasional damp mopping. Removing dirt and leaves by sweeping is preferable to frequent hosing off the deck with water. The latter can saturate the woodwork, thereby promoting decay. Frequent sweeping will reduce the accumulation of abrasive materials, such as dirt and sand.

While visually pleasing to some, vines and plants should be kept trimmed away and not be trained to grow onto or allowed to grow beneath porches. Plants and vines unfortunately reduce ventilation, promote a moist environment for insects and decay, accelerate open wood joints and impede cyclical maintenance. As an alternative, traditional freestanding trellises can be used to support plant growth away from the porch.

There are certain precautions that are recommended for wood floors. Rubber mats, rugs or indoor/outdoor carpeting can trap moisture and condensation on their underneath side and should not be used on a wooden porch floor. Keeping flower pots up off the wooden deck will help prevent moisture buildup and decayed spots – wood, clay or metal “trivets” that hold the pots an inch or more off the wooden deck are helpful, but the pots should be moved to different locations periodically.

In colder climates, light snow can be swept off the porch. Snow shovels with a hard rubber leading edge or plastic shovels cause less damage to wood than metal, while paint in good condition helps ice to release more easily. Sand or clean kitty litter can be sprinkled on ice to prevent slipping; however, they should be later swept off the porch, as they are abrasive.

Salt (sodium chloride) is not recommended for ice removal on older porches as it can promote corrosion and failure of nails and other fasteners. Magnesium chloride is an alternate de-icing salt that is less corrosive and less damaging to masonry and plants. If any de-icing salt is used, be sure to scrub and rinse off the porch deck in the spring. Boot scrapers and brush-mats at the bottom of the stairs are recommended for muddy areas.

Painting Spot painting and resealing of open joints should be undertaken at least every other year (Figure 8). Heavily used stair treads may require more frequent paint touchup. When peeling paint or bare wood is evident, inspect to ensure it is not signaling deeper problems, such as decay. With sound wood, scrape off the loose paint, sand, prime, and repaint the area. Where lead paint is present, appropriate lead hazard precautions and procedures apply. Only top-quality exterior primers and paints are recommended, selecting for the deck and stairs specially formulated paints. Where wood porch steps are exposed to moisture, grit added to the wet paint during application will help improve safety.

Repair

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Figure 8. Decay can start when wood is left exposed to the weather or where joints open up. An inexpensive way to extend the life of the existing porch paint without jeopardizing the historic material is spot paint and caulk where needed every year or two. This cost-effective procedure is particularly effective in maintaining wood porches where the exposure to weathering is high.

Photo: John Leeke.

Figure 9. The ends of porch roof rafters are often susceptible to moisture decay. When concealed by a soffit or ceiling, rafters can be repaired by adding new sister boards. Where roof rafter ends are exposed, splicing new wood onto the old (dutchman repair) and use of epoxy consolidants and fillers both preserve sound historic fabric while retaining the historic appearance. Photo: Paul Marlowe, Marlowe Restorations.

Many repairs may be successfully undertaken by property owners, while major projects often require the special knowledge and equipment of an experienced contractor. Repairs generally include patching and reinforcement of historic materials. The roof and foundation are particularly important to the preservation and the structure of a historic porch yet they often receive much less attention than ornamental features. Their neglect will usually lead to more costly work. Repairs to features such as a balustrade or flooring can encompass limited replacement in kind when the porch part is severely deteriorated or when a part of a repeated feature is missing altogether. Some common porch repairs are discussed in this section.

Filling Open Cracks or Joints To seal open cracks or joints, start by scraping off the paint back a few inches from the opening and removing old caulk to expose bare wood. The opening should be examined for any signs of wood decay, and to determine if the joint is loose due to a loss of connection, such as rusted nails. After correcting any problems, apply a water-repellant wood preservative that can be painted. Such preservatives are either an oil-based or waterborne solution of oils or waxes with mildewcide, fungicide and pesticide added.

Then apply a high quality exterior wood primer to the wood surfaces where a sealant or caulk is to be used. Most open cracks or joints then can be filled with a sealant or caulk, while larger ones may need the addition of a backer rod. In some cases, small metal flashing over the crack or open joint may be more effective and longer lasting but, when used, care should be taken with proper installation. The final step is painting.

Patching with a Dutchman Repair This traditional technique is often used to repair localized cases of decayed wood and, when undertaken with skill and care, will serve as a permanent repair (Figure 9). If the damaged area has a structural function, temporary bracing or other support will be necessary. Otherwise the first step after removing any paint around the damaged area is to chisel or mechanically remove the decayed wood. It is best to use the same type of wood being replaced and the new or recycled wood should be seasoned to avoid shrinkage. The repair procedure involves cutting a piece of wood, called a dutchman, slightly larger than the area of damage that has been cut out. The dutchman then is laid over the damaged area and an outline scribed into the original wood surface below. Next, a chisel or router is used to follow the scribed line to form an opening in the existing wood for the new piece.

As a preventive measure, an appropriate fungicide should be applied to the surrounding old wood and allowed to dry. The dutchman is then glued into place with waterproof adhesive, such as an epoxy formulated for wood. The repair is finished by trimming or sanding the surface of the new wood down flush with the surrounding existing surfaces, priming and painting.

Patching with Epoxy or Wood Fillers There are a variety of commercial wood fillers. Cellulose based fillers consist of wood fiber and a binder and have been available in stores for many years. Only those suitable for exterior applications should be used and they will require a protective finish. Epoxies are a more contemporary product, commonly used by experienced contractors and woodworkers.

Epoxies are petroleum-based resins created by mixing two components in accurate proportions that result in a chemical reaction. The result is durable, moisture-resistant consolidants and fillers that bonds tenaciously with wood, and can be sawn, nailed or sanded. Epoxies are for use only in areas that will be painted, as they do not take stain and deteriorate under sunlight. Since epoxies are more difficult to work with than other wood fillers, experience working with epoxies is needed for successful repairs.

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Figure 10. This nineteenth century porch column is made of wood staves, similar to the way a wood barrel is put together. After replacing the torus and making dutchman repairs to the apophyge along the base, the

Repairing Railings and Balustrades Balustrades and railings are not only practical and safety features, they typically are highly visible decorative elements.

Unfortunately, balustrades and balusters are frequently altered, covered, removed or completely replaced even though in most cases they can be repaired in a cost-effective manner. To preserve historic fabric, the repair of old balustrades and railings is always the preferred approach. A broken baluster usually is one in need of repair, not replacement.

Loose railings and balustrades present unsafe conditions and need to be repaired as soon as possible. Start by examining the points of attachment to determine exactly why the railing or balustrade is loose. Common reasons include rusted fasteners, decayed wood, or physical stress that has broken the fasteners or split the wood. Paint and decayed wood must be removed. Where fasteners are broken yet the wood is sound, the balustrade can be re-fastened using hot-dipped galvanized or stainless steel nails or screws, setting the heads of the fasteners below the surface of the wood and using a wood filler to cover and seal. Next repair deteriorated wood by using a dutchman or wood-epoxy repair. The repaired joints then can be sealed and painted.

Replacing Missing Balusters The balusters help comprise a wood balustrade and come in three general styles: simple rectangular shape; flat, pattern-sawn (usually a board with some decorative edge or cutout); and turned. It may be necessary to replace certain balusters that are beyond repair or missing altogether. Some are easy to replace with new matching balusters while others can be more challenging in terms of both design and costs. Finding or affording replacement balusters may take time since they should match the historic baluster as closely as possible. In the meantime, unsafe balustrades can be temporarily stabilized, introducing temporary new material that soon will be replaced.

In replacing individual balusters, simple, rectangular balusters should not be replaced with pattern-sawn or turned ones unless physical or pictorial evidence survives which indicate they previously existed historically on that particular porch.

Such an alteration can change the historic appearance of the porch or be incompatible with the character of the building.

Determine the size and shape of the missing balusters either by examining adjacent ones or temporarily removing an existing baluster as a sample. Heavy paint buildup should be removed so that the original dimension can be established.

Scrape and clean the joint locations and make repairs to any deteriorated areas. A new baluster is then fabricated to match the original in design and material, either on site or by taking a drawing or sample to a local woodworking shop. The new baluster should be made one-half inch longer than needed on both ends. Measurements are taken from the bottom surface of the top rail to top surface of the bottom rail. Joints on the new baluster can be laid out with a pencil, using a sliding bevel to transfer any angles, and the new baluster trimmed to fit with a handsaw. After test fitting, the ends and any exposed end-grain of the baluster need to be sealed with a high-grade primer or epoxy. Next, apply a paintable water-repellant coating to all exposed wood surfaces, and apply a primer. The baluster can then be fastened in place with hot-dipped galvanized or stainless steel nails, and the nails set. Finally, seal joints and fastener holes and paint the baluster.

Repairing Column Plinths and Bases Columns not only enrich the historic character of the porch, they provide support for the roof structure above. Because of their detail and complex construction they can be costly to repair or replace, making maintenance and minor repairs important. Column plinths and bases tend to deteriorate because of their exposed location on the outer edge of a porch (Figure 10). Leaking gutters can result in water draining into the entablature and down into hollow columns, while clogged or capped gutters can allow water to pour down and splash back onto the column bases. Open joints and limited wood decay can be repaired using methods previously discussed. Column repairs usually are undertaken by an experienced carpenter, since it may involve structural support of the roof above.

Repairing Floorboards and Ceiling Boards Floors should slope down toward the outer porch edge for proper drainage. If drainage is inadequate, moisture buildup will cause deterioration of the floorboards.

Flooring can also deteriorate due to movement in the supporting structure below. If a floorboard is soft or broken, the extent of decayed or split wood can be determined by probing gently with an awl. The existing floorboard can then be removed, cutting the length if needed so that the end will center on the next nearest joist or girder. Once the board has been removed, the structural framing beneath should be examined for deterioration and to ensure it is sound. A new floorboard is then cut to length, and the outer edge shaped to match the adjacent boards. After priming the replacement board, nail it in place and repaint.

Page 10 of 20Preservation Brief 45: Preserving Historic Wood Porches column and pedestal are ready to be reinstalled on the porch. Photos: NPS files.If a section of the ceiling is deteriorating, it is likely that there is a roof or gutter problem. To determine the cause of deterioration, inspect the ceiling, gutters and roof, including the internal roof structure. After making necessary repairs, the ceiling boards can be repaired in much the same manner as a deteriorated floorboard.

Repairing the Porch Roof and Gutters With roof leaks, the entire porch is at risk. Leaks can promote decay in roof rafters, ceiling joists, and columns as well as in areas more easily to detect such as the ceiling and fascia. Inspect the roof covering, gutters and flashing for deterioration and improper performance. They can then be repaired or replaced, as needed, to keep water out of the structure. Avoid having the gutters and downspouts on the main roof drain onto a porch roof.

Repairing the Foundation Unstable foundation supports can cause serious damage to a historic porch. There are numerous causes and solutions. If the posts supporting the porch deck rest on stones or brick set directly on the ground, there can be seasonal shifts due to the changing moisture content of the soil or freeze/thaw conditions that will require regular attention. Under certain conditions, it may be advisable to extend footings for the posts below the frost line. Where moisture problems exist, improved drainage may be necessary. It is not uncommon to find that masonry joints in the foundation wall or piers have deteriorated as a result of rising damp, where moisture from the soil percolates up through mortar joints. This condition may lead to the eventual breakdown of the mortar and even old brick and soft stone. In such cases, it will be necessary to replace the areas of damaged masonry and repoint the mortar joints.

With wooden posts, insect damage or rot may necessitate corrective measures to strengthen the foundation. Techniques can include one or more of the following: epoxy consolidation; dutchman repair; or the addition of supplemental supports to the foundation posts and joists. In some cases damage may be extensive enough that the only real solution is rebuilding the foundation.

Repairing a Porch Apron The apron, skirt, or latticework is a highly visible and functional porch feature. An apron keeps animals out from under the porch, while at the same time allowing air to circulate, preventing unwanted moisture buildup. Aprons typically are made up of a wood frame, surrounding either a simple lattice or a repetitive pattern of decorative sawn boards. Because the frame is so close to the ground, decay is common. Other causes of decay include plantings around the house that are growing too close to the latticework and improper water drainage. An apron may require partial or complete disassembly for proper repair. One or more of the apron frames should either be hinged or secured with turn buttons for easy access to under a porch for inspection and maintenance.

Replacement When individual porch parts are deteriorated beyond the point of repair or missing altogether, replacement is necessary. To retain the historic character of the porch, the replacement parts should match the historic component as closely as possible in material, design, color, texture, and other qualities. To achieve this, existing evidence of the historic design, such as a baluster or column detail, or a tongue and groove floor design, should serve as a pattern for the replacement part. When replacing an element, it may provide a good opportunity to upgrade the wood to another species that is more decay resistant, or to one with a vertical grain that is more resistant to cupping or splintering. In limited cases, it may be appropriate to use a substitute material for the replacement material as long as it conveys a close visual match. Before replacing a deteriorated historic porch component, it is important to understand how it was constructed and installed, and what lead to its deterioration. If the replacement part does not sufficiently match the historic part, the character of the porch may be diminished, or even lost. If the cause of material failure is not addressed, the replacement will also fail.

Replacing Porch Floorboards If a large section of the porch floorboards is deteriorated, the framing beneath may also be damaged and should be assessed. Replacing floorboards can often expand into repairing the structural sills, girders, and joists beneath. Complete floor replacement will likely require the removal of floorboards that are under structural posts or columns. This may necessitate the careful stabilizing in place or the removal of the posts or columns and the installation of temporary support for the roof structure. If the floor failure was caused by inferior wood, the wood quality can be improved at this time.

However, the new wood flooring should match the existing in thickness, width, shape and texture. The slope of the floor should be maintained, or a slope may need to be created if none exists. A slope of ¼ inch per foot or greater, away from the house, is needed for adequate drainage. Boards are usually laid in the direction of the slope, sloping down to the outer edge of the floor.

Replacing Steps

Page 11 of 20Preservation Brief 45: Preserving Historic Wood Porches

Figure 11. The lower shaft of the porch columns had decayed as water wicked up through the end grain (top).

The column shafts were repaired in place by cutting out the deteriorated wood and making repairs using epoxy consolidants and fillers. (bottom). The column bases were replaced. Photos: Paul Marlowe, Marlowe Restorations.

Porch stairs receive heavy usage and are close to the ground, making them predictable candidates for deterioration. Stairs should be repaired or, if necessary, replaced by an experienced carpenter who understands the safety codes and is experienced in fabricating custom stair parts to match original detailing without depending only on store-bought parts.

Replacing Column Plinths and Bases or Entire Columns When plinths and bases are deteriorated beyond repair, they can be replaced without replacing the column shaft, which may still be in good condition or require only minor repairs at the bottom. Such replacement will involve temporary shoring for the roof. One-story columns and shafts are often more easily removed during this work, while taller columns are sometimes supported in place. If only a few plinths or bases are deteriorated, it is often economical to have new ones made of wood to match. If numerous plinths and bases are deteriorated, replacing with bases made of rot-resistant materials can make economic sense; however, care must be taken to ensure that all the visual qualities including design, size, shape, color and texture of the historic part are matched (Figure 11).

Entire columns may need to be replaced, but an owner should first consider all repair alternatives. Some contractors routinely recommend complete replacement of one or all columns due to the challenge of a clean repair (particularly with stave-built columns), or because they see the potential for more profit in complete replacement. If a contractor recommends complete replacement, other opinions should be sought to ensure repair is truly not feasible. Preserving the historic appearance of old columns is not the same as preserving historic columns.

Where a replacement turned or staved column is needed, a local millwork may be able to match the profile or pattern.

Alternatively, the Internet is helpful in identifying potential sources of replacement columns that can match the appearance of the remaining ones.

Wood Characteristics

Species Cut or Grade Cost Workability Resistance to

Decay

Resistance to

Cupping

Paint Holding

Ability

Redwood Clear, Vertical-grain, all-heart

$$$ Fair Excellent Excellent Excellent

“B” Select, flat-grain $$ Fair Excellent Good Good

Cedar Clear $$ Fair Excellent Good Fair

Cypress Clear $$ Fair Excellent Fair Good

Douglas Fir “C” & better, Vertical grain

$$ Fair to Poor Good to Fair Excellent Fair

Southern Yellow

Pine

“D” Select, flat-grain $ Fair Fair Good Fair

Vertical-grain $$$ Fair Fair Excellent Fair to Good

Eastern White

Pine

“D” Select, flat-grain $ Excellent Fair Excellent Good

Vertical-grain $$$ Excellent Fair Good Excellent

Poplar Firsts and Seconds $ Good Poor Good Fair

Clear $$$ Excellent Excellent Excellent Good

Page 12 of 20Preservation Brief 45: Preserving Historic Wood Porches

American

Mahogany

This table summarizes the characteristics of just a few of the different species available, including the workability…