Porch Construction near you

Naming the type early keeps a quote honest, because the roof and the connection to the house are what separate them, not the floor.

A porch is a walking surface above grade with stairs, so the guard and stair rules apply. The figures below come from the residential code as adopted and published by Seattle, which reprints the model text; confirm the edition adopted where you live.

The National Park Service's assessment of historic porches is the best short account of porch failure available, and every point in it applies to a new porch too. It identifies flooring as the component most subject to decay, notes that decay often starts at the exposed ends of boards or where cracks, checks or open joints have opened to the weather, and states directly that where water is ponding there is insufficient slope away from the building, a condition that should be corrected. Inadequately sloped porch floors, it says, result in improper drainage and promote deterioration, visible for example as cupping floorboards.

Ventilation under the deck is the second half. The brief warns that the smell of mold or the appearance of fungal growth on wood beneath the porch indicates deficient air circulation and that conditions exist for wood decay, and names two changes that usually promote an unwanted moist environment: enclosing original crawl space air vents and boarding up latticework between piers. It also flags a clothes dryer vent dumping warm moist air underneath the deck as a cause worth correcting. Latticework at the perimeter is not decoration; it is the ventilation.

The connection to the house is the third. Many porch decks are fastened to the main building on a ledger, a horizontal board along the house's foundation, and the Park Service states that a decaying ledger may compromise the structural integrity of the porch and can represent a major safety issue. It also notes that if the outer support posts are decayed or foundation piers are sinking, the roof structure may be pulling away from the house. On a new porch, that means the ledger flashing and the footing depth are the two details worth the most scrutiny.

A large share of porch work in the United States happens on houses old enough to be in a local historic district or listed on a register, and that changes the approval path and sometimes the design. The Park Service frames the work around the Secretary of the Interior's Standards for the Treatment of Historic Properties, applying the familiar hierarchy: maintain, repair, and then replace only if necessary.

That hierarchy has practical consequences when a homeowner wants a new porch. Where an original porch survives in part, a historic district commission will generally expect the surviving material to be retained and repaired rather than torn off and rebuilt in composite. Where the porch is long gone, the question becomes evidence: photographs, ghost lines on the siding, remaining post bases, and the pattern used on comparable houses on the same street. A rebuild designed from evidence tends to be approved; one designed from a catalog often is not.

Enclosure is the other flashpoint. The Park Service states that much of the character of a historic open porch is its openness, that in most cases a historic open porch should not be enclosed, and that it is almost never appropriate to enclose a front porch on a historic building to create interior space, while a less prominent porch on a less visible elevation may have less impact. It also notes that screened porches have been popular since the arrival of inexpensive durable wire insect screening in the late 1800s, and recommends following that historic precedent by setting screened panels in slender, easily repaired frames behind the railings and columns.

Almost all of what the Park Service recommends for a hundred-year-old porch applies to a brand new one, and the first decade is when the habits get set. It advises a visual inspection of the porch every spring and fall to determine whether more in-depth repairs are necessary, and observes that ongoing maintenance significantly reduces both the need and cost for later repair work and that, when properly maintained, a well-constructed porch can last for decades.

The roof is the dividing line. An uncovered platform at the door and a roofed porch of the same size are different jobs, because the roof brings footings sized for concentrated loads, beams, a tie-in to the existing roof, flashing, a finished ceiling and often gutters. After that the main variables are the height above grade, which decides whether guards and how many steps are needed, the frost depth and soil at your address, the complexity of the roof geometry, the column and railing detail, and whether the work is in a historic district where materials and profiles may be specified for you.

Put the project on LokalMatch with your ZIP code, the width of the elevation, the height above grade, whether you want it roofed or screened, and whether the house is in a historic district. Porch and carpentry contractors in your area receive the request and the interested ones reach out. Those contractors pay for the requests; homeowners use LokalMatch free. LokalMatch does not build porches, does not quote and does not screen, rank or recommend anyone who contacts you, so verifying the license, the insurance and the flashing details is on you.