Recommended: Reinforcing porch elements and tying the porch roof, columns, and foundation together.

Not Recommended: Removing or closing in historic porches.

Two-story columns on a historic home in Alexandria, LA. Image Credit NPS Edward FitzGerald

Two-story columns on a historic home in Alexandria, LA. Image Credit NPS Edward FitzGerald

Porches are a common design element in the south and serve multiple functions. They provide shade and protect doors and windows from the elements. Historically, porches were used to escape the heat of an un-air conditioned house by providing both shade and air movement. Removing or closing in a porch is not recommended for historic buildings as this will change the historic character of the home.

During a wind or flooding event, porches can be a weak link that leads to damage. Porches may pull away from the building during these events, allowing wind and water to enter the building through unprotected openings or damaged areas. Porch elements that are not adequately attached can come loose and become wind-borne missiles.

It is important to understand how the porch roof is attached to the main building. Porch roofs are often either constructed as an extension of the main building roof or as a separate roof attached to the exterior wall. The failure of a porch and its roof can lead to water infiltration and damage to the building’s interior. Examining how a porch is connected to the primary structure can help identify weaknesses.

Note the galvanized metal straps tying this porch floor framing back to house sill plate. Image Credit NPS Sarah Marie Jackson

Note the galvanized metal straps tying this porch floor framing back to house sill plate. Image Credit NPS Sarah Marie Jackson

Reinforcing the porch will help ensure that all the elements of the building are tied together and working as a system. Hurricane straps or other fasteners should be securely installed, connecting roof rafters to ledgers and beams. The roof structure should also be securely fastened to the columns, and columns should be fastened to the porch floor or foundation. Anchor bolts can be used to connect the porch sill to the foundation. Care should be taken to ensure that any added reinforcing is not placed in visible locations that might disrupt the historic appearance of the home. If a porch is beyond repair or is not historically accurate, a new porch may be reconstructed using compatible materials that meet modern building code. Local design approval may be required if located in a historic district.

References

Disaster Mitigation for Historic Structures, 1000 Friends of Florida

Engineering Principles and Practices for Retrofitting Flood-Prone Residential Structures (Third Edition), FEMA

Additional Resources

Home Builders Guide to Coastal Construction: Technical Fact Sheet Series, FEMA

Homeowners Guide to Retrofitting: Six Ways to Protect Your Home from Flooding, FEMA


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National Center for Preservation Technology and Training
645 University Parkway
Natchitoches, LA 71457

Email: ncptt[at]nps.gov
Phone: (318) 356-7444
Fax: (318) 356-9119