Want to add a roof over your existing deck?

Roof over raised deck

We recently participated at the local Home and garden Show in Oaks, PA. And as with many other Home Shows across the country, one of the most popular planned projects this year from attendees at the show was to add a sunroom, roof, or screened porch on a new deck, or to their existing deck. In the case of an existing deck, the question is can that be done? The answer to this question is usually yes, with qualifications. Whenever a roofed structure of any type is added to an existing deck there are several issues that, if neglected, could create future problems. The first important issue relates to the building code requirements for a roof. In all cities and counties in this area roofs require a building permit, even when added on top of an already existing deck. This permit is required regardless of whether the structure will have screens, windows, or even if it is going to be open. It is a mistake to assume that because the deck is existing, the roof is automatically legal at the same size. Some homes have existing decks that were built without permits and are too large or too near the property line to roof the deck without changing the design of the existing deck to meet current codes and setback requirements. In addition, some cities have different setback requirements for roofed structures than for decks.
The second important issue has to do with the deck strength and its original build quality and design. A great many decks have been built that only adequately hold up as decks, without the additional weight of a roof structure, walls, or windows. In some cases additional bracing, columns or beams need to be added to the existing deck structure to support the added weight of the proposed roof. In other cases it may be less expensive to tear down the deck than to repair it enough so that it can permanently support the new roofed room or porch. When a roof or wall weight is added to a structure not designed and constructed to support it, it can sag, pull away from the house, leak, and or create danger of future collapse. We at Archadeck have been called out to examine many sunrooms and porches built on poorly constructed older decks that have caused multiple expensive problems for the homeowners. The upside is as long as your deck is properly built and is rot free it can usually be repaired or reinforced, if necessary, to use as the base for a roofed structure. If you are undertaking this type of work as a Do-It-Yourself project, it could be a good investment to hire an engineer, architect or professional builder to advise you about the structural design and support. Better safe than sorry!