FAQs: Decks - Fairfax County, Virginia

It's possible that your neighbor chose to obtain a permit using the Fairfax County Typical Deck Details in lieu of professionally designed plans. When applying for a permit, you may choose to use our engineered plans to build your deck as long as you follow the guidelines and restrictions outlined in the document. Please note that if, upon inspection, you failed to follow the prescribed guidelines, you will be required to submit your own custom designed plans which must demonstrate that your deck meets all applicable building codes.

I've been building decks for 30 years, and not a singe one has ever collapsed. Why do I have to submit a drawing every time I apply for a permit?

State law requires a plan submission with the application of a permit. However, if the deck you frequently build falls within the criteria set forth in our typical deck details, then you do not have to submit plans for each project. Any deviation from the prescribed plans will necessitate a detailed plan submission for each and every project.

What are the maximum dimensions for a deck using the Fairfax County Typical Deck Details?

The maximum dimension from your house to the outside of your deck using the typical details is 21'. This figure is based on a 2x12 joist at 16" on center spanning 18' from the house to the beam and overhanging past the beam 3'. As long as there is solid material to attach the deck to, and there are no zoning restrictions, the joists can be spaced at 16" for the full width of the house.

What design considerations would prohibit me from using the Fairfax County Typical Deck Details?

The following, in addition to any deviation from the typical details, are some of the items that require a complete plan submission:

Multi-level decks.
Multi-span decks.
Spiral stairs.
Hot tubs.
Roof structures of any kind.
Privacy screens.
Decks for a commercial building.
Attachment to or through a brick veneer.
Attachment to a house overhang or bay window.

Can I use specific sections within the typical details, and only submit drawings for customized components?

Yes. Any conditions which deviate from the typical details must be drawn to scale and thoroughly detailed to adequately show the intended design, include fasteners.

I recently bought a home that already has a small deck. Now, I want to enlarge it. Should we tear out the old deck, or can we use your typical deck details to add onto the existing one?

You may certainly use the typical deck details as long as the new deck addition does not attach to the old deck in any way. In most cases, this would be like having two separate decks side-by-side. If you want to change any part of the old deck, or connect the two decks together, then you must submit a set of detailed drawings for both the existing and new decks.

I just finished building my deck per the typical deck details. I now want to remove the back door and install wider French doors. May I install the new door using the same permit?

That depends. If you have received your final inspection or if a different contractor is to perform the work, a new permit must be obtained. However, if you have not yet received your final inspection and the same contractor will be installing the new doors, then you can amend your existing permit to include the new work.

The headers over each opening support the weight of the wall itself, any second or third story floor weight, plus roof weight (snow loads). Wider openings will require new headers that must be carefully designed to ensure that the new header and framing around each door/window will safely support all the loads.

Can I place a hot tub on my deck?

The addition of a hot tub places a tremendous amount of concentrated weight on a small area of decking. A hot tub should never be placed on an existing deck without a design analysis to ensure the deck's structural stability. In most cases, reinforcing is required.

If you are in the planning stages for a new deck you must know the hot tub's model number, model specifications, and manufacturer's installation guidelines so that the deck can be properly designed.

For more information on the installation of a hot tub, see Pools, Spas & Hot Tubs.

What conditions would warrant the construction of a free-standing deck?

You would be required to construct a free-standing deck when utilizing the Fairfax County Typical Deck Details if:

Your home's band board is made of plywood, a manufactured wood joist, or any material less than 1 1/ 4" thick.
The floor joists of your home are open web trusses.
Your home has a brick veneer.
There is any type of overhang in the area where you want to attach the deck to the house. Decks cannot be attached to a bay window or chimney.
The elevation of the deck is above the house band board. Decks cannot be attached to a stud wall using the typical deck details.

Can I build a screened-in porch or a sunroom on my existing deck?

Zoning regulations may prohibit your deck from being converted to a screened-in porch or sunroom. If zoning poses no restrictions, the existing deck must be specifically designed to resist the additional loads imposed by any new construction, like snow and/or wind loads.

I built my deck exactly according to your Typical Deck Detail, and then added some decorative lattice beneath it. The inspector made me remove the lattice. Why can’t I have lattice on my deck?

The answer to this question involves zoning ordinances and not building code requirements. A deck that has no coverings is considered an open deck. If you add lattice work above and below, the deck is then classified as an addition and, therefore, must meet the set-back requirements for a home addition.

I would like to use your Typical Deck Detail, but I was told that I cannot use composite green decking/railing materials. Why would Fairfax County stop me from using recycled or synthetic products?

You may certainly use our typical deck details and substitute the traditional timber decking with an approved composite or synthetic product. The listing of approved products can be found at:

www.fairfaxcounty.gov/dpwes/construction/str_plastics.htm

This can be done without a plan submission if you make the evaluation report for the approved decking material available to the inspector. Evaluation reports can be found at the website above.

You may also substitute an approved rail system. However, a plan submission is required. During the permit application process, your submission for plan review shall include the deck plans, which can be supplemented by the typical deck details, the evaluation report from the website above, and an attachment detail of the rail system to the deck.

Please be aware that a manufacturer’s advertising brochure, technical specifications, a report of their testing methodology, or test results, will not be accepted. You are strongly advised to visit the website listed above prior to purchasing a composite or synthetic decking or rail system.

How can I determine what type of band board I have in my house if I have a finished basement?

Band boards are typically attached to the ends of the floor joists in order to prevent the floor joists from toppling over. Many band boards may also support the load imposed from a deck through the connection of the ledger board. If you have an unfinished basement, you can look between the joists to determine their composition. However, finished basements present a difficult hurdle. You may consider these options:

If available, your home’s original building plans will specify the type/dimensions of the band board. Fairfax County retains building plans for two years after final inspection. Telephone 703-324-1895, TTY 711 for more information.
Look in an unfinished area like a laundry or utility room since these area are generally not finished.
Check a neighbor’s house that is similar to yours that does not have a finished basement.
If all other methods fail, you may choose to use a free-standing deck.

I have a brick veneer on the back of my house. Can I attach a ledger board to it?

The building code stipulates that absolutely nothing shall be supported by, or attached to, a brick or stone veneer. If you do want to attach to a veneered house by transferring the load from the ledger board through the veneer to the band board, a professionally designed attachment detail must be submitted to the county for a thorough review during the permit application process.

Can I use sono-tubes for my concrete footings?

Sono-tubes which are 18" in diameter or greater can be used as a pre-fabricated concrete form for your solid footings when using the typical deck detail. You may also pour a 16" square or 18" round by 8" thick footing as shown in the typical details and, once the concrete has set, place a 12" diameter sono-tube on top and pour concrete up to grade. In no case shall a 12" sono-tube be used as the sole footing for a deck post.

I purchased notched 4x4 posts from a local home center store to use as my guard post. The inspector rejected it. Do I have to completely rebuild my guardrail?

The typical deck details specifically state that guard posts shall not be notched. The structural capacity of the post is significantly reduced as soon as it is cut or notched. Given the importance of a deck railing, notched posts are prohibited.

Last year, I used the Fairfax County Typical Deck Details to build my deck. Can I add a small stairway this year without getting another permit?

When you received the final inspection on your deck, that permit was closed and cannot be used again. The addition of a small stairway may seem incidental, but it does require a permit and building plans, and must be reviewed by the applicable departments within the county (i.e., Zoning, Site, Building Plan Review, etc.).

Why can’t I use a pre-fabricated galvanized connector between the 6x6 posts and the double beam?

Most metal connector companies do not manufacture an adequate connector which will connect a double beam to the top of a 6x6 post in a 1.85 oz/sf zinc coating. The notched 6x6 bolted to the double beam, as shown in the typical details, provides the most effective and least expensive connection.

Can I use a slightly larger nail instead of buying exterior screws?

No. The connections in the typical deck details were designed specifically for the fasteners shown. When an option is available, it is so labeled in the details. Wood screws have a greater ability to resist pull-out forces than a nail, and the loads in some connections dictate the need for wood screws.

I want to build my deck per county detail so I don’t have to draw up plans. Where do my beams have to be placed?

If you are attaching your deck to your house, the location of the beam would be based on your choice of joist. The beam would be placed at or within 3' of the end of the joists. If you are building a free-standing deck, and additional beam will be required within 3’ of the house.

I want to use 3 members for my beam. What will be required on the plans?

The size of the members, how each of the 3 members are attached together, and a complete detail of the beam-to-post connection.

You can just give us a guard infill detail showing the span of the top rail, the top rail attachment to the post, the post attachment to the deck, the length of the pickets, and the attachment of the pickets to the top rail and bottom rail or deck. Then just note on this detail that the rest of the deck will meet Fairfax County Typical Deck Details.