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nick_sulkowski

Building codes for porch columns

9 years ago
last modified: 9 years ago

Got a question guys. I noticed the new homes (identical to mine) going in my neighborhood have 3 big thick, 6X6 ish greenish treated timber columns, then sided, used to hold up the front porch. For mine they used only two 4X4s and I'm not sure they're treated. I'm still in my 1 year warranty period so I'm wondering if this is a code violation or not. If so I will have them redo. Thanks in advance. Oh by the way I live in Arapahoe County Colorado.

Comments (6)

  • 9 years ago
    last modified: 9 years ago

    Just pulled off some siding. See the photo. The wood was very water logged at the bottom where it meets the cement. Again, I can't tell if this is treated lumber or not. Can someone chime in? Actually looks like redwood to me.

    Questions:

    1.) Do I need to seal this wood where it meets the concrete? If so how? I'm worried the will eventually rot.

    2.) The other homes I mention earlier actually have 3 column's and they are big thick timbers, like 6x6. I only have two 4x4. See pics. Think I'm ok with this???

    Thanks all!

  • 9 years ago

    The column caps can easily be hidden by the trim boards.

    Although, it is not specifically required by code, I always use a post base with a standoff for added protection. The post base is also a more secure/easier connection for uplift.


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  • 9 years ago
    last modified: 9 years ago

    What was built is not likely to meet the building code anywhere but you need to ask the local building department what your code says and look at what is on the permit drawings while you are there.

    For reference, the 2012 IRC says:

    SECTION R317 PROTECTION OF WOOD AND WOOD BASED PRODUCTS AGAINST DECAY

    R317.1 Location required.
    Protection of wood and wood based products from decay shall be provided in the following locations by the use of naturally durable wood or wood that is preservative-treated in accordance with AWPA U1 for the species, product, preservative and end use. Preservatives shall be listed in Section 4 of AWPA U1.

    1. Wood joists or the bottom of a wood structural floor when closer than 18 inches (457 mm) or wood girders when closer than 12 inches (305 mm) to the exposed ground in crawl spaces or unexcavated area located within the periphery of the building foundation.

    2. All wood framing members that rest on concrete or masonry exterior foundation walls and are less than 8 inches (203 mm) from the exposed ground.

    3. Sills and sleepers on a concrete or masonry slab that is in direct contact with the ground unless separated from such slab by an impervious moisture barrier.

    4. The ends of wood girders entering exterior masonry or concrete walls having clearances of less than 1/2 inch (12.7 mm) on tops, sides and ends.

    5. Wood siding, sheathing and wall framing on the exterior of a building having a clearance of less than 6 inches (152 mm) from the ground or less than 2 inches (51 mm) measured vertically from concrete steps, porch slabs, patio slabs, and similar horizontal surfaces exposed to the weather.

    6. Wood structural members supporting moisture-permeable floors or roofs that are exposed to the weather, such as concrete or masonry slabs, unless separated from such floors or roofs by an impervious moisture barrier.

    7. Wood furring strips or other wood framing members attached directly to the interior of exterior masonry walls or concrete walls below grade except where an approved vapor retarder is applied between the wall and the furring strips or framing members.

    R317.1.1 Field treatment.
    Field-cut ends, notches and drilled holes of preservative-treated wood shall be treated in the field in accordance with AWPA M4.

    R317.1.2 Ground contact.
    All wood in contact with the ground, embedded in concrete in direct contact with the ground or embedded in concrete exposed to the weather that supports permanent structures intended for human occupancy shall be approved pressure-preservative-treated wood suitable for ground contact use, except untreated wood may be used where entirely below groundwater level or continuously submerged in fresh water.

    R317.1.3 Geographical areas.
    In geographical areas where experience has demonstrated a specific need, approved naturally durable or pressure-preservative-treated wood shall be used for those portions of wood members that form the structural supports of buildings, balconies, porches or similar permanent building appurtenances when those members are exposed to the weather without adequate protection from a roof, eave, overhang or other covering that would prevent moisture or water accumulation on the surface or at joints between members. Depending on local experience, such members may include:

    1. Horizontal members such as girders, joists and decking.

    2. Vertical members such as posts, poles and columns.

    3. Both horizontal and vertical members.

    R317.1.4 Wood columns.
    Wood columns shall be approved wood of natural decay resistance or approved pressure-preservative-treated wood.

    Exceptions:

    1. Columns exposed to the weather or in basements when supported by concrete piers or metal pedestals projecting 1 inch (25.4 mm) above a concrete floor or 6 inches (152 mm) above exposed earth and the earth is covered by an approved impervious moisture barrier.

    2. Columns in enclosed crawl spaces or unexcavated areas located within the periphery of the building when supported by a concrete pier or metal pedestal at a height more than 8 inches (203 mm) from exposed earth and the earth is covered by an impervious moisture barrier.

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  • 9 years ago
    last modified: 9 years ago

    Gentlemen! Can't thank you enough for the thorough and thoughtful replies. I'm certain they did use galvanized post bases, but they anchored the post bases to the footings deeper down. Then poured the slab over the dirt and footings thereby surrounding the beams. Does this change your thoughts on anything?

  • 9 years ago
    last modified: 9 years ago

    Since the post is clearly pressure treated, there are NO visible code violations, although creating a dam around the post to continually hold water is inherently inept. That leaves the only possible violation, the trim board used to wrap the post, being too close to the concrete, but most trim boards like you have are "Treated with our SmartGuard process to resist termites and decay", and this means "to the core", unlike (better than) conventional pressure treated lumber.

    http://lpcorp.com/resources/product-literature/brochures-sales-sheets/lp-smartguard-one-sheeter-brochure/

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