Tall Deck Construction Question

[DerbyDad03]

I was reading a Q&A on buildng a tall deck which contained the following exchange.

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Q: My house has brick veneer over insulated stud walls. I am going to build a raised deck off the second floor bedroom. It will be suported by four posts, Should I attach the deck floor to the house wall?

A: It is probably better if you do not attach it securely to the house wall. With tall wooden posts, the deck suface may move up and down more than the house wall throughout the seasons.

To provide a more stable feel to the tall deck, screw steel angles to the house wall. Screw another set of angles to the deck several inches below the other ones. Connect them with long bolts to allow some vertical movement.

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Can I assume that the bolts are to be left loose to allow for vertical movement? How loose? Regarding the "stable feel" the author mentions

- would that be present because the loose bolts would supposedly limit the horizontal movement somewhat?

Is this a common construction method for tall decks?

[RicodJour]

No, and the reasoning isn't logical. Wood moves seasonally due to changes in moisture content, in width and depth, not length. The other factor is wood's coefficient of thermal expansion - which is totally negligible in the normal range of climactic conditions.

There's far greater risk of movement due to insufficient footing depth and consequent frost heaving - and that can happen, in the same amount, regardless of the post length.

R

[ransley]

Building a deck like that without permits, plans and and inspection you risk having to remove it later. The city and inspectors are there to help, Ive just been through a porch redo where initialy we were told to remove and replace it at 60,000, we cleared the violations finaly for 3000.00 .

[hallerb]

or worse a deck collapse, with a high one people can die

[dpb]

No and the two other respondents (so far) have good points ... if you're contemplating the same thing as the poster you quoted, the key for stability is the footings and sufficient lateral bracing and adequate piling dimensions (a 4x4 isn't sufficiently stiff at those lengths).

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[DerbyDad03]

re: Building a deck like that without permits, plans and inspection you risk having to remove it later.

Thanks for the response, but I don't see anything in the Q & A that says this deck is going to be build without permits, plans and inspection.

This isn't my deck - I'm simply curious about the construction method

- but for the sake of argument I'll tell you what I did before I built my deck, which is 6' off the ground.

I looked at various raised deck plans and I asked a lot of questions, including whether I should attach it to the house. I then submitted a set of plans that I was pretty sure were going to pass first time - which they did. I'll give the questioner the benefit of the doubt and assume he is simply gathering the information required to put together his permit request.