Beach House

[mcrump]

I am designing a beach house that is supported on wood columns. The underside of the framing will be about 8' above the concrete parking pad. The area that the house is going to be built is a 160 mph wind load area. Any ideas on how to frame in the floor structure to the wood columns?

[Joe Carrick]

Michael,

Hire a Structural Engineer that has experience with this type of building.

[Ray C]

160! wow,,,, engineer

[sutcac]

Unless of course you love being sued.

[Curtis Johnson]

Michael:

You've received good advice so far... here's a link to FEMA and some of their publications which may be useful to your gaining some additional knowledge on the subject:

http://www.fema.gov/building-science...ons-flood/wind

[carpenterguy]

I wonder if you could find what you are looking for from the Wood Frame Construction Manual for high wind loads etc.

Here.

It is a prescriptive alternative to the IRC accepted throughout the states.

Andy.

[Joe Carrick]

I wonder if you could find what you are looking for from the Wood Frame Construction Manual for high wind loads etc.

Here.

It is a prescriptive alternative to the IRC accepted throughout the states.

Andy.

The problem is that without knowing the size of the house on top of the columns you can't calculate the lateral resistance needed. Is it 1 story, 2 stories? Is it 20'x20' or 80'x100'? At 160 mph the force per square ft of wall & roof surface is going to be very high. IAE, those columns will need to be embedded into the ground and will have to be able to take the full horizontal load without breaking. It's also likely that there is going to be storm surge which the columns need to resist.

Hire a Structural Engineer. That's what they do.

[gawdzira]

I know a guy at Boeing.

[HumbleChief]

I'm seeing a couple questions in the thread. One is the one you asked.."Any ideas on how to frame in the floor structure to the wood columns?"...Another seems to be the one that the responders have replied to which is how to engineer the member sizes and loads for the framing after you figure out how to..."frame in the floor structure to the wood columns?"

If the first question is one you want answered then from my experience any time you have a series of 'wood columns' you will also have a series of 'wood beams' with associated floor joists making up the floor system with walls etc. to follow. So if the first question is the one you asked then sink the columns, hang the beams off the columns and frame to the beams.

If you're asking how to size the columns and beams for the loads you stated (which I didn't read in your question) then of course you need an engineer to size and spec everything.

As they were rebuilding from Sandy I saw a TV show where they had a very, very nice home built on a column (post) and beam system and the columns were sunk deeply into the coastal sand, and in between the columns were sacrificial cmu block walls. The cmu walls were there to create a closed and finished look between the columns but if there was ever any storm surge, and there certainly was with Sandy, those block walls were designed to wash away without putting any stress on the columns that were holding up the home.

After those cmu walls were washed away the remaining columns created very little resistance to the wave action and the home weathered the storm quite easily and the home was damaged very little other than the cmu walls that needed replacing. Pretty slick.

[Joe Carrick]

Larry,

It's not just the sizing of the Columns, Beams and Joists. The connections themselves need to be able to withstand the Wind Loads. With the wind speeds indicated it would require some special connections. Everything would need to be calculated and specified by someone that knows what they are doing.

[Ron Ravenscroft]

I'm seeing a couple questions in the thread. One is the one you asked.."Any ideas on how to frame in the floor structure to the wood columns?"...Another seems to be the one that the responders have replied to which is how to engineer the member sizes and loads for the framing after you figure out how to..."frame in the floor structure to the wood columns?"

If the first question is one you want answered then from my experience any time you have a series of 'wood columns' you will also have a series of 'wood beams' with associated floor joists making up the floor system with walls etc. to follow. So if the first question is the one you asked then sink the columns, hang the beams off the columns and frame to the beams.

If you're asking how to size the columns and beams for the loads you stated (which I didn't read in your question) then of course you need an engineer to size and spec everything.

As they were rebuilding from Sandy I saw a TV show where they had a very, very nice home built on a column (post) and beam system and the columns were sunk deeply into the coastal sand, and in between the columns were sacrificial cmu block walls. The cmu walls were there to create a closed and finished look between the columns but if there was ever any storm surge, and there certainly was with Sandy, those block walls were designed to wash away without putting any stress on the columns that were holding up the home.

After those cmu walls were washed away the remaining columns created very little resistance to the wave action and the home weathered the storm quite easily and the home was damaged very little other than the cmu walls that needed replacing. Pretty slick.

YAA think it may have been designed by an Engineer. Most Eastern states require same near the ocean.

[Canuck]

No long drawn out thinking required here. I design in a high earthquake zone, three fault lines converge here, with high wind loads. Lateral design is a must on every design I do. While i know what has to be done and could design these items all the time, I only design the architectural plans and send them over to my engineer. Why take the chance of losing everything just so you can look like the professional of the year. I find a fat bank account more attractive than paying a lawyer.

[HumbleChief]

Larry,

It's not just the sizing of the Columns, Beams and Joists. The connections themselves need to be able to withstand the Wind Loads. With the wind speeds indicated it would require some special connections. Everything would need to be calculated and specified by someone that knows what they are doing.

Not quite sure how to put this but...duh. There's no question EVERYTHING would need to be calc'd and spec'd and I'm pretty sure that's why I typed, "of course you need an engineer to size and spec everything," but Ron kinda replied in the same vane so I must have written something that was ambiguous at best and read like I was suggesting that engineering was not needed, even though I wrote "of course you need an engineer to size and spec everything."

I'll have to work on my writing skills.

[HumbleChief]

No long drawn out thinking required here. I design in a high earthquake zone, three fault lines converge here, with high wind loads. Lateral design is a must on every design I do. While i know what has to be done and could design these items all the time, I only design the architectural plans and send them over to my engineer. Why take the chance of losing everything just so you can look like the professional of the year. I find a fat bank account more attractive than paying a lawyer.

Again, this seems so obvious. Are there designers/architects who DON'T use an engineer for such things?

Is that really what Michael was asking in the OP? Should he or should he not use an engineer to design/spec the framing (yes every part)?

If that's his question then it's a no-brainer yes. I thought maybe he was asking how to frame in the floor structure since those were the words he used..."Any ideas on how to frame in the floor structure to the wood columns?" Maybe he wants some ideas on how to frame the floor structure then send it to an engineer? What say you Michael?

[VHampton]

Again, this seems so obvious. Are there designers/architects who DON'T use an engineer for such things?

The real question is....is there a building department who would ever be willing to accept drawings for such a sensitive type of construction without engineered plans? Granted a basic house is one thing, but anything in the seismic zone or on the ocean is entirely another.

To help answer the original post...

FEMA guidelines are an excellent resource in terms of means and methods. Any home built near the water in what is known as the V zone (velocity zone) is required to be on pilings which are driven into the sand until they reach bed rock. Pilings are typically set at eight feet or ten feet on center. Lateral forces on the structure require the piles to be cross braced. All floor joist are strapped to the girders with ties downs made by Simpson or equal.

160 mile an hour wind zones also require every floor joist to be strapped to the girders which are through bolted to the piles. Every exterior wall stud is tied to every floor joist...every rafter is to be tied to every stud. High wind zone construction methods also require ridge beam and rafter connections along with header tie downs at all window and door openings. It's all in the wood framing manual and on the FEMA web site.

Here's a typical piling layout for a beach house....