water tight decking

[farmerpsv]

Hey CurlyDave,

I already have the ledger in place, it's a 2x10. all of my joists going from the house to the posts will be double 2x10s (8 posts). the joists between the double 2x10s will be 2x8s on 16" centers. because of the placement of the ledger and the size of the joists, i only have so much space left for flooring. i originally was going to do tile, but am concerned about the added weight. i imagine i'd need 1 1/2 " of sub floor for stability...thats what i usually use when i tile. add the weight of the tile and hot tub, seems heavy.

 

[CurlyDave]

Have you had an engineer look at your plans?

I suspect you can keep the existing ledger board, its load carrying capacity will be determined by the way it is fastened to the house studs.

I have never been a big fan of the construction I think you are describing. If I have this right, the 2x8s on 16" centers will be parallel to the house wall. If you put the right beam on top of your posts, you could use 2x10s on 16" centers perpendicular to the house for about the same lumber cost and I think you would have a stronger structure.

Take a look at the span tables here: span tables .

You can design the deck for any load you want.

I would consider putting one extra post directly under the hot tub and I bet you could use tile or stone as a surface.

 

[farmerpsv]

CurlyDave,
the joists are perpendicular to the house. each post will have a double 2x10 joist, then there are single 2x8 joists 16" on center between each double joist. i will cantlever the joists on a double 2x10 beam that will be attached to 6x6 posts. the porch is wrap around, L shaped. the hot tub will sit on the inside corner of the porch, or corner to corner up against the house (to put it another way). i already have the lower deck built and put a post under the diagonal joist that spans 14' from the corner of the house to the corner pier. I put a 4x4 under that near the house for added support. i plan on taking the 1x6 corner trim off the house and replacing it with a double 2x6 corner for added support for the upper diagonal joist, where the hot tub will be. didn't have an engineer, did get it approved by the county engineer (though they don't know about the tub plans!). also, 2x10 ledgers are attached to the house with2- 1/2x5" bolts every 24" (county spec calls for 1 every 23"). I may end up using under deck gutters. when constructing the deck they can be used under the decking on top of the joists, so that would avoid exposing all the framing to weather.
paul

 

[CurlyDave]

I would find a local engineer and show him your plans (tell him about the tub).

This will save you money in the long run. He will size the joists correctly for the loads the deck will see.

You may save enough on materials to cover his fee, or you may have to beef it up a bit, and you will be far ahead to know that before you build.