First Timber Frame Build - Gazebo

[tadamson]

Hi all, new to forum.  Looking for some help...sorry for the long post and hopefully my attempt at explaining my challenges and potential solutions is understandable.  I'll try to work on a drawing as well.

I am getting ready to build my first timber frame structure.  I'm not going to lie, I'm a bit nervous!  It will be a 12x12 gazebo using plans from timberframeHQ.com.  The structure will be built in conjunction with a deck that will be cantilevered over our new pond.  As seen in the pic, I have 12 piers poured.  The four corners of the structure will sit on the ones with brackets on them (the piers in the water will support an uncovered deck).  

This build has several challenges....

1. The middle piers are all about 1" lower than the rest, so I'll need to figure how the best way to level everything.
2.  I'm not ready to install the 4 8x8 posts for the gazebo because I haven't cut the joinery yet.  Still, I would like to build the deck now and install the posts when ready.
3. Not all the piers are installed perfectly.  The plans for the gazebo call for 12'x12' post layout, but the piers ended up more like 12'6" x 12'6".

My plan, so far, is to run the main support beams across the piers (basically from the bottom of the pic to the top of the pic and parallel to the pond), then run joists between them.  I'll be using all 2x6 material since we want to keep the deck as close to the water as possible.  I've gone back and forth on this, but I'm now thinking I will secure the beams directly to the anchored post bases and bypass posts (except for the 4 used for the gazebo).

I think I can fix problem #1,  but looking for some thoughts on #2 and #3.

I have two ideas on how I could install the deck framing without actually installing the gazebo posts, please let me know your thoughts.

**Keep in mind, my plan is to have the deck framed wider than the gazebo, so the main beams need to extend past the 8x8 posts.  This will allow a picture frame around the 8x8 posts.

A.  Double up 2x6 beams, cut a notch to accept the 8x8 posts.  The 8x8 posts would have an open mortise in the end that I could insert over top when ready and then mechanically tie the post and beams together with the post base. In this example, the 8x8 beam would be connected directly to the post base, which is anchored to the concrete.  I would likely install some temporary posts and stub them out of the decking.  Then when ready, remove those and install the real posts.

B.  Take 5 2x6 beams and run them into the post bases directly and attach the anchored post base to the beam.  Then cut a mortise to accept the 8x8 post, which will have a tenon, and mechanically connect the post to the beam.  In this case, the post would not be directly attached to the post base, the beams would.

Option B would allow me, in theory, to locate the mortise where I need to in order to get the posts back to a 12'x12' layout.  The post doesn't have to necessarily be directly over the concrete pier.  Option A would tie me to the 12'6"x12'6" layout, which somewhat renders my plans useless...or at least in need of modification.

I was thinking that Option B is somewhat similar to a sill/post connection and might work?  Is there a better option?

[everythingwood]

If it were mine I would definitely head down the option B route.  Build a solid floor on the posts and attach the frame to the floor.  However I don't think a single 2x6 rim joist is going to cut it.  Six feet isn't that much of a span but I would be going with doubled 2x8's for a more solid floor system and add extra framing around the posts for a solid connection.  Treated of course.  In the book Learn to Timber Frame (Beemer) they show a timber frame attached to a conventional stick-framed floor.  In the book they rely on the sheathing to hold the frame down.  If it's an open sided structure I would look at a longer tenon inserted into a formed "mortice" with bolts to secure it where pins would traditionally go.  Or, they make systems for fastening posts to concrete that might work if you can fasten the plate to the floor.

[tadamson]

Thanks for the thoughts.  I do have Mr. Beemer's book and will take a look at your suggestion!

[bm.stanford]

I can add no technical advice but I will say what perfect place for a pavilion.  Well thought out and landscaped.  You should post pictures of the completed project!

[tadamson]

Thanks, I will try to post some pics as I progress.