pavilion build help!

2001kx · 09-03-2009, 01:10 AM

im building a 10' x 20' pavilion.
first big build for me and i think i made a mistake.

i used 6 treated 4 x 4 posts and 2x10's all around boxing it up but the whole building will wobble when i push on it.
i wish i would have used 4x6 but its too late now (im in the process of laying shingles now)

so my Questions are.

will the 4x4's be ok?
what is the best way to stiffen this thing up?
what can i do to save my project?

thanks in advance.

here are some pics

PaliBob · 09-03-2009, 05:56 AM

Welcome to the Forum
Too bad you didn't come aboard in the planning stage.

Need more information:
e.g. location?, Concrete slab?

and pics:
http://www.diychatroom.com/f19/how-attach-photo-post-12559/
.

Willie T · 09-03-2009, 08:36 AM

There are probably numerous ways to stiffen your project up. But Bob's right. At this point, we really have no idea what you have. Pictures sure would be helpful.

2001kx · 09-03-2009, 11:08 AM

i will get a pic of it.

2001kx · 09-03-2009, 12:26 PM

pics added

Willie T · 09-03-2009, 12:41 PM

A couple of 45 degree top braces on each post, fastened somewhat like these pictures show will go a long ways toward stiffening up everything. About 3 or 4 feet long. And bolted, not screwed.

And, yes.............. They really should have been 6x6's.

The second one shows how you could do it with plywood gussets. Only real trouble with this is that you create a pocket that will trap water (rot is very possible).

vsheetz · 09-03-2009, 02:11 PM

yup - triangulation is your friend

i see what appears to be a 2x4 placed in a corner to counteract racking, I would suggest to beef this up and positively connect it as well at all four corners.

2001kx · 09-03-2009, 02:14 PM

Quote:

Originally Posted by Willie T

A couple of 45 degree top braces on each post, fastened somewhat like these pictures show will go a long ways toward stiffening up everything. About 3 or 4 feet long. And bolted, not screwed.

And, yes.............. They really should have been 6x6's.

The second one shows how you could do it with plywood gussets. Only real trouble with this is that you create a pocket that will trap water (rot is very possible).

ok i will give that a shot,thanks.

what kind of load can the 4x4's handle?

2001kx · 09-03-2009, 02:16 PM

Quote:

Originally Posted by vsheetz

yup - triangulation is your friend

i see what appears to be a 2x4 placed in a corner to counteract racking, I would suggest to beef this up and positively connect it as well at all four corners.

yeah i just did that as a quick fix to see if it would help.
im going to get some more 4x4's for all the extra bracing.
thanks for all the help everyone.

should i run another row of 2x10's on the inside?

positively connect it as well at all four corners.

what do you mean by this? lag screws?

im new to all this so be patient with me-lol.

Willie T · 09-03-2009, 02:40 PM

Quote:

Originally Posted by 2001kx

ok i will give that a shot,thanks.

what kind of load can the 4x4's handle?

It isn't so much how much of a load the 4x4's can handle, but the way in which they are being asked to handle it.

4x4's can handle tons. I mean look at two story houses that are held up with much smaller lumber...... BUT these are not single, free standing sticks with no lateral support. The external and interior wall coverings become an integral part of the bracing structure that keep the vertical sticks from bending and snapping.

4x4's are relatively skinny for that much length. 6x6's would resist unbraced bending a lot better. Google "Moment of Inertia" for a better understanding of this. If the 4x4 never gets an opportunity to flex or bend, it will handle massive loads. But let it begin to bend a little, and the strength factor it started with is severely and rapidly reduced. And the longer the 4x4, the more susceptible it will be to this weakness.

Willie T · 09-03-2009, 02:47 PM

Quote:

Originally Posted by 2001kx

yeah i just did that as a quick fix to see if it would help.
im going to get some more 4x4's for all the extra bracing.
thanks for all the help everyone.

should i run another row of 2x10's on the inside?

positively connect it as well at all four corners.

what do you mean by this? lag screws?

im new to all this so be patient with me-lol.

I would say "No", simply for the fact that you really don't need to be adding any more weight up there. Your span appears to be sufficiently short for the support and load you have... although I'm not an engineer, so I can't say with any legal certain.

Willie T · 09-03-2009, 03:03 PM

Only one suggestion I might make. (We're all going to overlook the posts being buried.... You DID paint them with some waterproofing first, right?)

I see you used 2x4 pieces to rest the 2x10's on. You probably lagged the 2x10's to the posts? I would replace the lags with through-bolts (with large washers) since it's a good bet you didn't cut the 2x10's into the posts for vertical support.

2001kx · 09-03-2009, 03:16 PM

Quote:

Originally Posted by Willie T

Only one suggestion I might make. (We're all going to overlook the posts being buried.... You DID paint them with some waterproofing first, right?)

I see you used 2x4 pieces to rest the 2x10's on. You probably lagged the 2x10's to the posts? I would replace the lags with through-bolts (with large washers) since it's a good bet you didn't cut the 2x10's into the posts for vertical support.

no i didnt notch anything.
and no i didnt paint the bottoms in the ground either...i thought being treated would be good enough?
i did use lag bolts for the 2x10 to the posts.
should i use lag bolts to hold the supports i will be adding?

Willie T · 09-03-2009, 03:32 PM

Here's a good way to overlap 2x material, using through bolts. Note that the overlap on this 6x6 is a "centered" 3", notched into the 6x6 the depth of a 2x (1-1/2"), leaving a solid 1-1/2" of each joist fully resting on the notched post at either end.

The joint you see here is called a "half-lap", one of the most useful and effective in framing.

I hardly ever use lag bolts when there is the opportunity to use through bolts.

Willie T · 09-03-2009, 03:41 PM

Don't get discouraged. The way you built is totally sufficient, and the way many people do all over this nation. Your work will probably last well into your children's adulthood. It's just neater to think of your great grandchildren eating under that shelter one day.

BTW, since you're just starting those shingles, make sure to tar down all the edges. (about 3" worth) That's where rain and snow melt get under to begin rotting the plywood and fascia. All your fascia wood should be pre-painted (all 6 sides) before installing for the same reason.... scarf cut joints too ( One in 100 carpenters paint the joints anymore... sad.)