Eagle Project Problem

[Neal McCormick]

I'm hoping someone here can provide some guidance -

My son is building a walking bridge for an eagle project. They have discovered that the creek bed over which the bridge will go is solid rock - they were unable to put piers into the creek (original plan was to build concrete piers in the creek onto which a post would be attached. Because of a variety of constraints, the bridge had to go in a particular spot. The guidance we got was to span the space - 20 ft - with 2 x 10's as joints on 12 inch centers. That was done and blocking was installed. At this time there is no deck on the structure. The problem is the deck substurcture has noticeable lateral sway - at least 4 6 inches to my eye. Anyone have any idea of how this could be stabilized? There is a thought that the decking will stablize it but I don't see how that could be - if the substructure sways, fastening more pieces to what is swaying is not stabilizing it. There is about 5 weeks left to get this done and my son is beginning to look more than a bit apprehensive. Can someone help us out here?

Thanks!

[John Shuk]

The decking should stabilize it. I will tie everything together so it can't sway because you have so many attachment points where it is held. I'm sure one of the engineers or architects can be more specific but I think you will be fine.

[Steve Knowlton]

Neal, You could put in some braces between the joists on a 45 to help strenghten it. The decking will help also. steve

[Lee DeRaud]

I agree with John that the deck will stiffen it a lot laterally, but if you're still nervous about it, put a long 2x6 (or so) diagonally on the bottom of the substructure, attached everywhere it crosses a joist or piece of blocking. As Norm says, "That's not going anywhere."

[Charles McKinley]

Hi Neal,

If the decking doesn't stiffen it up (I think it will.) I can fab up some steel reinforcements for you. I'm about 95 miles/2 hours from you. PM me if you need them.

Tell you son to relax it will all work out.

[Neal McCormick]

This forum is just incredible. Again!!

[Andy Henriksen]

Hey Neal,

Just curious if you/your son/the landowner got a permit for this project. A pain in the butt, no doubt, but I would think it would be an important component of the project, teaching your son the right way to do something like this, and be a good intro to him into government bureacracy and red tape.:o I don't really care, personally, but would hate for ya to get in trouble over an otherwise positive project.

[Joe Pelonio]

I recently built a deck 5' above ground 10' x 25' and the inspector
made me add diagonal 2x6 braces between the joists, though it
felt fine after the decking went on. Better to be safe I guess.

[Neal McCormick]

The bridge is part of a much larger undertaking. One of the local fruit growers in the area agreed to donate the use of a large parcel of land for community youth sports fields. There will be 3 fastpitch softball fields and a full size soccer field. The owners grand daughters participate in both of those sports. In our area, athletic fields are at a premium, particularly for the young ladies. (The soccer field is not limited to the girls but the softball fields are). The owner has secured all the necessary approvals for all work being done on the property which meant Tim did not have to pursue those. I'm told the local zoning inspector has been to the site and to this point has had no issues.

In anticipation of a very wet Sunday we stacked all the wood onto the portion of the deck that was swaying. The sway disappeared so we are thinking we are going to be ok.

Thanks again for all your suggestions and offers of assistance. This is an amazing place - folks like you should be role models for all.

[Jeff Sudmeier]

As was said, the decking should stabalize it wonderfully. It is amazing how much of a difference that makes! If it doesn't. Blocking at 45's between the joists will take much more of the sway out.