Hurricane ties… trusses… nailing
davidmeiland
| Posted in Construction Techniques on
With walls sheathed before standing, where do you guys nail the hurricane ties for the trusses? I’d like to shoot them on the exterior side of the wall, because that way the HT catches the top chord of the truss rather than the bottom chord, and it also isn’t inside to bulge the drywall. But, the nails have to go thru the 1/2″ CDX.
If installed on the inside, the nails are all directly into to the plates, but they’re also into the bottom chord of the truss, so uplift has the be transferred thru the truss assembly plate.
Whaddya say?
Replies
I'd say just using them at all is putting you way out in front of the pack. (unless you live in one of those areas where they're required.)
If you're worried about the issue with the thickness of the plywood, can you get longer nails?
When I was in Iowa, the straps I used were about 5 inches long, with a half twist. so, you're right, they wouldn't catch very much of the top cord if used on the inside. But again, we weren't required to use them. I just did it because I felt that it was the right thing to do. Here in florida, you're required to use these huge honking straps that actually wrap up and fold over the top of the truss. Of course, there's not a lot of wood exterior framing to worry about. mostly concrete block with a bond beam poured on the top course that those straps are then set into. Talk about a whole different world!
Don't Know about your area but here they go on exterior under siding to the top chord.
Would be to easy to nail from the inside.
I use a Teco nailer alot !
IMHO tie-downs SHOULD be nailed in through the exterior sheathing. Otherwise putting them on is a waste of time.
If the ties are nailed to the inside of the top plates, what holds the top plates down? Just a few nails driven down through the top of them. And maybe some nails through the ply on the outside.
But the ply is 3.5" away, so the top plates can still twist and lift up. And once they twist they would make a mess of the nail holes and nails, making them basically worthless.
If the ties are on the outside, the nails on the bottom of the strap goes through the plywood. And you're nailing into the side of the top plates that are held down by the plywood.
I also believe that the walls should be anchored down. Everything should be tied together from the foundation up to the roof system.
a few of those tied together nw florida houses went floating in the sound during hurricane opal
Thanks all for the replies.
Boss, good point I had not considered. The top plate is nailed 8d 6" OC thru the ply, and a few spikes down thru into the lower plate, but the HTs could twist that if there were a lot of uplift.
Outside they go.
I got two BI callouts (seperate inspections/inspectors) for HT's last year because I insist on them being OUTSIDE, through the ply on every other rafter.
The BI's only looked for them on the inside because that's where everyone else in town puts them.
Troy Sprout
Square, Level & Plumb Renovations
David, I live in Mobile, AL, in a 100-140 MPH high-wind zone. We use 12" or 16" twisted straps--the top goes up the side of each rafter/truss, wraps over the top, and down the other side some. The bottom goes down the interior side of the plates to either the edge of a stud, or if it's in between studs, it's folded around the underside of the two top plates. Most framers in my area put 3 nails each top and bottom and get away with it; we fill every hole (sometimes 20+) with Paslode joist hanger nails.
As BH stated, the walls are held down by 2 means: 1, by the plywood, 8d nails 4" edge/ 8" field nailing, and 2, the "Go-Bolt" system--it is basically a piece of 1/2" all-thread that couples to a special anchor bolt at the bottom and has a nut and 3" square washer on top of the double plate. These are placed at each corner, on each side of an opening, and every 6' in between. They cost us between 10 and 12 bucks each, and a typical 3,000 SF house with use 30-40. However, if we don't use these, we have to use SPH4/6 "U straps" at every stud, top and bottom, so the cost is the same, roughly.
We are also required to strap gable end studs, build "ceiling diaphragms", and clip ceiling joists at each end of any porch or carport, in addition to using OSB sheathing for the ceilings of said structures at the roof plywood nailing schedule--we used to just strap porch ceilings with 1x4's for the vinyl installer.
Do a search for "Go-Bolts" as they have a website that will give you more specific info.Jason Pharez Construction
Framing Contractor
The inspector came today as we were blasting the last of the HTs onto the outside. Not even a blink.
We get the occasional job here where the engineering is like what you describe. Huge pieces of MST strap horizontally and vertically, 3/4" all-thread from the foundation up thru each floor with PHDs everywhere. Sometimes those jobs come from an engineer that got sued in the past.
Did you end up using longer nails?We put most of our straps on the inside, but when we do put them on the outside, we use at least 2" nails. The PP nails we usually use are 1.5" 10d.
We used 1-1/2" PP nails. Inspector liked 'em fine. I can see the argument for using 2-1/2" and will order a box next time I'm getting nails shipped.
How's the framing business treating you Jason? Are you glad you came over to the 'dark side' with the rest of us subs?View Image
To the OP, sorry for the hijack...it'll be real quick LOL.
Diesel, we framed two houses for a large builder here and then a couple of weeks ago their work just dried up! I spent two weeks playing Mr. Mom until I was bored out of my mind. Ended up helping out my old boss for a week, and that was kinda nice (not having to be the boss).
Spent yesterday going all over the next county fixing other framers' errors for the same aforementioned builder, and have more fixes to do tomorrow. Next Tuesday we should be starting a new house--small, on a floating slab. It won't pay that great but it's right on the water at Mobile Bay--the view is wonderful.
Things are still a little tight here with me not working for a couple of weeks (and having to pay quarterly taxes-DOH!), but I don't regret going to new framing at all. And with all the hacks around here getting fired from the job, it won't take me long to build my reputation, just like I did for my remodeling clients.Jason Pharez Construction
Framing Contractor
Not a problem at all. I'd much rather know what you're doing.