Roof Trusses

[Shultzy]

To make the roof trusses for my workshop I'm going to use nail plates mainly for speed. I'm used to normal nails! (circa 3mm flat head). My question is are there nailers that use these types of nails, as those I've seen use 50mm and above, or am I doomed to put them in by hand. Also is there any rule of thumb to work out how many nails to the Kg?

 

[SketchUp Guru]

I guess I can't answer regarding the nail plates. When I built my shed, I used 1/4" plywood for gussets. these were glued and nailed in place. I used finishing nails to hold the gussets in place but the glue does the work of keeping the trusses together. They are rock solid that way. The plywood, glue and nails were cheaper than metal nail plates and didn't add much time to the construction.

 

[JFC]

Can i ask why you are making trusses and not cutting and fixing the roof ?

 

[jasonB]

The air powered palm nailers are designed for driving 30mm square twist hails used for joist nangers etc if you mean you are using metal plates.

If you are just nailing ply gussets then you need a roofing nailer that takes the coils of nails as these have larger heads.

Unless its a very big workshop whats wrong with a good old claw hammer?

Jason

 

[mel]

is there any reason why you are not buying youre roof trusses from a roof truss plant , they come with the nail plates already pressed in
it may be worth enquireing . as they sometimes have trusses made for a job and someone has measured incorrectly although ive never done that you understand

 

[ike]

I made my roof trusses with 1/2" sheathing ply for the gussets, cascamite glue and screws. The glue alone does the job.

ike

 

[Shultzy]

DaveR - Hadn't thought of the ply gussets for the roof trusses, I've only used them for shelf supports.

JFC - The workshop will have a pent roof. Its a right angled triangle,base 8'8", hight 18", slope 11' with 6" overhang at top and 24" at bottom, and has a central vertical piece. Its made from 4x2 on end. I've chose this design to allow light in through the vertical space.

JasonB - I need about 1250 for the roof trusses, 2200 for the cladding and 350 for the studding. Thats a lot of hammering, just thought a nail gun would be a bit easier on the joints.

mel and john - These trusses would be counted as specials, and anyway I like the idea of doing it all myself.

 

[SketchUp Guru]

FWIW, when I made mine, I laid them out with a CAD program (pre-SU) and figured out all the dimensions. Then I cut all the pieces for the timbers and the gussets. When I was ready to assemble them, I laid the first one out on the shed floor and temporarily nailed some blocks down to hold the pieces in place. After that it was a simple matter to lay down the parts between the blocks and glue and nail the gussets in place. I put gussets on both sides of all but the end trusses. They got them on one side only because the sheathing went on the other side. I built 9 trusses for my shed. The assembly took less than an hour.

Oh, and I laid out the gussets on the ply so I couldcut them quickly. They were laid on in rows so I could rip long pieces on the table saw. Then they were crosscut at the desired angles on the compound mitre saw. With a stop set on the CMS, I didn't have to do any measuring after the first one.

 

[les chicken]

Shultzy

If I am reading your post correctly : you intend using metal plates with predrilled holes and you want to use a nail gun to put the nails in.

If that is correct then you could be going down a disaster route. Nail guns are ideal for wood but to align one to fire through a hole in metal could result in a rerun of the OK coral. If you are slightly off line the nail could bounce or richoshay ( not the right spelling) back at you or fly any where.

Safer to use a hammer or devise a different method such as plywood brackets.

Les

 

[Shultzy]

Shultzy

If I am reading your post correctly : you intend using metal plates with predrilled holes and you want to use a nail gun to put the nails in.Les

I was going to do just that!. Because I havn't used a nail gun before, it didn't occur to me that this was a potential danger. Thanks

I think I will use nail-plates as this may be a quicker method than the gussets, (no glueing time)

PS. it's ricochet

 

[JFC]

So you want a flat roof with windows at the front ? Why not make up a window frame and cut an fix the rest of the roof ?
Or am i missing something ?

 

[mel]

im holding both my hands up . palms to the front
you lost me shultzy

 

[SketchUp Guru]

Shultzy, if you glue and nail ply gussets you don't have to wait for the glue to cure. The nails will hold the joints together while you move on to the next one. Once you've done one side of the truss you can flip it over and do the other side. Then you can set it aside. By the time you've completed the lot of them and are ready to install them, the glue will have cured and you'll have all that strength.

 

[Shultzy]

mel and john, and all, hope this pic will help, its the roof trusses and the front and back walls. I don't want a flat roof, too much trouble. The extra light will come in through glazings above the black front wall. I omitted the roof for clarity.

 

[mel]

shultzy

theres a lot of un-necessary work involved here IMO
why not , use 9x2 {wall plate to wall plate} and add a firing lat to give the fall you need ???
so much easier . and without the need for nailplates and nail gun
what youve got is basically a flat roof with a cant/tilt
just my opinion FWIW

 

[JFC]

I agree with Mel , This would give you better head room inside also .
Im not sure the angle your looking to make will work with a truss , isn't there a minimum degree before the fixing plates become a weak joint ?
I would make a window frame up and use that to support the front of the roof .

 

[SketchUp Guru]

I didn't realize that you were building a flat roof. I don't know if you have access to them there but over here, I would probably use manufactured floor joists for something like that. They are essentially a wooden I-beam. Might give you a bit more height than you want but they are fairly inexpensive, you'd have room for insulation and with an air passage above to keep the underside of the sheathing dry and you could even run wiring for lights above the ceiling.

 

[jasonB]

I'd be inclined to make the front stud wall the 18" or so taller than the rear then use 6x2 for the roof joists should be ample for that span and will give extra clear headroom.

Jason

 

[Shultzy]

I've put a couple more pics which show a bit more detail

Mel and John - I have designed it as a pent roof, which needs about 6deg if the method of covering is just heavy felt. The reason for this is I can use the space above head hight for small offcuts of timber, dowling etc and I can put the lighting in this area as well.I understand what you mean with the 9x2 and firring laths as I used this method on my house extension.

JFC - The angle of the roof is 6deg and I chose the nail plates as these are how the trusses(4x2) are made in my house which has a pitch of 30deg.

DaveR - It isn't a flat roof as maybe the extra photos will show. See comments above.

JasonB - For the span of 8'8" a beam of 8x2 is required, which is why I went for a truss design.

 

[JFC]

You cant take the plates on a 4x2 roof at 30* and apply it to a roof of 8x2 at 6* . The loads are totaly different .
](*,)