Originally Posted by "nat_ster":fwhi1jj0
...Please for your own sake, do not use drywall screws anywhere in a bus. They are made of vary high tensile steel and break realy easy. I can snap them with my bare fingers.
Same go's for most general purpose construction screws including deck screws. If moved sideways, they snap. A nail would bend 16 times before breaking. This is why nails are used in home building, not screws.
Nat, I used drywall screws for a lot of the wood stuff I built in my bus, and so far haven't had any problems. I do, however, share your reservations about how brittle they seem to be. In your post you seem to be recommending nails? Wouldn't nails be more likely to loosen up in a mobile application? What type of screws would you recommend, if any?[/quote:fwhi1jj0]
Sorry Dan, I was over tired last night, and should have chosen my wording a bit more carefully.
No to nails. Not in a mobile application. The reference to nails was only a comparison in the material used to make the fasteners.
Screws are definitely the choice for a mobile application. Depending on where they are being used in the build,will determine the type of screws to use.
Wood to steel, like hanging your cabinets, I would use a machine screw. They are made more like a grade 8 bolt, with threads that can cut into and hold the steel.
Wood to wood in shear, I would use a number 8 deck screw up to 2 inches long. Beyond that length , they snap off quite easily. However, if the panel is pulled tightly against the other under compression, the screw will not be able to move sideways, and longer may be used.
For applications like steel joist hangers, post hangers, hurricane straps ect, to wood, the company that make these parts sell structural screws for this application. They are made of a more flexible steel, with a 1/4 socket head for driving them. Most times these screws are number 10s.
Believe it or not, a 1/2 inch crown framing staple will hold more than a nail. They are coated with a glue that is activated by the friction of driving them with the air stapler. They will bend back and forth about 10 times before breaking. Pulling them out is imposable.
For reference, drywall screws are number 6. Holding power without compression, 2 pounds. Holding power with full compression of material 20 pounds.
Deck screws up to 3" are usually a number 8. Holding power without compression, 10 pounds. Holding power with full compression of material 75 pounds.
Structural screws are usually a number 10. Holding power without compression, 40 pounds. Holding power with full compression of material 150 pounds.
The main reason why drywall and deck screws are made from such high tensile steel, is the method used to drive them. There is a lot of torque on that little spot where the bit fits in the head. This is why cheaper brands strip out the heads so much worse than a good quality screw.
This is only a sample of the way over complicated engineering tables of modern fasteners in residential home building. Hope it helps.
Originally Posted by JakeC
My entire bus is built with these. Most components contacting steel were also glued with construction adhesive.
BTW, Nat, you must have been bored last night. Some serious grave digging going on, haha!!
Gluing and screwing is a good Ida. Screws pull it up tight, glue sets, not only holding in sheer, but also making up for any space that was left between the ply's. As time go's on, construction adhesive only get harder.
And yes Jake, you are spot on. I have bus fever so bad, I could not sleep last night due to not getting the time to work on my buses for two days.