Attaching floor to frame + one more question?????

[S. Heisley]

Thanks for indulging me. By the way, you are an excellent writer.

Sharon

[shoeman]

Hey, back on topic, I found some screws at Lowes that should work just fine for attaching the floor to a square tube frame. I did a test set up using scrap from my floor and floor framing into a left over section of tongue steel. Penetration is adequate and the screw grips the steel VERY tightly. The wood does not want to move or pivot around the screw at all. They were about $7.00 for a box of 100. I drilled a pilot hle in the steel as the screws will not cut through it by themselves.
So here's an off the shelf readily available alternative.

[S. Heisley]

Those guys look good but I can't tell how big they are. I'm using a #8 wood screw on my wood to wood material and that's pretty small. If a #12 is just 30% thicker, I might get something thicker.

The box does show them being used for what looks like wood deck to metal frame but it doesn't show what size the final deck and metal base is . That can make a difference.

I'd want something at least 3/8 inch thick going through the metal to attach the deck so the screws/bolts don't snap off under any pressure.

Just my opinion.....

[tinksdad]

Again..... I don't want to beat a dead horse..... BUT......

back when (yeah .... I know everybody has a back when!!) I was rebuilding buses for a living the only thing holding the side and roof framing together was pretty much the 3/4" plywood flooring and the actual skin material for the outside. We used 1/4" and/or 5/16" elevator bolts. Granted the skins were 1/4" buck riveted to the frames, but here we are discussing 45' as opposed to maybe 10 or 12'.

[S. Heisley]

We used 1/4" and/or 5/16" elevator bolts. Granted the skins were 1/4" buck riveted to the frames, but here we are discussing 45' as opposed to maybe 10 or 12'.

Hi, Tinksdad:
How far apart were they bolted on your buses? Is it possible that frequency in the bolting pattern plays a part in the size of bolt used?

Do you know how thick, in inches, a size #12 bolt is? I went out to the garage and looked at what I had that was labeled. A #8 was about 1/8"; a #6 was slightly less than 1/8". Following that information, I suspect a #12 would be less than even 1/4" thick and might be "iffy" as far as strength goes.

Perhaps Mr Shoeman can measure the thickness of his bolts to see that they are thick enough to stand up to any possible stress?

[shoeman]

I just ran out to the garage to measure one.. they are 3/16" diam. at the root of the thread. They caught my eye in the store because they looked similar for the most part to the "deck screws" that are mentioned often as being used for this application.
JuneauDave uses those. Dave, if you're listening, what are the specs on those things?
As he did, I thought to space them every 12" to 16" around the perimeter. Many smaller fasteners or fewer larger ones is how it usually works in regards to strength of a joint I think.

[S. Heisley]

....I thought to space them every 12" to 16" around the perimeter. Many smaller fasteners or fewer larger ones is how it usually works in regards to strength of a joint I think.

This thread is exactly what I ran into when I asked about deck to frame attachment from local home and auto experts. Ultimately, the controversy of which is better: 'few and larger' or 'many and smaller' may depend upon which is better for the circumstances: the type and style of the metal chassis being used. With the weight and size of a teardrop, it may not matter which method is used, as long as it is not 'few and smaller'!

I agree that it would be good to hear what JuneauDave has to say.

[shoeman]

I agree that it would be good to hear what JuneauDave has to say.

Yeah. Let's PM him!

[shoeman]

Done. PM'd a minute ago. Now we wait.

[Juneaudave]

Hey guys...I used 1/4 x 2 1/2 inch trailer deck screws. They have a bugle head and require a torx bit. Hope that helps!!!

[shoeman]

Thanks Dave. I just found them at Redneck. In my case I don't think the difference between the 1/4" you used and the 3/16" I found is enough to worry about since I'm going to use plenty of them. They are listed as High Strength steel, whatever that is who knows, so that is a plus too.
Maybe I'll do some destructive testing over the weekend just to set my mind at ease.

[S. Heisley]

Obviously, one adage that is on my list:

"It is always best to err on the side of caution."

Good Luck on your project and thanks for all your kindness. I am certain you will do a great job on it.

Sharon

[2bits]

I drilled four holes through the floor that go through the 2x2 frame all the way. Then I got a 3/8" Bolt and tightened it down. didn't countersink since it was just 1/2" wood, but I am fine with it.



you can see the placement on the right side of this photo:

[tinksdad]

I used "self tapping deck bolts" that are commonly used on trailers. You just drill through your floor into the top of the tubing and screw them in. They self tap and work very, very well. I spaced them about a foot apart on the perimeter and every so often in the field. I think Rich turned me on to them and somewhere there is a post about them.

I don't have a pic.... but these are available at Lowe's as well in a variety of sizes. they use a phillips driver bit and are self drilling.... no pilot holes. The Lowe's I checked had them in all the # sizes plus 1/4" and 3/8".

Just a "for what it's worth"!!

[ArtMini]

ok heres what I have planned for my floor in the morning. 3/4 ply bolted directly down to the C channel frame. Since its a bolt together frame, and I already welded all the joints, I'm going to take out all the top 3/8 hex head bolts and replace them with 3/8 carriage bolts. I'll counter sink them slighty so the heads are flush with the floor. I'm planning on using roofing cement to coat it underneath. It claims it dries to a rubbery texture which is what I want, I think, how does this sound?

Art