Screwing of the subfloor

[Chae]

Apology in advance as I do not have a picture as I'm working on the AS at my friend's place...

My subfloor was secured to the frame by what looks like a self-tapping screw with a very large flat phillips head. About half of them were rusted out so I need to find more. I've been browsing and looks like most people had the subfloor secured with flat head elevator bolts. But since I'm not dropping the belly skin, that's not going to be an easy option for me. I've been searching for past half an hour or so trying to find the exact replacement but have had no luck so far. It looks almost exactly like the flat head elevator bolt except with the phillips head, and the tip is tapered to a blunt point so I'm guessing it's not self-tapping but self-threading into a pilot hole...

Any ideas on where I can find a replacement? Thanks!

[HiJoeSilver]

Out of doors mart is where I got mine.

http://odmrv.com/catalog/index.php?m...roducts_id=638

Pre drill slightly smaller hole and it goes pretty smoothly.

[Unka Jack]

Vintage trailer supply also has them. Wonderful service, quick delivery.

[HiJoeSilver]

Originally Posted by Unka Jack

Vintage trailer supply also has them. Wonderful service, quick delivery.

The ones from VTS are different. The ones from OODM are exact match. I bought both when putting my new floor down. I used the ones from OODM, they had wider heads and I thought they held better in some trials on scrap.

[Melody Ranch]

Any trailer shop will have them....so will Home Depot, Lowes, or ACE. They are trailer floor screws....imagine that.

[tjdonahoe]

They are trailer decking screws, the best ones come from a bolt store like fasteners.....and use a torks adapter...

[Kemblkr]

You want to use wafer head 1 7/16" #3 Philips head self taping screws. You will not need to predrill going into the metal frame. These are size #14 or 1/4". Fastenal has them for cheap.

You need the 1/4" screws for strength and the wafer head will sink nicely into plywood or osb leaving a nice flat surface and a lot of grab!


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[missy crissy]

New question: do you use the original holes for the screws or do you drill new ones?
I'm just about ready to install the new subfloor and was wondering how to pre drill the wood to line up with the original holes. Drilling new holes would be a lot easier.

[youngpeck]

Originally Posted by missy crissy

New question: do you use the original holes for the screws or do you drill new ones?
I'm just about ready to install the new subfloor and was wondering how to pre drill the wood to line up with the original holes. Drilling new holes would be a lot easier.

I drilled new holes. Dripped a little spar varnish into each drilled hole prior to placing a screw.

[HiJoeSilver]

Drilled new ones. To use the old ones you'd almost have to drill pilots from below. Even that would be difficult because the crossmember gets in the way of a drill going straight up. Spray a little galvanizing paint or rustoleum in the hole if you have any. Protects the newly exposed metal from rust. Although all the original ones in my '79 were still tight and holding well.

[missy crissy]

Just what I thought. Good tips about spraying with Rustoleum before screwing the floor down.

[Wabbiteer]

I see other types of screws being mentioned but here's what worked well for me...

With the belly skin off I used a 12" 5/32" bit to drill upwards to get dead center on stamped metal flooring spars, the 1/2" offset is not much and/or is easily corrected for by bending the drill a teensy bit after it has pierced the metal spar so its truer to plumb as it goes through the flooring. Having a helper up top standing on an oversized backer board to keep from chipping the plywood as the drill bit pops through makes it a smooth procedure, though you could weigh down a 7' long board above and do the same thing.

My '73 used these floor screws, do not drill the pilot holes too large as these are self-drilling and use the metal it doesn't cut but shoves out of the way to increase the strength of the threads bite to the screw. Also, some countersinking to get the wedge of the head flush with the plywood might be needed, get a especially hard spot on the plywood and it might strip the threads trying to pull it down flush...

[Kemblkr]

All I know is the wafer head from Fastenal do not require a predrill. I would just drill new holes. Locating the original holes would be time consuming at best. Just make sure you have your screw plan established so you don't drill into gray tanks or wires or plumbing. Use the same amount of replacement screws as you removed approximately.

A was actually amazed how easy they went into the framing. Figured predrill was going to be a requirement. Pre drilling would not hurt though depending on the type of fastener. Just set your bit depth the same as the screw length.


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